63792 Solutions Fall 06-FINAL, page 1-40 @ Normalize - MESco

Industry Spotlight 

Researchers used ANSYS 

simulation technology to develop 

a housing for satellite electronic 

circuits that is 30 percent lighter 

than comparable structures. 

The latest addition to the ANSYS 

family, FLUENT 6.3 offers new 

CFD solver, modeling and other 

options. 

ANSYS CFX software improves 

the design of a hydro-generator 

for use in remote areas.

Contents 


6 

Features 

11 

14 

16 

20 

Factory and Plant 

Equipment 

Simulation-driven design plays a 

major role in developing industrial 

machines for manufacturing and 

process facilities around the world. 

ANSYS, Inc. Welcomes 

Fluent Inc. 

ANSYS broadens its opportunities 

to provide leading-edge engineering 

solutions with the acquisition of 

Fluent Inc. 

FLUENT 6.3: Major 

Advances in CFD Simulation 

The latest addition to the ANSYS 

family features new solver, modeling 

and other options — resulting in 

greater speed and flexibility. 

Analyzing Composites for 

Satellite Components 

Researchers used ANSYS software 

to study the behavior of a composite 

housing for electronic circuits and 

quickly developed a design nearly 

30 percent lighter than a comparable 

aluminum structure. 

CFD Simulation 

Brings Electrical Power 

to Rural Areas 

ANSYS CFX software improves the 

design and efficiency of a small 

hydro-generator for use in remote 

areas of developing countries. 

Departments 

About the cover 

Editorial 

Tools for Product and Process Innovation ...................2 

Industry News 

Announcements and Upcoming Events .........................3 

Guest Commentary 

Integrating CAD and CAE to Enable 

Simulation-Driven Design ...................................................................23 

Simulation at Work 

CFD Simulation Recreates Aviation History ...............24 

Weight-Optimized Design of a Commercial 

Truck Front Suspension Component ..................................26 

Developing Construction Products 

with Better Fire Performance .........................................................28 

Technology Update 

Bringing High-Performance Computing 

to the Mainstream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 

Tech File 

Running Solutions from Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 

Tips and Techniques 

Working with Coupled-Field Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 

Companies in the factory and 

plant equipment market use 

engineering simulation extensively, 

meeting the challenges 

of developing cost-effective, 

high-precision and efficient 

industrial machines that 

must operate under harsh 

conditions. Read more in 

this issue’s Industry Spotlight 

article beginning on page 6. 

For ANSYS, Inc. sales information, call 1.866.267.9724, or visit www.ansys.com. 

To subscribe to ANSYS Solutions, go to www.ansys.com/subscribe. 

Editorial Director 

John Krouse 

jkrouse@adelphia.net 

Designers 

Miller Creative Group 

info@millercreativegroup.com 

Ad Sales Manager 

Beth Mazurak 

beth.mazurak@ansys.com 

Editorial Advisor 

Kelly Wall 

kelly.wall@ansys.com 

Managing Editor 

Fran Hensler 

fran.hensler@ansys.com 

Art Director 

Dan Hart 

dan.hart@ansys.com 

Circulation Manager 

Elaine Travers 

elaine.travers@ansys.com 

Editorial Contributor 

Chris Reeves 

chris.reeves@ansys.com 

ANSYS Solutions is published for ANSYS, Inc. customers, partners and others interested in the field of design and analysis applications. 

Neither ANSYS, Inc. nor the editorial director nor Miller Creative Group guarantees or warrants accuracy or completeness of the material contained in this publication. ANSYS, 

ANSYS Workbench, CFX, AUTODYN, FLUENT and any and all ANSYS, Inc. product and service names are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries 

located in the United States or other countries. ICEM CFD is a trademark licensed by ANSYS, Inc. All other trademarks or registered trademarks are the property of their respective 

owners. POSTMASTER: Send change of address to ANSYS, Inc., Southpointe, 275 Technology Drive, Canonsburg, PA 15317 USA. 

©2006 ANSYS, Inc. All rights reserved. 

www.ansys.com ANSYS Solutions | Volume 7, Issue 4 2006

Editorial 

2 

Tools for Product and Process Innovation 

Simulation technology enables companies to stand out from the crowd with 

knock-out designs and leading-edge product development processes. 

Innovate or evaporate. That’s 

the new business imperative. 

Until recently, getting a product 

to market faster, cheaper and 

better than the competition 

usually was good enough. 

Not anymore. Now — in addition 

to time-to-market, cost and 

quality — manufacturers must 

focus on innovation: designs 

By John Krouse that take the market by storm 

Editorial Director and leading-edge development 

ANSYS Solutions processes that transform 

jkrouse@adelphia.net 

conceptual ideas into saleable, 

reliable and cost-effective 

products. 

Products must stand apart from others, breaking 

new ground in performance, size capacity or other 

attributes that compel consumers to pick a particular 

item from among many, or that influence OEMs to do 

business with one supplier over another. In many 

cases, companies improve existing products with 

imaginative functions and enhancements. Other times 

they create whole new classes of products that totally 

dominate a market segment as competitors scramble 

to catch up. In a world economy of radical change and 

fast-moving trends, innovation has emerged as the big 

market differentiator. 

Innovation is clearly on the minds of top executives, 

as reflected in a second annual survey on the 

topic conducted by The Boston Consulting Group in 

conjunction with BusinessWeek magazine. They 

received input from 1,000 senior managers worldwide, 

making it their “deepest management survey to date 

on this critical issue.” The report, “The World’s Most 

Innovative Companies,” discusses the importance of 

design as a differentiator as well as how companies 

are rewiring themselves to operate differently, with 

72 percent of senior executives in the survey naming 

innovation as one of their top priorities. 

One of the most interesting parts of the report is a 

list of the top 25 innovative companies. Of the top 20, 

14 are industrial companies — and ANSYS users. The 

others include a coffeehouse chain, retail stores, air- 

lines and Internet firms. Last year’s list reflected much 

the same. 

The use of ANSYS by the world’s most innovative 

companies comes as no surprise, of course. 

Simulation-driven design is the basis for innovative 

development processes and product concepts at a 

wide range of companies in nearly all manufacturing 

industries. The ability to quickly perform what-if 

studies and readily evaluate alternative designs 

gives engineers valuable insight into product behavior, 

lets them make intelligent trade-off decisions and 

provides the freedom not only to imagine way-out 

ideas but to easily test their feasibility. Design 

optimization and sensitivity studies augment 

engineering creativity and serve as guides to creative 

solutions that are not always intuitively obvious. 

Using these and other wide-ranging capabilities, 

virtual prototyping can simulate an entire system or 

subsystem in its operating environments to study and 

refine real-world product performance, thus enabling 

engineers to develop workable innovative designs for 

products that otherwise might turn out to be flops in 

the market because of performance, warranty or 

reliability issues. Moreover, visualization of analysis 

results that vividly depict product performance 

facilitates close collaboration and synergy between 

members of multidisciplinary teams in which people 

synergistically create imaginative design concepts 

that might not have surfaced otherwise. 

In this manner, simulation-driven design leverages 

the creativity of engineers and the intellectual 

capital of the enterprise. This elevates the approach to 

a strategic role as an innovation enabler, allowing 

manufacturers who make smart use of the technology 

to establish their brand value, strengthen their market 

position and boost top-line revenue growth by 

developing winning products.■ 


Industry News 

Recent Announcements 

and Upcoming Events 

3 

ANSYS Chosen as CAE Software for Chinese 

Mechanical Design Engineer Qualification 

The Chinese Mechanical Engineering Society (CMES) 

and the Examination Center of Ministry of Education 

have formally incorporated ANSYS software into 

China’s national Mechanical Design Engineer (MDE) 

qualification examination. MDE certification was begun 

in China in April 2006. It is designed to improve the skill 

level of professionals in the Chinese manufacturing 

sector, which also widely uses ANSYS software for 

computer-aided engineering (CAE). 

CMES is a professional society engaged in promoting 

the art and science of mechanical engineering 

throughout its host nation. In 2005, the Mechanical 

Design Institution (MDI) of CMES approached ANSYS 

China about using the software in developing a 

standard examination to certify mechanical engineers. 

The first-ever MDE qualification examination was held 

in test centers located in eight Chinese provinces, with 

619 students from more than 20 renowned universities 

participating. More than 400 passed the exam and 

received the MDE qualification certificate. 

ANSYS Named to Honor Roll 

ANSYS, Inc. has been named to the software industry 

Sustained Success Honor Roll TM for the third consecutive 

year. Culled from a list of more than 500 public 

software companies compiled annually by Cape Horn 

Strategies, ANSYS is one of 20 that made the 2006 

honor roll. 

Companies included in the list have an outstanding 

record of growing profitability for the past five 

consecutive years or more. With 10 consecutive years 

of profitable growth, ANSYS is the only engineering 

simulation software company that made the Sustained 

Success Honor Roll, as well as one of only eight 

software companies that reported at least 10 consecutive 

years of growing profitability. According to analysis 

firm Cape Horn Strategies, honor roll members 

significantly outperformed industry averages. 

ANSYS Software Offers 64-bit Support for 

Microsoft Windows Compute Cluster Server 2003 

The upcoming releases of ANSYS multiphysics 

simulation software — ANSYS 11.0 and FLUENT 6.3 

— will include support for Microsoft Windows 

Compute Cluster Server 2003. Enabling high-performance 

computing (HPC) on the Microsoft Windows 

platform, the new solution helps customers deploy 

computer-aided engineering at a higher level than in 

the past, decreasing the time required for simulations 

and increasing the accuracy of results. 

ANSYS 11.0 and FLUENT 6.3 take advantage of the 

Microsoft Message Passing Interface (MPI) software 

layer in Windows Compute Cluster Server 2003 for 

data communication between processors on the 

cluster. The new releases also use the Microsoft Job 

Scheduler in Windows Compute Cluster Server 2003, 

providing an off-the-shelf solution for launching and 

controlling jobs on the cluster. 

Fluent CAD Connection Software Facilitates Link 

between Design and Simulation 

The recently released Fluent Connection 1.1 software 

helps streamline the process of creating simulation 

models based on design data from leading computeraided 

design packages. Integrating core CAE 

technologies with the most popular independent 

design tools has been a key part of the ANSYS 

strategy for nearly a decade; this latest release brings 

direct integration to the Fluent products as well. 

Fluent Inc. recently was acquired by ANSYS, Inc. 

The Fluent UGS-NX TM Connection, Fluent Pro/ 

ENGINEER ® Wildfire ® Connection and Fluent 

Solidworks ® Connection products operate within the 

CAD system user environments and provide tools for 

checking and conditioning the 3-D geometry model in 

order to ensure that it has been properly prepared for 

the next step in the simulation process. Using Fluent 

Connection, CAD users can eliminate or repair 

geometry issues that would otherwise impede the 

simulation process. By providing a well-defined way 

to check the CAD model for possible simulationrelated 

issues, Fluent Connection helps engineering 

organizations ensure a streamlined hand-off between 

CAD and simulation. 


Industry News 

4 

Upcoming Events 

EuroBLECH – 19th International Sheet Metal 

Working Technology Exhibition 

Hanover, Germany 

October 24 – 28, 2006 

www.euroblech.com 

24th CADFEM Users’ Meeting 

Stuttgart, Germany 


www.usersmeeting.com/index.21.0.html 

ANSYS Users Conference 

San Miguel de Allende, México 


www.grupossc.com 

2006 Korea ANSYS CFX User Conference 

Pusan, Korea 


www.anst.co.kr 

Taiwan ANSYS User Conference 

Taipei, Taiwan 


www.cadmen.com 

ANSYS User Conference 

Singapore 

November 2 – 3, 2006 

www.cadit.com.sg 

Benelux ANSYS User Conference 

Breda, Netherlands 

November 3, 2006 

www.infinite.nl 

China ANSYS User Conference 

Sanya, China 


www.ansys.com.cn/conference/con_06 


Rio de Janiero, Brazil 


www.softec.com.br 

MicroMachine Conference 

Tokyo, Japan 


www.cybernet.co.jp 

Fluent France Forum 2006 

Paris, France 


www.fluent.com/worldwide/france/support/ugm06/ 

index.htm 

Italian ANSYS User Conference 

Stezzano, Italy 


http://meeting2006.enginsoft.it 


Bangalore, India 


www.ansysindia.com/index.htm 

ANSYS Latin American User Conference 

Florianopolis, Brazil 

November 9 – 10. 2006 

www.esss.com.br/ansys2006 

Fluent Germany Forum 2006 

Bad Nauheim, Germany 


www.fluent.com/worldwide/germany/support/ugm/ 

index.htm 

Electronica 2006 – Components Systems Applications 

Munich, Germany 


www.global-electronics.net/?id=20307 

Japan ANSYS User Conference 

Tokyo, Japan 


www.cybernet.co.jp 

Fluent Asia Pacific Users’ Group Meeting 

Tokyo, Japan 


www.fluent.co.jp 

Fluent Italy Forum 2006 

Milan, Italy 


www.fluent.com/worldwide/italy/support/ugm06 


Melbourne, Australia 


www.leapaust.com.au 

Fluent Forum 2006 

Madrid, Spain 


www.fluent.com/worldwide/spain/events/forum06.htm 

Euromold 2006 – World Fair for Moldmaking & 

Tooling, Design & Application Development 

Frankfurt, Germany 

November 29 – December 2, 2006 

www.euromold.com/splash/splash_em.html 



6 

From small job shops to giant superfactories and processing plants, facilities throughout the 

supply chain use production equipment to turn raw materials into products in the automotive, 

aerospace, telecommunications, electronics, heavy equipment, consumer products, 

petrochemical, pharmaceutical and food processing sectors, and even in service industries 

such as data processing, finance and insurance. 

Images courtesy Hatch Australia. 

Factory and 

Plant Equipment 

By Achuth Rao 

Product Manager 

ANSYS, Inc. 

Simulation-driven design plays a major role in 

developing industrial machines for manufacturing 

and process facilities around the world. 

To keep up with the increasing demand for 

manufactured products, companies rely on factory 

equipment including machine tools, injection 

molding equipment, robots, material handling 

equipment, stamping machines, welders and other 

industrial machines. 

In the competitive drive for factories and plants to 

produce more with less, the increased speed and 

efficiency of today’s technology-based equipment is 

credited as a major element in industrial productivity 

gains. According to the National Association of 

Manufacturers, manufacturing productivity grew 

4.8 percent last year. That’s a 78 percent jump 

compared to the economy as a whole and amounts to 

a 24 percent increase during the past four years. 

So to remain competitive, companies around the 

world invest heavily in the latest state-of-the-art 

production equipment. 

Statistics from the Manufacturing Performance 

Institute indicate that 20 percent of sales are 

re-invested in factory capital equipment in China, for 

example, and that 45 percent of U.S. plants expect to 


7 

increase their spending on production equipment in 

2006. According to the World Machine Tool Output 

and Consumption Survey, Japan ranks number one in 

terms of world output of machine tools and second in 

usage of this equipment. Meanwhile, figures from 

financial services firm JPMorgan specify that the rate 

of manufacturing expansion in the European sector is 

reaching a six-year high. 

On the flip side, industrial equipment buyers have 

a long list of demanding requirements. Machines must 

operate for decades under harsh conditions and often 

for multiple shifts, seven days a week. Downtime is 

unacceptable, since daily revenue losses can run into 

millions of dollars when production is halted. Energy 

efficiency is mandatory in lowering operating costs in 

the face of rising electric utility prices. Noise emissions 

must be low to meet strict regulatory standards. 

Vibrations must be minimized to avoid fatigue failures 

and unwanted resonances in precision machines. 

In addition, equipment must be cost-sensitive; new 

models must be launched quickly to meet fierce 

global competition. 

Companies in the factory and plant equipment 

market regard engineering simulation as an indispensable 

tool in meeting these challenges. ANSYS 

technology in particular is used by many of these firms 

in their product development cycle. A range of 

leading-edge solutions provides a breadth and depth 

of analysis capabilities including meshing of complex 

parts and assemblies, computational fluid dynamics 

(CFD), optimization, structural and thermal tools, and a 

wide range of multiphysics solutions. The ANSYS 

Workbench environment brings these technologies 

together in a unified suite of software. 

Boosting Machine Speed and Capacity 

Simulation technology plays a key role in efforts 

around the world to make industrial equipment more 

productive in terms of machine capacity as well as 

operational speed. Spain-based technological 

research center Fundacion ITMA, for example, 

performed a coupled thermo–structural analysis with 

ANSYS Mechanical software in developing a new 

design for a steel-making ladle — resulting in a 15 

percent greater capacity for handling liquid metal. 

Likewise, metalworking equipment manufacturer 

Gebr. Heller Maschinenfabrik GmbH in Germany uses 

ANSYS Mechanical in static, dynamic and thermal 

simulations of the metalworking equipment it 

develops, which includes transfer lines, machining 

centers, flexible manufacturing systems, and milling 

An ANSYS simulation model is superimposed on a representation 

of a Heller milling machine for manufacturing heavy truck 

crankshafts and camshafts. The handling system automatically 

transports the crankshafts into and out of the milling machine. 



8 

ANSYS Workbench was used at Robo-Technology in developing a system in which two precision robots work together in ultrasonic 

testing of helicopter parts up to six meters in length. 

and broaching machines. Typical simulations include 

deformation of parts, modal analysis and frequency 

response of the machines together with tools and 

workpieces, structural temperature distribution and 

topology optimization. In one recent application, Heller 

credits ANSYS simulation in achieving a 20 percent 

increase in operational productivity of a machining 

center for the production of automotive parts such as 

engine blocks, cylinder heads, transmission housings 

and chassis components. 

Building Better Robots 

According to the Robotic Industries Association, nearly 

1 million robots populate global manufacturing, with 

almost half working in Japan. Robots perform a wide 

range of production tasks including material handling, 

workpiece and tool positioning, arc and spot welding, 

packaging, and process applications such as inspection, 

testing, spraying and dispensing. Simulation is 

critical in developing these versatile machines for 

optimal speed, precision, lifting capacity and cost. 

German-based Robo-Technology recently used 

ANSYS Workbench tools to develop a six-axis robotic 

system for ultrasonic testing of helicopter parts up to 

six meters in length. The company reports that the 

ability to analyze the design throughout the development 

process enabled them to verify that the rigidity 

and vibration behavior of the system met customer 

demands of rapid testing movements, high dynamic 

precision and accurate synchronization among 

multiple robots working together. 

Similarly, Motoman Inc. in the United States used 

ANSYS DesignSpace software in developing a robotic 

overhead transport with a two-meter boom capable of 

carrying a 50-kg payload. Simulation technology is 

said to play a major role in the company’s product 

development group, which used ANSYS DesignSpace 

to create a boom with less mass so engineers could 

increase the reach and payload of the equipment. 

Insight into Complex Equipment Behavior 

Simulation is a powerful tool for better understanding 

the behavior of complex industrial machines. With this 

insight, engineers can then more effectively optimize 

designs and develop innovative concepts. The Non- 

Ferrous Metals Technology Group of Hatch Australia 

uses advanced analysis tools such as CFD for design 

evaluation, optimization and problem-solving in which 

heat transfer, fluid flow, combustion and mass transfer 

are critical issues. Hatch is a leading engineering 

consulting firm specializing in scale-up of process 

technology from prototype pilot systems to large 

production systems. 

In one project, researchers used ANSYS CFX 

software in analyzing a multiphase grinding mill 

that vigorously stirs incoming material together with 

solid grinding media using a series of high-speed 

rotating disks. The CFD analysis showed the complex 

multiphase swirling flow through the mill’s intricate 

geometry and the nature of media distribution, 

secondary flows and wear characteristics of parts. In 

this way, simulation has improved the understanding 


9 

of mill behavior for scale-up of the design and also has 

generally enhanced mill operation. 

Adding Revenue by Shortening the 

Development Cycle 

Computer simulation reduced time needed to develop 

a new aggregate drying burner designed for use in 

asphalt plants from the normal six to 12 months to 

only 32 days. Manufactured by Astec Industries in the 

United States, the burner is intended to remove 

moisture from rock so it will bind properly to cement in 

forming asphalt. Getting dryers to market as quickly as 

possible necessitated development of the burner in 

an extraordinarily short time, yet there was barely 

time to build a single prototype. 

The Astec design team used FLUENT CFD technology, 

recently added to the ANSYS suite of software 

solutions, to readily evaluate numerous virtual prototypes 

and quickly iterate to an optimized design. The 

primary concern was determining the best way of 

injecting fuel to obtain an optimal gas mixture. CFD 

saved considerable time by determining the flow and 

chemical concentrations early in design, providing far 

more information than ever would have been possible 

with physical experiments. In only two weeks, a 

working prototype was built; within a month, the 

design was optimized to meet stringent emission 

regulations. In this way, simulation drastically 

reduced time-to-market, thus providing up to a year 

of additional revenues while substantially reducing 

engineering costs. 

In developing an asphalt plant burner, CFD simulation shows 

velocity contours and pathlines indicating flow distribution around 

the fanwheel (top). Diffusive mixing of methane is indicated by 

pathlines around the gas injection pipe assembly (bottom). 

Images courtesy Astec Industries. 

More Time for Better Quality and 

Greater Innovation 

ANSYS structural analysis software is a core tool 

for the state-of-the-art development facility at the 

headquarters of Husky Injection Molding Systems Ltd. 

in Canada. The company designs and manufactures 

the plastics industry’s most comprehensive range of 

injection molding equipment, including machines, 

molds, hot runners and robots. 

In developing these large injection molding 

machines, engineers face demanding design 

challenges. Machine weight must be minimized to 

keep manufacturing and transportation costs low. 

Operating speeds must be fast enough for required 

throughput of manufactured plastic parts. Reliability 

and precision must be maintained to provide 

satisfactory service with minimal downtime. Efficiency 



10 

is a requirement to keep energy consumption low and 

thus minimize operating costs. 

Engineers at Husky met these challenges with 

ANSYS Workbench and ANSYS DesignSpace tools. 

The integrated solutions provided efficient contact 

representation for complex nonlinear assembly 

analysis, additional pre-analysis in construction 

and the benefit of common simulation methods in 

the various types of analyses. Engineers report 

that analyses formerly taking a week now can be 

completed in just half a day. This level of increased 

analysis efficiency is said to enable development 

teams to achieve better machine quality and greater 

innovation in products such as the company’s new 

Reflex platens. 

New Rotodynamics Capability Increases 

Analysis Productivity 

Design analysis of parts and assemblies in the 

industrial machinery industry involves complex 

computer-aided design (CAD) assemblies. To 

accurately handle these geometries in the design 

process, ANSYS offers close connection with CAD 

to access geometry and material parameters; it also 

allows quick turn-around while preparing geometry for 

analysis. Geometry creation and editing tools allow 

geometry manipulation for physics-based meshing 

and analysis. 

U.S.-based Trane, a business of American 

Standard, Inc. and a leading worldwide supplier of 

HVAC (heating, ventilating and air conditioning), uses 

ANSYS software to design rotating equipment in 

industrial chillers and air conditioning equipment using 

the new rotordynamics capability. The ability to import 

full 3-D CAD models into ANSYS Workbench allows 

the user to analyze accurate 3-D models instead of 

creating simplified 1-D representation of the geometry. 

Productivity tools such as automatic contact detection 

allow for easy problem setup and more time spent on 

engineering design decisions. 

To survive in the global economy of the third 

millennium, manufacturers need to be inventive in 

terms of factory equipment and raw materials, as well 

as with the processes they develop. Using simulationdriven 

design efforts can bring value and innovation to 

a wide range of product development applications. ■ 

The author wishes to thank development, technical support 

and marketing personnel at ANSYS, Inc. for their efforts and 

contributions to this article. 

Trane uses ANSYS geometry (top), meshing (middle) and dynamics 

(bottom) solutions to design HVAC systems and comprehensive facility 

solutions for factories and other large commercial and industrials. 

Images courtesy Trane, a business of American Standard, Inc. 


11 

Image courtesy 

Sheffield University. 

ANSYS, Inc. Welcomes 

Fluent Inc. 

ANSYS broadens its opportunities to provide leading-edge 

engineering solutions with the acquisition of Fluent Inc. 

By Chris Reid 

Vice President, Marketing 

ANSYS, Inc. 

On May 1, 2006, ANSYS, Inc. announced the completion 

of the acquisition of Fluent Inc., headquartered in 

Lebanon, New Hampshire. Fluent is a global provider 

of computer-aided engineering (CAE) products that 

utilize computational fluid dynamics (CFD) principles 

and techniques to enable engineers and designers to 

simulate fluid flow, heat and mass transfer, and related 

phenomena involving turbulent, reacting and multiphase 

flow. This acquisition reaffirmed the ANSYS 

commitment to providing the open interface and 

flexible simulation solutions that customers require. 

What follows is some background information 

to help you get better acquainted with the newest 

member of the ANSYS family. 

History of Fluent Inc. 

In 1982, when CFD was primarily of interest to 

academic specialists, engineers at Creare, Inc., a New 

Hampshire consulting company, collaborated with 

researchers at Sheffield University in Sheffield, UK, to 

develop an interactive, easy-to-use CFD software 

product for engineers. Called FLUENT, the first version 

of this software was launched in October 1983. The 

product was so successful that, in 1990, the FLUENT 

group at Creare split from its parent company, moved 

to a new location and formed Fluent Inc. 

Rapid expansion of Fluent’s software business 

ensued, and, in May 1996, Fluent acquired Fluid 

Dynamics International, the developer of the 

general-purpose CFD software FIDAP. In 1997, Fluent 

acquired Polyflow S.A., the developer of POLYFLOW, 

a specialty CFD software product for the analysis of 

materials such as polymers, plastics, food and rubber. 

Since its inception, Fluent has continued to 

innovate and grow by offering superior CFD software 

and services to companies around the world. 

Industry-Leading Technology 

The broad physical modeling capabilities of FLUENT 

technology have been applied to industrial applications 

ranging from air flow over an aircraft wing to 

combustion in a furnace, from bubble columns to 

glass production, from blood flow to semiconductor 

manufacturing, from clean room design to wastewater 

treatment plants. The ability of the software to model 

reacting flows, aeroacoustics, turbulence, moving 

meshes and multiphase systems has served to broaden 

its reach. Today, thousands of companies throughout 

the world benefit from using FLUENT software. 

The suite of Fluent CFD products includes 

FLUENT, FIDAP and POLYFLOW for CFD analysis; 

FloWizard, a rapid flow modeling tool that allows 


12 

Engineers at Wenger Manufacturing gained better insight into 

the operation of a vertical cascade dryer (used to manufacture 

pet food) by utilizing CFD. The consulting team at Fluent was 

able to provide Wenger with an understanding of the existing 

dryer in order to improve their ability to market, specify, apply 

and service it. Improved dryers allow food processors to meet 

guaranteed levels of product components, decrease costs and 

avoid recycling of fine particles that may detract from product 

appearance and present a fire hazard. Detailed airflow and 

pressure distribution in various sections of the dryer would be 

impossible to obtain through physical testing and measurement 

— but were possible to simulate using FLUENT software. 

Image courtesy Wenger Mfg. 

design and process engineers to quickly and 

accurately validate their designs much earlier in the 

product development cycle; FLUENT for CATIA V5, 

which integrates Fluent’s rapid flow modeling 

technology into the CATIA V5 product lifecycle 

management (PLM) process; and FlowLab, a studentfriendly 

tool that uses the power of flow visualization 

through CFD to teach basic fluid mechanics principles 

in the engineering classroom. Fluent’s products also 

include the preprocessors GAMBIT, TGrid and 

G/Turbo. Application-focused products include Icepak 

to optimize thermal management of electronics 

designs; Airpak for modeling airflow, heat transfer, 

contaminant transport and thermal comfort for the 

built environment; and MixSim for the simulation of 

stirred tanks. 

Fluent always has taken pride in understanding 

customers’ strategic goals and helping them come 

to fruition through both software and services. 

The complete array of services available addresses 

the specific needs of organizations and supports 

those organizations in implementing advanced 

technology solutions. Services include consulting, 

training and technical support. 

Extensive Simulation Community 

With the acquisition of Fluent Inc., ANSYS is pleased 

to welcome Fluent software users to the world’s 

largest simulation community. As a supplier to 94 of 

the FORTUNE 100, ANSYS serves a wide range of 

industries. They all have benefited from using ANSYS 

software products and services — which continue to 

expand, both with the addition of new technologies 

developed via innovative research and development 

and by acquisition, such as in the case of Fluent. 

ANSYS now has one of the broadest ranges of 

CFD simulation technologies in the world. ANSYS 

believes that success relies on ensuring customers’ 

satisfaction. As such, in addition to focusing on 

investment in product development, the company will 

continue to provide the best possible service and 

support through technical centers of excellence 

around the world. 

The addition of Fluent products to the ANSYS 

portfolio significantly enhances the combined company’s 

ability to provide world-leading simulation capabilities 

to customers, consistent with the ANSYS vision 

and strategy. 

Broad and Integrated Solutions 

ANSYS continues to concentrate on providing 

customers with best-in-class CAE tools integrated in a 

flexible manner that will enable easy and rapid analysis 

and optimization of engineering designs. 

Clearly, there is now the opportunity for tighter 

linkages between ANSYS products, such as ANSYS 

In this example, FLUENT software is used to optimize 

the cooling package for a line of tractors. The cooling fan 

characteristics, along with the placement of underhood 

modules, are varied to achieve optimum performance. 

Courtesy Case New Holland. 


13 

CFD is becoming critical to the furnace design process, particularly as environmental regulations become more stringent. To help meet 

these regulations, John Zink Company selected FLUENT software to assist in modeling flames for a vertical cylindrical furnace used in 

an oil refinery. By using FLUENT, engineers were able to improve fuel mixing in order to decrease NOx production and maintain flame 

height within the desired parameters. CFD modeling provided a proposed solution (right) to reduce burner interactions that had caused 

increased flame height (left). 

Image courtesy John Zink Co. 

Mechanical or ANSYS Multiphysics, and Fluent 

products, as the company has done already with 

ANSYS CFX. The benefits of this strategy to 

customers and the engineering simulation industry 

have been real and measurable in terms of increased 

innovation, greater productivity and lower costs. 

ANSYS, Inc. fully expects to extend the same benefit 

to today’s Fluent user community. 

With the addition of more than 700 new 

employees from Fluent and its subsidiaries, the 

combined team with many years of simulation 

experience, deep industry expertise and world-class 

engineering talent will deliver even more exciting 

advances in integrated CAE. To support the ability 

to provide industry-leading advancements, ANSYS will 

continue its focus on innovation and target approximately 

20 percent of revenue to be spent on R&D. 

Moving Forward 

ANSYS and Fluent always have had much in 

common. Now, the goals each company had for 

the future are shared, and progress toward 

these goals can be accelerated and fulfilled to the 

benefit of customers. As in the past, ANSYS will 

maintain a strong commitment to employees, partners 

and customers as well as to the advancement of 

technology through innovation. ■ 

Some of the world’s greatest soccer goalkeepers have been 

beaten by unusual swerving balls that move left then right 

before hitting the back of the net, even though they have little 

or no spin applied to them. A team of researchers led by 

Dr. Matt Carré at the Department of Mechanical Engineering, 

University of Sheffield used FLUENT to demonstrate that the 

shape, surface and asymmetry of the ball, as well as its initial 

orientation, have a profound effect on how the ball moves 

through the air after it is kicked. The image shows high-speed 

airflow pathlines colored by local velocity over the Adidas ® 

Teamgeist 2006 soccer ball. 

Image courtesy Sheffield University. 


14 

The new sliding mesh capability in FLUENT 6.3 

allows for many sliding interfaces within a 

single simulation. In the case of the V22 

Osprey, the rotating propellers gradually tilt 

as the craft lands on a platform, changing 

the propulsion from forward to hover mode. 

FLUENT 6.3: Major Advances 

in CFD Simulation 

The latest addition to the ANSYS family features new solver, 

modeling and other options — resulting in greater speed and flexibility. 

By Christine Wolfe, FLUENT 6 Product Manager, Fluent Inc. 

Nicole Diana, Product Planning Manager, Fluent Inc. 

The current version of FLUENT software continues to 

evolve, allowing difficult engineering problems to be 

solved faster and with greater flexibility than 

ever before. The upcoming release of FLUENT 6.3 

offers innovative technology for addressing a broad 

range of applications. In all, there are more than 100 

new features that enhance core numerics and physical 

modeling capabilities in areas such as moving 

mesh, multiphase flow, combustion, reacting flow 

and radiation. 

New Solver Options 

In FLUENT 6.3, a pressure-based coupled solver joins 

the existing solver options. The new solver can 

improve solution efficiency as well as convergence and 

robustness for many cases. With this solver scheme, 

the pressure and velocity equations are solved in a fully 

coupled manner, while the other equations are solved 

sequentially. It is particularly beneficial for “stiff” problems 

and for solving problems on unusually skewed 

and stretched meshes. 

In addition, existing FLUENT solvers have been 

enhanced to offer improved robustness, accuracy 

and efficiency. For example, strong shocks can be 

captured more effectively with the density-based 

solver, and transient simulations can be run more 

efficiently with the pressure-based solver. Furthermore, 

a new diagnostic case check algorithm can be used to 

assess case settings and offer recommendations to 

ensure that commonly accepted best practices are 

being used. 

Polyhedral meshes are being introduced in 

FLUENT 6.3. These meshes allow the flexibility of an 

unstructured mesh to be applied to a complex 

geometry without the overhead associated with a 

large tetrahedral mesh. The polyhedral meshes are 

created using automatic cell agglomeration to 

combine tetrahedral cells into polyhedral ones. This 

can reduce the overall cell count by a factor of 3 to 5. 

The automatic nature of these mesh agglomeration 

techniques saves the user time and, since the polyhedral 

mesh contains as few as one-fifth the number 

of cells in the original tetrahedral mesh, convergence 

is faster. 

In support of FLUENT software’s ongoing 

commitment to parallel processing, numerous 

improvements to parallel efficiency and flexibility have 

In FLUENT 6.3, a discrete phase 

of particles, droplets or bubbles 

can be launched from a surface 

at normal angles, as is shown 

for a Rushton impeller in a 

stirred tank. 


Nylon is injected into a mold in this simulation of the production of a plastic 

gear part. The plastic has non-Newtonian rheology, and the ratio of the nylon to 

air viscosities is very large. To address this complex free surface flow, a new 

interface tracking scheme in FLUENT 6.3 is used. 

been implemented along with speed improvements for 

reading and writing case and data files. High-performance 

computing also benefits from a 64-bit Windows 

version of FLUENT 6.3. 

New Modeling Options 

New models and extensions to existing models add to 

the technology’s capabilities in the areas of moving 

mesh, reacting flow, multiphase flow and radiation. 

FLUENT software’s industry-leading dynamic 

mesh capability for modeling moving objects — such 

as pistons and valves in IC engines, store, separation 

and impellers in baffled mixing tanks — has been 

enhanced. In FLUENT 6.3, the dynamic mesh 

capability can be applied to a series of related steadystate 

simulations, making them easier for users to set 

up and perform. For example, a control valve can be 

simulated with a range of open positions by building 

only one mesh and having FLUENT software rebuild 

the mesh for each new position. Other improvements 

make problem setup and user-defined mesh motion 

even more straightforward and efficient. 

In some cases, the motion of objects can be 

captured by using regions of mesh that slide along 

a common interface. This technique is useful for 

modeling two trains passing in a tunnel, for example. 

FLUENT 6.3 now is able to model more complex 

object motion by allowing for multiple sliding mesh 

regions on one side of an interface to be paired with 

multiple sliding regions on the opposite side. 

Reacting flow simulations benefit from new slow 

chemistry and micromixing models, useful for liquid 

reactions and certain combustion applications. A 

larger number of chemical species and reactions can 

be handled in the non-premixed and partially premixed 

combustion models. Emissions modeling is more 

comprehensive through the addition of SOx prediction 

and the selective noncatalytic reduction of NOx 

through urea injection. Expanded in-cylinder combustion 

capabilities include the ability to model ignition 

delay in stratified engines. 

Multiphase modeling continues to be an area 

of focus for FLUENT 6 development, and major 

improvements can be found in the accuracy of 

transient multiphase solutions. For the Eulerian multiphase 

model, enhancements extend the regimes for 

which this model can be applied. For example, both 

compressible gas and liquid phases can be present, 

and the mixing plane model can be used, simplifying 

the solution of multiphase flows in pumps. For free 

surface flows simulated using the volume of fluid (VOF) 

model, a new interface tracking scheme is available 

that improves solution stability when the viscosity ratio 

between the phases is high. FLUENT 6.3 technology 

also allows a user-defined function (UDF) to be utilized 

to specify the wall contact angle, allowing a dynamic 

value to be calculated from the local flow field. This 

feature is of primary importance for capillary-driven 

flows in which surface tension is important. 

For simulations involving surface-to-surface 

radiation, extensions to the existing model make the 

problem definition easier, and increase the solution 

efficiency and range of applicability. For example, this 

technique now can be used for 2-D axisymmetric 

cases, and the participating boundaries can be 

specified more easily in the graphical user interface. 

Add-On Modules and Third-Party Tools 

Several capabilities can be added to FLUENT software 

through add-on modules. A population balance 

module is new with FLUENT 6.3. This module makes 

it possible to model multiphase flows with a particle 

or droplet size distribution. Three approaches are 

available that account for breakup and agglomeration 

so that applications such as bubble columns and 

crystallizers can be modeled. The proton-exchange 

membrane (PEM) and solid-oxide fuel cell (SOFC) 

modules have been enhanced in FLUENT 6.3. 

For PEM fuel cells, transient simulations can be 

performed and electrical conductivity can be obtained 

from the FLUENT materials database. For the SOFC 

module, the range of conditions that can be simulated 

has increased. 

Another improvement in FLUENT 6.3 is the ability 

to work with third-party CAE packages. It is now 

easier to import and export files to and from other 

analysis tools (for fluid structure interaction, for 

example) and postprocessing tools (such as EnSight 

or Fieldview, for example). 

Along with many other features, these highlights 

make FLUENT 6.3 software a major step forward in 

commercial CFD capability. ■ 

The ability to solve on polyhedral meshes is 

new in FLUENT 6.3. Tetrahedral cells are 

agglomerated to form polyhedra in the solver, 

resulting in a reduced overall cell count that 

requires less CPU time to reach convergence. 

15 


16 

Analyzing Composites 

for Satellite Components 

Researchers used ANSYS technology to study the behavior of a 

composite housing for electronic circuits and quickly developed a 

design nearly 30 percent lighter than a comparable aluminum structure. 

By Harri Katajisto 

R&D Engineer 

Componeering Inc. 

Helsinki, Finland 

Scientific, observation and reconnaissance missions 

often are performed by low-orbiting micro-satellites. 

These systems are much smaller and more compact 

than larger telecommunications satellites, so space 

is severely limited and heat is more difficult to 

dissipate from closely packed electronic components. 

Traditionally, satellite electronics housings are made of 

aluminum. This material is lightweight, has adequate 

heat dissipation and provides good protection against 

ambient spatial radiation. 

In one recent study, the European Space Agency 

(ESA) investigated the feasibility of fabricating these 

housings of composites to determine if this type 

of material systems could provide the same heat 

dissipation as aluminum but with less mass. In this 

study, Verhaert Design and Development in Belgium 

Figure 1. The Proba 2 micro-satellite has instruments to 

make solar observations and space weather measurements. 

The electronics housing from this micro-satellite 

was used as a reference application in the ESA study. 

Image courtesy Verhaert Design and Development. 


Figure 2. The housing with its back panel removed shows 

composite laminate structures together with aluminum 

wedge locks and mounting rails. 

Photo courtesy LLS/HUT. 

provided the reference application for the study: the 

Advanced Data and Power Management System 

(ADPMS) aluminum housing for the Proba 2 microsatellite 

in Figure 1. Analysis of the composite housing 

was performed by Componeering Inc., which specializes 

in simulation and design of high-performance composite 

structures. The Laboratory of Lightweight 

Structures at Helsinki University of Technology 

was responsible for the design, prototyping and 

manufacturing of the housing, shown in Figure 2. 

The Challenge of Designing with 

Composites 

Designing composite structures with sandwich-type 

elements or layered solid laminates is very challenging 

due to the anisotropic behavior of the material. 

Moreover, the design depends on multiple variables 

such as material selection, number of layers, layer 

orientations and stacking sequence. 

In the structure under investigation, performance 

requirements for the composite housing were derived 

from the requirements of the aluminum housing. 

For example, the goal in radiation protection was 

to provide shielding against spatial radiation in low 

earth orbit comparable to the aluminum design with a 

2mm wall thickness. This was achieved by embedding 

tungsten foil inside the carbon fiber-reinforced 

plastic (CFRP) laminate structure of the housing 

external panels. 

One important requirement was that mechanical 

interfaces of the composite housing had to be 

identical to the aluminum counterpart. Inside and 

outside contours of the housing had to accommodate 

internal circuit boards and connectors as well as 

external components of the satellite. These constraints 

limited the composite design, in which smooth shapes 

are preferable. 

To provide thermal management comparable 

to the aluminum housing, heat dissipation for the 

composite structure was provided by layers of 

plastic reinforced with K1100 pitch-based carbon 

fibers. Combined with the plastic matrix as a ply 

configuration, these fibers yield about four times 

higher thermal conductivity in the direction of fibers 

than typical aluminum alloys. Moreover, the natural 

black color of CFRP provides high emissivity, and heat 

is dissipated very efficiently from the surface. From a 

structural standpoint, however, the K1100 fibers 

exhibit very low failure strain and break easily when 

bent on a small radius. 

Compounding the design challenge, mismatches 

in coefficients of thermal expansion (CTE) between the 

composite housing and aluminum wedge locks and 

satellite support structures cause deformations when 

the structure is subjected to temperature change. 

Because of these complexities, determining 

thermal balance, structural integrity and resonant 

frequencies of the housing using conventional analysis 

methods can be an extremely cumbersome task. 

Results would most likely have a high probability of 

error due to simplifications that would not adequately 

account for all design variables. 

Advanced Tools for Simulation and Design 

To meet these challenges, we performed a wide range 

of analyses using ANSYS Mechanical software 

throughout the project. During conceptual design, 

laminate through-the-thickness direction behavior was 

studied with a solid thermal model using SOLID70 

elements as shown in Figure 3. (See next page.) 

Analysis results demonstrated that single-layer 

elements are adequately representative for thin 

laminates in steady state, so only in-plane thermal 

conduction capability of the SHELL131 element was 

used. The effective conductivities of the laminate were 

verified easily with capabilities of SHELL131 and 

simple test models. Mechanical interfaces and 

adhesively bonded joints were modeled using 

thermal LINK33 elements, with contact resistance 

depending on joint materials, surface roughness and 

contact pressure. Input data definition for thermal links 

17 


18 

Figure 3. Representative 3-D model illustrates temperature 

variation in the laminate through-the-thickness direction (left) 

and high thermal flux in the two K1100 layers located on 

both surfaces (right). 

was based on a literature study. Both conduction 

and radiation heat transfer modes were considered. 

The radiation effect was applied using the SURF151 

element that was overlaid onto the SHELL131 

element. 

Thermal analysis of this type is readily performed 

in ANSYS software, which provides the capability to 

use nodal temperatures resolved from the thermal 

model as an input for the structural model. The use of 

this feature is very simple, since ANSYS internally 

converts the thermal results file *.rth to equivalent 

force and moment vectors in the structural model. 

In this study, in-service temperature variations in 

laminate structures were quite small, so thermal 

bending was not an important factor. However, thermal 

bending was found critical in some manufacturing test 

trials in which laminate structures were bonded at high 

temperature with aluminum wedge locks. For these 

cases, SHELL181 has proved to give excellent results, 

providing ease of controlling the laminate crosssection 

input data. 

The wedge locks do not fully cover the hat 

section in the depth direction, and ANSYS thermal 

analysis revealed that part of the heat-dissipation 

capacity was lost with K1100 layers oriented in the 

longitudinal direction of the housing, as shown in 

Figure 4. It was found that when K1100 layers were 

oriented in ±30 degrees, the temperature distribution 

was more homogenized, the peak temperature was 

the same and, structurally, the lay-up was acceptable. 

The stiffness requirements of the housing 

dictated the number of required structural M40J CFRP 

layers. The orientation and stacking sequence of both 

K1100 and M40J layers was based on the laminate 

stiffness and CTE. CFRP structures have slightly 

negative CTE in the fiber direction. Respectively, in 

the perpendicular direction to the fibers, CTE is in 

the magnitude of aluminum. The wedge locks were 

adhesively bonded to the laminate structures 

and acted like stiffeners. Due to this bonding 

and orientation, the CTE of the laminate was an 

important design parameter. 

The laminate design was performed using 

ESAComp software (www.esacomp.com), which is a 

dedicated tool for preliminary and detailed analysis of 

composite structures. ESAComp interfaces smoothly 

with ANSYS software. Laminate lay-ups and material 

data can be exported to ANSYS for composite solid 

and shell elements. Moreover, FEA results from 

ANSYS can be imported to ESAComp for detailed 

post-processing. This capability was used, for example, 

in studying the criticality of the laminate interlaminar 

shear (ILS) stresses, which became high close to the 

inserts that were used to attach different panels. 

Creating simulation models was facilitated using 

ANSYS Parametric Design Language (APDL), which 

could be linked to ESAComp for optimizing the 

design. With APDL, an external software such as 

ESAComp can be readily linked to the design cycle, 

thus allowing simulation to effectively guide the 

development process toward the best design. 

After completion of the thermal analysis with 

ANSYS software and laminate design with ESAComp, 

ANSYS Mechanical was used for structural analysis of 

the housing, including a modal analysis for natural 

Figure 4. ANSYS thermal analysis of the composite hat section 

revealed that heat-dissipation capacity varied according to 

the orientation of the K1100 layers of the laminate. 


Figure 5. The same ANSYS model was used for both structural 

and thermal analysis in determining characteristics such as 

the thermal balance of the laminate structures and mode 

shapes of the system. 

frequencies up to 800 Hz. Modal analysis results 

together with the random vibration input specification 

defined the acceleration levels for the subsequent 

failure analysis. The design was predicted to withstand 

load levels multiplied by factor of safety of two, 

which is a typical value for composite materials in 

space applications. 

In the ANSYS model for these structural studies, 

the quadratic composite SHELL99 element was 

used for meshing the laminate structures. SHELL99 is 

applicable to thin laminates, but it contains transverse 

shear deformations capability as well. Bolted joints 

and inserts were modeled using the BEAM4 element 

in order to be able to extract laminate bearing stresses 

and insert pull-out forces. 

Impact and Benefits of the Solution 

Thermal tests performed in the vacuum chamber at 

the European Space Research and Technology Centre 

(ESTEC) in the Netherlands corresponding to the 

worst hot temperature condition of the equipment 

confirmed that simulation accurately predicted 

the satisfactory heat-dissipation capacity of the 

composite housing. 

Using an electromagnetic shaker, sine and 

random vibration tests of a breadboard model were 

conducted at the Royal Military Academy in Brussels, 

Belgium. The composite housing was found stiffer 

than its aluminum counterpart, and overall behavior of 

the system was as predicted with simulations. 

In this project, ANSYS software worked smoothly 

in exchanging data with ESAComp. Time was saved in 

generating simulation models by importing required 

data directly from ESAComp into ANSYS, as well as 

taking advantage of automated features of ANSYS 

contact elements and power of APDL for parameterization. 

Considerable time also was saved through the 

ability to use the same ANSYS model for both 

structural and thermal analyses, as shown in Figure 5. 

In the course of the project, details of the composite 

structure were studied with simulation before going 

through the time and expense of building physical 

prototype breadboard models. In this way, the 

modified structure could be analyzed and feedback 

provided almost instantly to the design team. 

The ability of ANSYS software to work well with 

ESAComp, to provide a robust parametric model 

representing all the different components and to 

reliably perform both structural and thermal analyses 

was key to the speed and accuracy in successfully 

completing the study. With the help of this level of 

advanced analysis, the behavior of the structure could 

be properly understood, the design of the composite 

housing was optimized to provide a mass saving of 

29 percent over a comparable aluminum housing and 

the project was completed in only 18 months from the 

kick-off meeting to the final presentation of results. ■ 

Refer to the following papers for more information on 

this project: 

Katajisto, H. et al., “Structural and Thermal Analysis of 

Carbon Composite Electronics Housing for a Satellite,” 

Conference Proceedings of the 1st NAFEMS Nordic 

Seminar “Component and System Analysis Using Numerical 

Simulation Techniques — FEA, CFD, MBS,” Gothenburg, 

November 23-24, 2005. 

Brander, T. et al., “CFRP Electronics Housing for a Satellite,” 

Proceedings of European Conference on Spacecraft 

Structures, Materials and Mechanical Testing, Noordwijk, 

May 10-12, 2005. 

Jussila, J. et al., “Manufacture and Assembly of CFRP 

Electronics Housing,” Proceedings of European Conference 

on Spacecraft Structures, Materials and Mechanical Testing, 

Noordwijk, May 10-12, 2005. 

19 


Visualization of the turbine velocity vectors 

at the blade mid-span location 

20 

CFD Simulation Brings Electrical 

Power to Rural Areas 

ANSYS CFX software improves the design and efficiency of a small 

hydro-generator for use in remote areas of developing countries. 

By Robert Simpson, Ph.D. 

Nottingham Trent University, UK 

In developing countries, many remote rural communities 

do not have access to electricity due to the large 

expenses associated with extension of the national 

grid. Where these communities have access to a 

suitable site, small hydroelectric schemes are found to 

be a cost-effective and sustainable means of providing 

electricity. The Micro Hydro Research Centre at 

Nottingham Trent University has been carrying 

out research into small-scale standardized hydrogenerator 

units that are directly affordable for villagers 

in developing countries. 

Low-head hydro sites (2 to 10m) offer the 

potential for providing electricity to many communities, 

but progress has been hampered by the lack of an 

appropriate turbine design. A research project has 

been undertaken in collaboration with Practical Action 

Peru (formerly known as Intermediate Technology 

Development Group) to develop a standard design 

procedure for the cost-effective local manufacture 

of pico-propeller turbines with good performance 

and reliability. Pico-hydro is the smallest classification 

of power output with a maximum output of 5kW. 

Fixed geometry propeller turbines are one of the 

most cost-effective turbine options for low-head 

pico-hydropower. 

The first objective of the project was to design 

a simplified prototype turbine based on current 

knowledge and to have it manufactured and installed 

at a field site in Peru. Stage two involved analyzing 

the turbine using computational fluid dynamics (CFD) 


to improve the design and efficiency. Using CFD 

provides the flexibility to make design changes, 

investigate scale effects and vary the hydrological 

conditions (head and flow rate) without the need and 

expense of creating a prototype for each test case. 

ANSYS CFX software was used for all aspects 

of the CFD study because of its good track record 

with turbomachinery analysis and because it is 

part of an integrated system of software, which 

includes CFX-BladeGen (now ANSYS BladeModeler) 

and ANSYS TurboGrid for design and analysis of 

bladed geometry. 

21 

Prototype Turbine in Peru 

The prototype turbine for the project is located on a 

small farm in the northern highlands of Peru. Currently, 

the turbine is producing electricity for the owner’s 

farmhouse located several hundred meters away, and 

the horizontal shaft layout was designed to facilitate 

easy connection to existing mechanical equipment 

used by the farmer to produce feed for several chicken 

farms. Water for the turbine is diverted into a concrete 

channel from an existing irrigation channel that runs 

across the plot of land. 

The spiral casing has a simplified design with 

a tapered rectangular cross-section. The rotor 

blades were manufactured using flat sheet metal 

bent and twisted into the required shape. Preliminary 

field testing of the turbine revealed several problems 

during operation. Water was being emptied from 

the forebay tank, resulting in a much lower head than 

the available four meters, and the turbine was not 

producing sufficient power to get the generator up 

to operating voltage. 

Simulation Helps Refine the Design 

Simulations performed on the original rotor geometry 

showed that the maximum turbine efficiency was 

predicted to be approximately 55 percent at 600 rpm 

with a flow rate of 284 liters per second (l/s). However, 

available flow rate at the site was measured to be in 

the range of 180–220 l/s, which was not enough flow 

for the turbine to operate efficiently. From this 

preliminary study, it was concluded that the blade 

angles for the original rotor were incorrect. A new rotor 

with flatter blades and a higher solidity ratio was 

designed using conventional theoretical methods. The 

new rotor geometry was analyzed using ANSYS CFX 

software, and the results predicted a significant reduction 

in the flow rate required to obtain the same power 

output. In addition, the power curve demonstrated an 

improved performance over the speed range with a 

predicted best efficiency for the new rotor of 80 

percent at 800 rpm. 

This project was undertaken to provide power to a farmhouse 

in rural Peru that is used to grind feed for several chicken 

farms owned by the farmer. 

The civil works required for power generation consisted of a 

concrete channel, silt basin, forebay tank and the powerhouse. 

The turbine drives an induction motor as generator (IMAG) 

with controller. The radiator-type ballast loads can be seen 

glowing red in the picture (upper left). 


22 

Preliminary CFD simulations were used to compare the 

original and redesigned rotor geometry. A total pressure 

boundary condition was used for the inlet to simulate a 

constant head of four meters. 

The revised CFD simulations for the redesigned rotor show 

reasonable agreement with the field tests for power output. 

The new rotor was fabricated by a local manufacturer 

in Peru, and field test data was obtained. 

A revised and more accurate CFD model also was 

created, which took into account parameters and 

geometry changes that were not included in the 

preliminary simulations. 

The revised CFD simulations had reasonable 

agreement with the field test results for the power 

output in the low-speed range. However, in the 

high-speed range (above 1200 rpm), the results tend 

to overpredict the power output when compared 

to the field tests. The flow rate through the turbine 

also is underpredicted by the CFD simulations by 

approximately 10 precent. Further investigation is 

currently under way to determine the effect of changes 

to the ANSYS CFX model, including roughness 

effects, leakage losses through the hydrodynamic 

seal and cavitation modeling. 

The new rotor was manufactured locally using flat sheet 

metal bent and twisted into shape and welded to the hub. 

Ongoing Research 

ANSYS CFX software has been used successfully to 

analyze and identify an operational problem with the 

original prototype turbine for the project. Furthermore, 

the software has proved to be a valuable design tool in 

the process of developing and analyzing possible new 

rotor geometries for the turbine. At the time of writing, 

the turbine was producing approximately 4kW of electrical 

power on site at a turbine efficiency of 65 percent. 

Ongoing research aims to further improve the turbine 

design and complement the existing CFD and 

field-test results with detailed laboratory testing. ■ 

This project is funded by a research grant awarded by 

the Leverhulme Trust to Arthur Williams, Ph.D. (principal 

investigator) and Shirley Ashforth-Frost, Ph.D., Nottingham 

Trent University, UK. 

For further information, contact Robert Simpson 

(robert.simpson@ntu.ac.uk) or Arthur Williams 

(arthur.williams@ntu.ac.uk) of Nottingham Trent University. 

Visualization of the velocity vectors at the 

blade mid-span The location fluid volume for the ANSYS CFX simulation was 

separated into four domains: the spiral casing, guide 

vanes, rotor passage and draft tube. 


Guest Commentary 

Integrating CAD and CAE to 

Enable Simulation-Driven Design 

23 

Lack of knowledge capture and re-use holds 

many companies back from gaining the full 

benefits of analysis. 

By Don Brown, Chairman 

Collaborative Product Development 

Associates, U.S.A. 

The explosion of computational 

capacity, now at rock bottom 

prices, will turn engineering 

simulation into an everyday 

tool for all engineers and 

designers across the full 

product development process. 

In such a paradigm shift, CAE 

begins up front with conceptual 

design, engineers perform 

much of their own simulation 

and analytical results drive 

design decisions. Simulation 

experts determine the right process, analysis assumptions 

and check-points to validate results — but do 

not directly execute analysis work. 

What’s holding us back from integrating CAD 

and CAE to enable simulation-driven design? 

Our Design/Simulation Council addresses these 

challenges with a proposed standard framework 

to integrate and optimize the divergent specialist 

activities that fragment design and simulation. A core 

problem relates to lack of knowledge capture and 

re-use regarding simulation. 

Some forward-thinking companies are making 

significant headway in leveraging the knowledge of 

expert specialists in their simulation-driven design 

efforts. Several initiatives rely on an abstract model 

representing analysis work that can be performed 

across similar parts, at all stages of product development 

and across all analysis domains. The model 

includes three main types of information: 

■ Input for the early concept phase covering 

performance requirements and functional 

specifications 

■ Company rules and practices, product 

identification, context of the analysis and 

engineering knowledge or constraints 

that apply 

■ Analysis-related information as a function 

of part and product type that includes 

the part or system definition, geometry, 

assumptions, loads, boundary conditions 

and materials data 

The abstract model is used as a basis for creating a 

specific physical model for analysis. Mesh generation 

and formatting then translate the physical model into an 

analysis execution model for a particular solver. 

Broad implementation of such approaches 

involves a transformation for product development. 

Considerable data management is required to store 

expert knowledge and data models. CAE solutions 

must be architected to leverage this knowledge. Most 

important, organizational changes must meet the needs 

for cross-functional collaboration to integrate design 

and analysis. 

Leading-edge companies, including Airbus, 

Visteon, Whirlpool and John Deere, successfully utilize 

such an approach. At Visteon, the abstract model drives 

all automotive air-handling systems across both 

CAD and CAE. The abstract model is defined by 15 

components, 12 classes and 40 attributes. Airbus 

is standardizing structural analysis across all sites and 

disciplines by automatically generating data needed for 

a particular analysis code from a CAE data model that 

contains analysis abstract models, rules, relationships 

and other information. For example, the shape and 

dimension of each rib in a wing can be defined from a 

set of design rules and constraints, and models may 

apply to all frames of all aircraft based on particular 

plane geometry, loading conditions and materials. 

Today, as in the past, simulation technology too 

often is used only as a forensic tool for post-mortem 

checks, validation and troubleshooting after the fact, 

when the worst of the damage already has been done. 

Too many critical product development decisions are 

made based on assumptions and guesses rather than 

on engineering analysis, even though the tools are 

readily available. Simulation should be applied up front 

to avoid problems in the first place. ■ 

Collaborative Product Development Associates 

(www.cpd-associates.com) provides in-depth information 

for assessing technology, business goals and 

implementation road maps for engineering and 

manufacturing. The firm hosts a variety of events and 

engages in programs for critical analysis of decision 

trade-offs regarding design creation and validation, 

design/simulation council, PLM integration/product 

definition and product value management. 



24 

From the collection of 

Jean-Pierre Lauwers. 

CFD Simulation Recreates 

Aviation History 

Researchers used ANSYS CFX software to study the 1906 flight 

of Alberto Santos-Dumont’s wood and silk aircraft, credited as 

the first officially recognized heavier-than-air flight in Europe. 

By Leonardo O. Bitencourt, Aeronautical Engineering, ESSS, Florianópolis, Brazil 

Ramon Morais de Freitas, Instituto Nacional de Pesquisas Espaciais 

Grégori Pogorzelski, Aeronautical Engineering, Instituto Tecnológico de Aeronautica 

João L. F. Azevedo, Senior Researcher, Instituto de Aeronáutica e Espaço 

Aviation pioneer Alberto Santos-Dumont 

From the collection of Jean-Pierre Lauwers. 

A native of Brazil, Alberto Santos-Dumont was a 

genius obsessed with the concept of flight. A hundred 

years ago, he designed and built a plane from pine 

and bamboo poles covered with Japanese silk in 

a complex biplane, boxkite-like configuration. For 

flight testing, he attached the aircraft to his latest 

dirigible, the Number 14, and the plane became 

known thereafter as the 14-Bis. 

On October 23, 1906, at the Bagatelli Field in 

Paris, Santos-Dumont flew his aircraft 200 feet and 

won the coveted Deutsch-Archdeacon Prize, which 

was created to encourage the growth of aviation. The 

flight was witnessed by officials from what would 

become the Federation Aeronautique Internationale, 

and Santos-Dumont was credited with making the first 

heavier-than-air powered flight in Europe. 


25 

Geometry of the 14-Bis 

Meshing the 14-Bis using ANSYS ICEM CFD software 

To commemorate this milestone in the history of 

aviation, a group of students in Brazil, assisted by 

Engineering Simulation and Scientific Software (ESSS, 

the ANSYS distributor in South America), established 

the CFD 14-Bis Project to celebrate the historic 

occasion through advanced computational fluid 

dynamics techniques. ANSYS CFX software was 

chosen to analyze and understand airflow around 

the plane’s surface. 

A CAD model was developed using historic 

pictures, plans and discussion. Due to the model’s 

complex geometry, the students meshed surfaces 

using hexahedral elements and represented volumes 

with a tetra/prism mesh. ANSYS ICEM CFD software 

was used to create both high-quality surface and 

volumetric meshes. 

Some conclusions can be drawn from the 

ANSYS CFX results. In his first attempt, Santos- 

Dumont used 24 hp nominal power and failed. In the 

second and successful attempt, he increased the 

nominal power to 50 hp. By analyzing drag and lift as 

well as engine thrust, the possible angle-of-attack and 

flight speed values could be estimated: Approximately 

five degrees and the range of 12 to 14 m/s are 

the predicted flight conditions. These values are 

higher than the speed of 11 m/s normally quoted 

in describing the flight. 

As this value is a ground-related speed, the 

possible discrepancy could be due to the presence of 

wind or ground effects during the centennial flight. 

This last factor currently is being studied. Aspects 

related to aircraft stability still are under investigation, 

but preliminary results indicate that the airplane was 

stable even though small variations in the center-ofgravity 

position could make the airplane dangerously 

approach unstable behavior. The simulation gave 

researchers insight into the airflow and dynamics of 

the plane as well as the genius and daring of the 

aviation pioneer Alberto Santos-Dumont. 

The authors wish to thank Professor Paulo Greco from Escola 

de Engenharia de São Carlos, Universidade de São Paulo, 

who provided the geometrical CAD model, and Marcus Reis 

from ESSS, who provided support and licenses for all the 

software used. 

Flow visualization using streamlines 

Lift dependence with flight velocity 

Qualitative analysis of velocity 



26 

Weight-Optimized Design 

of a Commercial Truck Front 

Suspension Component 

Engineers at Dana Corporation use topology optimization features 

of ANSYS Mechanical software to reduce upper control arm weight 

by 25 percent while maintaining required stiffness and strength. 

Headquartered in Toledo, Ohio, Dana Corporation is 

a leading supplier of parts and assemblies to the 

automotive industry. The company designs and 

manufactures a wide range of products for every 

major vehicle producer in the world and has twice 

received the Malcolm Baldrige National Quality 

Award, which recognizes U.S. businesses that 

demonstrate outstanding quality and performance. 

Dana is focused on being an essential partner to 

automotive, commercial and off-highway vehicle 

companies, which collectively produce more than 

60 million vehicles annually. 

Dana’s Commercial Vehicle Systems Group 

specializes in development of front-steer, rear-drive, 

trailer and auxiliary axles; driveshafts; steering shafts; 

suspensions; and related systems, modules and 

services for the world’s commercial vehicle market. 

Dating back to the company’s beginnings in 1904, 

Dana products have helped drive history’s greatest 

vehicles, from the Model T and World War II-era army 

vehicles to London taxicabs, 18-wheel rigs, giant 

earth-moving machines and cars on the NASCAR 

racing circuit. Building on this foundation of 

Designed by Dana Corporation for 

commercial vehicles, the upper 

control arm (highlighted) is a 

critical component in vehicle 

front suspension systems. 

(Dana patents pending.) 


27 

Starting with an initial mesh (left), the ANSYS topology optimization routine automatically eliminates elements with stiffness below 

a specified threshold (right). The result is an analysis model consisting only of the elements needed to maintain the required stiffness 

with minimal material. (Patent-pending design) 

experience, Dana continues its commitment to quality 

and innovation in advancing the science of mobility for 

the benefit of its broad global customer base. 

The Drive for Lighter Suspensions 

Design of suspension systems and other assemblies 

for heavy trucks is a formidable task due to heavy 

loads, harsh environments and long-life requirements. 

Historically, components tended to be over-designed 

heavy structures to meet these reliability requirements. 

But in today’s economy, the weight of commercial 

trucks and its impact on vehicle cost, ride and fuel 

economy are of significant concern for both truck 

manufacturers and end users. 

Lighter, well-designed suspensions provide 

better ride quality, lower initial cost, increased fuel 

economy and greater truck payloads. The challenge is 

to design these parts with minimal material yet 

still maintain adequate strength and stiffness — all 

while meeting tight budgets and product launch 

schedules that rule out building and testing numerous 

hardware prototypes. 

Working with Topology Optimization 

Dana Commercial Vehicle engineers use topology 

optimization features of ANSYS Mechanical software 

to optimize component weight as part of the 

product design process. The method begins by 

determining loads from multibody simulation. Then an 

initial rough solid model is constructed to fill the 

maximum available space envelope allowed for the 

component. Next, a finite-element mesh is developed, 

and the ANSYS topology optimization routine 

automatically eliminates elements with stiffness below 

a specified threshold. 

The result is an analysis model consisting of only 

those elements needed to maintain the required stiffness 

of the component with minimal material. This topologyoptimized 

model then is overlaid on the solid model to 

guide engineers in completing the detailed design of 

the weight-optimized part. 

Key Part of Product Development 

Because weight reduction is a critical issue, this 

optimization approach is used extensively with 

considerable success at Dana. In the development of 

an upper control arm for the front suspension of a 

commercial truck, for example, engineers reduced 

part weight by 25 percent while maintaining required 

stiffness and strength. 

The process was completed in less than a day, 

compared to weeks otherwise needed for trial-anderror 

iterations on expensive physical prototypes. 

Moreover, the optimization guided the design in a 

direction that was not intuitively obvious and provided 

engineers with greater understanding of component 

behavior and stiffness transfer paths. The approach 

has been standardized as a best practice in the group 

and now is applied readily to optimize the weight of 

most of Dana’s commercial truck components. 

“The topological optimization capabilities of 

ANSYS Mechanical software represent a key part 

of our work in developing well-designed, lightweight 

suspensions and other assemblies that meet the 

stringent requirements of the commercial truck 

industry,” explains Caner Demirdogen, senior principal 

engineer at Dana Corporation Heavy Vehicle 

Technologies and Systems. He notes that the 

optimization approach implemented at Dana enables 

engineers to take advantage of this technology in 

reducing component weight much more quickly and 

cost-effectively than trying to accomplish the same 

goals with physical prototypes. 

According to Demirdogen, “Such techniques 

save considerable time and expense in developing 

refined designs, give us tremendous insight into 

component behavior and are a business requirement 

for effectively designing tomorrow’s innovative 

products in the competitive automotive industry.” ■ 



28 

Developing Construction 

Products with Better Fire 

Performance 

ANSYS tools provide models to accurately simulate 

the complex physics of a building fire. 

By Yulian Spasov, Ph.D., Corus Research Development and Technology, Rotherham, UK 

and Yehuda Sinai, Ph.D., ANSYS Europe Ltd., Abingdon, UK 

Fire performance is an extremely important aspect 

of the innovative new building products being 

developed for the construction market at Corus 

Research Development and Technology (Corus 

RD&T). Although standard furnace tests are conducted 

to test compliance with current fire regulations, Corus 

is taking this a step further by using simulation and 

virtual testing to study the behavior of new 

products under conditions that accurately represent 

real building fires. 

ANSYS CFX software was chosen as the CFD 

tool in this virtual testing because of its reputation for 

modeling combustion, radiation and buoyant flows, 

and because Corus has a long tradition of using the 

software. A first step toward developing reliable 

simulation practices has been to validate the software 

and modeling capabilities for specific situations 

against available experimental data. 

Simulating Fire Tests 

In 1993, the Fire Research Station of the Building 

Research Establishment (BRE), in collaboration with 

British Steel Technical, Swinden Laboratories (now 

Corus RD&T) conducted nine fully developed 

fire tests in a large compartment in the BRE 

Cardington Laboratory. The photographic material and 

experimental data presented here are extracted 

from referenced documents. The fire load consisted 

of 33 dry wooden cribs located on the floor of 

the compartment. The ventilation opening was 

obstructed by a column, and all cribs were set on 

fire simultaneously. The experiment lasted three 

hours, and the fire load was 20 kg/m 2 of dry timber, 

which was completely burned by the end of the 

experiment. Temperature, velocity, radiation intensities 

and major species concentration were measured at 

selected locations. The weight of several cribs also 

was monitored to estimate the actual crib burning rate. 

Experimental setup of dry wooden cribs in the fire 

test compartment 

By validating simulation results with an experimental fire, Corus 

is confident in using ANSYS CFX to assist in improving the fire 

performance of their products. 


29 

Simulation results for temperature 

after 20 minutes (top) and 40 

minutes (bottom) 

Comparison with experimental data. Groups A and B (top left and right) thermocouples are 

located near the ceiling at the back and middle of the compartment, while Group C (bottom 

left and right) thermocouples are located inside the compartment, just behind the column. 

For simulation, ANSYS DesignModeler, ANSYS 

CFX-Mesh, ANSYS ICEM CFD Hexa and ANSYS CFX 

10.0 products were used to build the geometry, fluid 

mesh, solid mesh and simulation model, respectively. 

The model takes advantage of eddy dissipation 

combustion, Monte-Carlo gray radiation and the 

SST turbulence models in ANSYS CFX software. 

Conjugate heat transfer through the solid walls was 

modeled using the generalized grid interface capability 

for “gluing” together the unstructured fluid and 

structured solid meshes. The computational domain 

was extended to include a region outside the 

compartment in order to minimize uncertainties in the 

boundary conditions. The heat-release rate of each 

crib was estimated by interpolation of the available 

data for crib mass loss rate. An inflated mesh was 

used in the near-wall region, and a finer mesh close to 

the cribs. The fluid domain contained 150,000 nodes. 

Predictions Agree with Experimental Data 

Temperature readings were taken in four groups of 

locations. Comparison of the experimental data with 

the predicted temperature shows a good agreement 

for all groups for the duration of the simulation. The 

present results are obtained only using best practices 

for modeling of this type, and no adjustments have 

been made to model parameters in order to obtain 

better agreement with experimental data. 

Building fires involve complex physics, and their 

modeling requires accurate combustion, radiation 

and turbulence models. The model within ANSYS 

CFX software provided results that are accurate both 

spatially and temporally. The intuitive nature of the 

user interface, the embedded parametric capabilities 

and the reliability of the available physical models 

showed that ANSYS CFX software is an invaluable 

tool that Corus can use to enhance the fire 

performance of its products. Demonstrating the fire 

performance of whole modular compartments built 

with Corus products would be almost impossible to 

do experimentally. Corus now is able to use the 

ANSYS CFX model with confidence in situations in 

which experimental data is not available or would be 

too expensive and time-consuming to obtain by 

means of physical models. ■ 

References 

B.R. Kirby, D.E. Wainman, L.N. Tomlinson, T.R. Kay, B.N. 

Peacock, “Natural Fires in Large Scale Compartments,” a 

British Steel Technical, Fire Research Station collaborative 

project, 1994. 

GME Cooke, “Tests to Determine the Behaviour of Fully 

Developed Natural Fires in a Large Compartment,” Fire 

Note 4, Building Research Establishment Ltd., Fire 

Research Station, 1994. 



30 

The ANSYS Workbench environment allows for remote 

solutions, letting a high-performance computer cluster 

accelerate work transparently. 

Bringing High-Performance 

Computing to the Mainstream 

Microsoft ® Windows ® Compute Cluster Server lets engineers and 

analysts easily deploy, operate and manage workstation networks 

that, until now, only IT professionals could set up. 

By Kyril Faenov 

Director, High Performance Computing Group 

Microsoft Corporation, U.S.A. 

Traditionally, high-performance computing (HPC) 

has been used primarily by those lucky enough to 

have massive endowments or grants, with access 

to time on the supercomputer strictly rationed. 

HPC generally meant a single, large, symmetric 

multiprocessing (SMP) or vector supercomputer and 

a budget to match. 

Solving cutting-edge problems in science, 

engineering and business has always demanded 

capabilities beyond those of even the fastest workstations. 

Market pressures demand an accelerated 

product development cycle and reduced time-toinsight. 

The use of commodity servers in compute 

clusters now brings the power of supercomputing to 

the workgroup or even desktop level. 


In 1991, the cost of a 10 Gflop Cray supercomputer 

was $40 million; the computers were available 

only in government labs, very large corporations or 

academic research institutions. Today, that same 10 

Gflop computing power is available in a four-node 

compute cluster that can be bought off-the-shelf 

for $4,000. 

This proliferation of HPC has an enormous effect 

on research and industry, making it possible to solve 

problems that simply couldn’t be attempted before. 

But it also presents challenges for both vendors and 

consumers of HPC. 

Challenges of Compute Clusters 

When HPC was a single, large integrated supercomputer, 

the researcher didn’t have to worry about how 

to deploy or manage the system — that was the job of 

(usually several) dedicated information technology (IT) 

professionals, with accompanying salaries and costs. 

But as we move to compute clusters of commodity 

servers, especially at the workgroup level, the 

challenge is to provide an installation and management 

experience that doesn’t distract from the reason 

for the cluster in the first place — without requiring 

major IT resources that would change both the 

economics and the immediacy of the interaction that 

are driving this proliferation. 

Another area of concern is security. When HPC 

was a single supercomputer with carefully controlled 

and allocated access, security was inherent in the 

process: The system was physically isolated and had 

no direct connection to corporate or other networks. 

Each researcher’s job ran as a discrete, self-contained 

batch job. Today’s HPC compute cluster often is 

directly connected to the corporate network, and it is 

shared across a diverse group of scientists, engineers 

or analysts. Individual jobs may use only a portion of 

the cluster at any one point, with other jobs running 

simultaneously on other nodes in the cluster. Security 

must be built in to the overall HPC environment to 

protect the integrity of the cluster and the individual 

jobs that run on it, as well as the corporate network on 

which it resides. 

31 

Networking 

Windows CCS 2003 has a four-step wizard that easily configures networking, deploys compute nodes without IT intervention 

and manages cluster users. 



32 

Accelerating Work Transparently 

The biggest benefit of an HPC compute cluster is 

availability. Compute clusters consisting of commodity 

servers have driven down the price per Gflop to the 

level at which anyone can reasonably afford his 

own HPC, and results are available faster and more 

interactively. By taking advantage of applications 

such as Distributed ANSYS, users can perform their 

simulations quicker, get more people involved in the 

simulation and reach product decisions faster. 

Windows 

The familiar Windows infrastructure is used by CCS 2003 in its 

Microsoft Management Console for managing compute clusters. 

ANSYS, Inc. has embraced the client–server 

compute model in the ANSYS Workbench environment 

working with Distributed ANSYS. This enables 

users to focus on performing simulations and allows 

for remote solutions in the process, thereby letting 

the advanced computing power of an HPC cluster 

accelerate the work transparently. 

Role of CCS 2003 

Microsoft ® Windows ® Compute Cluster Server (CCS) 

2003 provides a complete HPC cluster solution that: 

■ Easily installs and deploys on 

commodity servers 

■ Is highly secure and robust 

■ Easily integrates into existing data 

environments 

■ Leverages existing IT infrastructure 

■ Scales from personal clusters to TOP500 

clusters transparently 

■ Brings HPC mainstream 

By integrating directly with Microsoft Active 

Directory ® , CCS 2003 leverages the existing IT 

infrastructure, including Group Policy, to provide a 

secure cluster environment. A simple four-step wizard 

configures the networking, installs and configures the 

remote installation service (RIS) to deploy compute 

nodes from bare metal without IT intervention, 

and manages the cluster’s users. Node deployment is 

simple and painless, making it possible to create a 

prototype solution on a small cluster and then scale it 

up as needed. 

CCS 2003 leverages the familiar Windows 

management infrastructure as well, using Microsoft 

Management Console (MMC) 3.0 for cluster 

management while supporting Microsoft Operations 

Manager (MOM) for monitoring and management, 

and supporting Microsoft Systems Management 

Server (SMS) for node updates. 

CCS 2003 includes Microsoft Message Passing 

Interface (MS-MPI), a secure and fully compatible 

interface based on the Argonne National Laboratory 

MPICH2 reference implementation to simplify 

migration of existing code and integration with existing 

HPC environments. 

The new Job Scheduler supports both a full 

command-line job management and a graphical 

interface to simplify job submission and monitoring. 

Job scheduling is part of the end-to-end security 

of CCS 2003, which leverages Active Directory to 

allow jobs to run with domain user credentials while 

protecting those credentials from other jobs in 

the queue. 

Finally, CCS 2003 leverages Microsoft ® Visual 

Studio ® 2005 to provide a familiar, integrated development 

environment that supports remote parallel 

debugging on the cluster, allowing developers to 

quickly test and debug their code. The rich Visual 

Studio environment gives application developers the 

tools and language choices they need. 

Summary 

The wide availability of compute clusters running 

on commodity hardware is driving the proliferation 

of high-performance computing. Microsoft Windows 

Compute Cluster Server 2003, working with 

applications such as Distributed ANSYS, provides 

a high-performance computing platform that is 

simple to deploy, operate and integrate with existing 

infrastructure and tools. ■ 

For More Information 

■ Microsoft HPC public Web site: www.microsoft.com/hpc 

■ CCS 2003 community site: www.windowshpc.net/default.aspx 

■ Windows Server x64 information: www.microsoft.com/x64 

■ Windows Server System information: www.microsoft.com/wss 

■ ANSYS Workbench information: www.ansys.com/products/ 

workbench.asp 

■ Distributed ANSYS information: 

www.ansys.com/products/parallel.asp 


Tech File 

Running Solutions 

from Macros 

These handy do-it-yourself files can 

be real time-savers, both now and 

for future projects. 

33 

By John Crawford 

Consulting Analyst 

It’s interesting how the way we 

use ANSYS evolves as we 

become more familiar with the 

program. Most people begin by 

using the menus for modeling 

building and entering all the information needed to run 

an analysis. As they gain experience, their use of 

menus gradually is supplemented by entering commands 

via the command line because it allows them to work 

more quickly. With more familiarity, it’s an easy transition 

to use our knowledge of commands to write 

macros and other input files in ANSYS Parametric 

Design Language (APDL). Doing this taps into the real 

power of ANSYS technology, whether it’s a macro for a 

single specific application or one that can be used over 

and over again. 

One of the practices I’ve used over the years is to 

run almost all my solutions with a macro or input file. 

Macros and input files are exactly the same; they differ 

only in how they are executed. A macro has a .mac 

extension and can be executed by typing the macro 

name in the command line. An input file contains the 

same data but doesn’t have the .mac extension, so you 

need to use the /INPUT command to tell ANSYS to 

input the file and execute the commands that reside 

within it. 

Well Worth the Effort 

Regardless of whether you use a macro or an input file 

to run a solution, the benefits of working in this manner 

make it worth the effort to write them. When doing an 

analysis, I usually build the model and get everything 

set up and ready to go, with the exception of most of 

the loads and solution settings. I may include some of 

the boundary conditions that I don’t expect to change 

in the model, and I write a macro that contains other 

loads and solution settings for each load step that will 

be run. I usually define loads as parameters at the top 

of the macro so they can be changed easily by myself 

or anyone else who might use the macro to rerun the 

analysis at a later date. 

The solution macro usually begins by resuming 

the startup model; then it assigns values to parameters 

that I want to use in the solution. When doing a model 

analysis, I might define the frequency range and number 

of frequencies to solve for as parameters and then use 

these to control how the solution is performed. Or I 

might use a parameter to tell ANSYS whether the 

excitation for a PSD analysis is in the X, Y or Z direction. 

The macro then uses these parameters as it 

progresses through the application of loads and 

solution settings and runs the solution for each load 

step or substep. I always include comments in the 

macro that explain what is being done and why. 

Saving Time and Trouble 

Writing solution macros may sound like a lot of 

unnecessary extra work, but, for all but the simplest 

solutions, it’s a tremendous productivity enhancer. 

Here are just a few reasons why I use solution macros 

in almost all my work: 

■ It gives me a history of the loads and solution 

steps to which I can refer when reviewing 

results. Sometimes it’s difficult to remember 

what loads or options I applied for a specific 

load step or substep. Having them listed in a 

macro removes all uncertainty regarding how 

the solution was obtained. 

■ Rather than starting ANSYS and resuming a 

model, I can refer to the macro when someone 

asks about the loads, the number of load 

steps and other solution controls. 

■ I can revisit an analysis later and rerun it in an 

efficient and consistent manner. This is useful 

when I need to run different loads and want to 

duplicate the earlier solution as a starting 

point. 


Tech File 

34 

■ 

■ 

■ 

■ 

■ 

■ 

I can easily vary solution settings (contact 

element stiffness, convergence criteria, 

substep size, etc.) to see what effect they 

have on the analysis. In this manner, every 

solution begins from the same starting point. 

The macro can automatically calculate settings 

that are unique to a specific solution. For 

example, if I want to run a series of harmonic 

analyses that vary from one frequency to 

another, I can have the macro calculate alpha 

and/or beta damping for each frequency. 

It greatly reduces the possibility for errors 

because I have a document that confirms 

what I did to get the latest solution. 

The macro can be listed in the appendix 

of a report so readers know exactly what 

was done. 

The macro is easily shared with others who 

wish to do similar solutions. 

I can refer to the macro the next time I do 

a similar type of solution and use it as a 

foundation for future work. 

Benefits of a Macro Library 

While all the above reasons make macros well worth 

the time needed to write them, I think the last reason 

benefits me the most. I have a library of solution 

macros that cover a wide range of analyses done in 

the past, and I frequently refer to these when tackling 

similar projects. Here is an example. 

Several years ago I did a transient analysis of a 

pressure wave striking a panel to determine how the 

stress wave propagates through the panel. This was a 

fairly complicated analysis with very small time increments 

and several thousand load steps. A few years 

later, I was asked to model a sphere impacting a 

machined part to see how quickly the stress waves 

moved through the part, what the alternating stresses 

were, and how much reflection and damping were 

taking place. Rather than re-invent the wheel, I pulled 

up the macro from my earlier analysis to refresh my 

memory of how I had previously solved this type of 

problem, and I used it as the basis for the more 

complicated analysis I was now beginning to work on. 

This enabled me to work more quickly and avoid some 

of the pitfalls I had worked through previously. Once I 

had the new macro running, I could vary contact 

element stiffness, number and duration of time steps, 

and many other things that I needed to adjust to 

ensure that the results were accurate and useful. 

I’ve used solution macros for quite a while and 

now have a substantial library of them. The next time 

I want to do a power spectral density analysis, I have a 

macro that I can refer to that will help me do it again. 

Single point response spectrum? No problem. Transient 

dynamic analysis? I have macros that will help 

me with that. Modal cyclic symmetry? I have a couple 

of those macros. An axisymmetric transient heat transfer 

solution that has the results applied to a 3-D structural 

analysis? That’s in my library as well. Superelement 

generation, use and expansion passes used in several 

different types of analyses? I have all of these. 

Whether I last ran a specific type of analysis last 

week or five years ago doesn’t matter. I can review 

the solution macro to retrieve the insight and 

understanding I had at that time and quickly perform 

the analysis that I want to run today. Because 

ANSYS emphasizes upward compatibility in new 

releases, the commands that worked in my earlier 

analysis will work in my new analysis, too. 

Leveraging Knowledge of ANSYS Tools 

Solution macros not only benefit me, but they also 

help my customers. When I finish an analysis, I turn 

over the model and the macros I used to run the 

solution and perform the post-processing. This allows 

the customer to duplicate the results at a later date or 

to make changes to the loads and run a new solution. 

By putting the loads at the top of the macro as 

parameters and taking the time to thoroughly make 

comments on what they are and how they are used, 

the customer is able to change the parameters and 

run a new solution without any special understanding 

of APDL or ANSYS. This allows the customer to 

leverage my knowledge of ANSYS to his benefit, so 

he can run additional solutions without my being 

directly involved. 

I didn’t use solution macros on a regular basis 

until I had been an ANSYS software user for quite 

a while. But when I began writing and using them, 

I discovered that it was a worthwhile investment in 

time and effort that has paid off over and over again. 

Maybe it will pay off for you as well. ■ 



Working with 

Coupled-Field Elements 

35 

PLANE223, SOLID226 and SOLID227 elements readily handle 

multiphysics problems coupled via material response. 

By Sheldon Imaoka / Technical Support Engineer / ANSYS, Inc. 

When multiple physics problems are coupled 

via material response, the physics need to be 

solved simultaneously. This is a typical application 

of the use of 22x coupled-field elements, which 

have multiple degrees-of-freedom (DOF) and can 

support piezoelectric, piezoresistive, thermoelastic 

and thermoelectric materials. 

Piezoelectricity 

In piezoelectric materials, structural and electric fields 

are coupled so that an applied voltage generates a 

strain (and vice versa). Consequently, piezoelectric 

ceramics are used as transducers to convert electrical 

energy to a mechanical response or as sensors to convert 

mechanical energy to an electrical signal. 

Mechanical stress {T} and strain {S} are related to 

electric displacement {D} and electric field {E} via the 

following constitutive equations: 

Here, [s E ] is the compliance matrix evaluated at 

constant electric field, [ε T ] is the permittivity matrix 

evaluated at constant stress and [d] is the piezoelectric 

matrix relating strain to electric field. 

The above relationship provides a basis for the 

FEA piezoelectric matrix equations: 

■ 

■ 

[K V ] is the (anisotropic) permittivity matrix with 

permittivity values evaluated at constant strain 

[ε S ] or constant stress [ε T ]. 

[C u ] is the structural damping matrix, whereas 

[C V ] represents dielectric losses. 

Issues to consider: Since coupling is via the 

coefficient matrix, a single iteration is required for 

calculating coupled effects. Elements support nonlinear 

static, modal, harmonic response and transient 

analyses. The dielectric loss tangent tanδ can be input 

via MP,LSST, which is part of [C V ]. Manufacturers’ data 

typically have mechanical vectors in the form {x, y, z, yz, 

xz, xy}, whereas ANSYS requires the input to be {x, y, z, 

xy, yz, xz} — so the 4/5/6 terms need to be rearranged. 

Piezoresistivity 

For piezoresistive materials, an applied mechanical 

stress or strain causes a change in the material’s 

resistivity for use as sensors, for example, in which a 

mechanical load affects the electrical signal. 

The electrical resistivity [ρ] is related to stress 

as follows: 

in which [ρo] is the input (nominal) resistivity and [π] is 

the piezoresistive stress matrix. Alternatively, the 

piezoresistive strain matrix [m] may be input instead, 

relating relative change in resistivity to strains. 

The resulting matrix equations are: 

Description of terms: 

■ 

■ 

[K Z ] contains the piezoelectric effect, and the 

piezoelectric constants can be input as either 

[d] form (strain/electric field) or [e] form 

(stress/electric field). 

[K u ] contains (anisotropic) stiffness 

coefficients, and these are either compliance 

[s E ] or stiffness [c E ] coefficients. 


■ 

■ 

[K V ] is the (orthotropic) electrical conductivity 

matrix, which includes piezoresistive effects 

as described above. 

[K u ] contains the (anisotropic) stiffness 

coefficients. 



36 

Issues to consider: Coupling is in the coefficient 

matrix, but resistivity is based on calculated stress or 

strain, so multiple iterations are required for calculating 

coupled effects. Elements support nonlinear static and 

full transient analyses. The change in resistivities can 

be measured by a Wheatstone bridge configuration, 

since this is how piezoresistive materials usually are 

arranged. Input of permittivity allows for definition of 

[C V ] to account for dielectric effects. 

Thermoelectricity 

In thermal–electric applications, two types of coupling 

are present. Joule heating is an irreversible process 

occurring when current flows through material with 

electrical resistance, proportional to the current 

squared and independent of the current direction: 

Thermoelectricity consists of the reversible 

Seebeck, Peltier and Thomson effects. 

The Seebeck effect, defined by the coefficient α, 

relates a temperature gradient with a potential 

difference. An example application is MEMS power 

generation converting heat to electrical power: 


■ 

■ 

[K VT ] is the Seebeck coefficient coupling matrix. 

Joule heating {Q j } and the Peltier effect {Q p } are 

included in the load vector. 

The Thomson effect is not explicitly included 

above, since it is accounted for when temperaturedependent 

Seebeck coefficients exist. 

Issues to consider: Since Joule heating and 

Peltier effect are accounted for by load-vector 

coupling, thermal–electric analyses are iterative in 

nature. Material behavior supports nonlinear static 

and transient analyses. Absolute temperature needs 

to be defined via TOFFST. 

Thermoelasticity 

Thermal–stress analyses are commonplace, in which 

the temperature field is calculated and imposed as a 

load vector on the structural model. However, the 

piezocaloric effect (thermoelastic damping) also can be 

modeled with 22x coupled-field elements for dynamic 

applications. The constitutive relations are: 

The Peltier effect, noted by π, is the reverse 

condition in which a current causes a heat differential, 

and the direction of the current determines whether 

heat is removed or input. Typical examples are thermoelectric 

coolers: 

in which {α} is the coefficient of thermal expansion, S is 

entropy density and To is the absolute temperature. 

The combined system of equations is expressed in 

matrix form: 

The Thomson effect, described by the coefficient 

µ, illustrates what occurs when a current flows through 

a material with a temperature gradient: 

Seebeck, Peltier and Thomson coefficients 

are related using absolute temperature To, so only 

Seebeck coefficients need to be defined: 

Thermal–electric equations are incorporated into 

the FE matrices as follows: 


■ 

[K uT ] is the thermoelastic stiffness matrix 

(thermal expansion term) while [C Tu ] is the 

thermoelastic damping matrix. 

Issues to consider: The system of equations is 

unsymmetric, although by having it matrix-coupled, the 

effects are considered in a single iteration. Nonlinear 

static, full transient or harmonic response analyses are 

available. The piezocaloric term (also known as 

thermoelastic damping because of the coupling of the 

energy equation) is present only for dynamic (harmonic 

or transient) analyses and does not act like structural or 

viscous damping by always lowering the resonant 

frequencies. Coefficient of thermal expansion provides 

the coupling response for both [K uT ] and [C uT ] terms. 

A temperature offset via TOFFST is required, with 

the reference temperature designating strain-free 

temperature. ■ 

Contact the author at sheldon.imaoka@ansys.com for the 

entire paper from which this article was excerpted.

63792 Solutions Fall 06-FINAL, page 1-40 @ Normalize - MESco

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