Unmanned Aircraft Systems Roadmap 2005-2030 - Federation of ...

Unmanned Aircraft Systems Roadmap 2005-2030 - Federation of ... Unmanned Aircraft Systems Roadmap 2005-2030 - Federation of ...

06.01.2013 Views

UAS ROADMAP 2005 recognized today as the prime attribute of an UA when compared to manned aircraft, and endurance is determined largely by the efficiency of the powerplant, propulsion is, with processors, one of the two key UA technologies. Two key propulsion metrics are specific fuel consumption (SFC) for efficiency and specific power (SP) for performance. AFRL’s Versatile Affordable Advanced Turbine Engines (VAATE) program aims to achieve a 10 percent decrease in SFC by 2015, while improving thrust-to-weight (T/W) by 50 percent and lowering engine production and maintenance costs. Reciprocating engines for aircraft generally produce 1 hp per pound of engine weight (746 watts/lb), and today’s fuel cells are approaching this same level, while lithium-ion batteries have about half this SP (See Figure 4.3-1). Fuel cells in particular are expected to show rapid advancement over the coming decade due their increasing use in hybrid automobiles. Heavy fuel engine (HFE) technology has advanced over the last few decades to the point where replacement with internal combustion engines on tactical UA is now practicable. However, further HFE development investment needs to be made to make their use on small UA practicable. Additional investment also needs to be made in turbine technology for a J-UCAS class engine with a high thrust to weight ratio and low SFC. Specific power trends in propulsion and power technology are forecast in Figure 4.3-1 and Table 4.3-1. Recommended Investment Strategy: Focus DoD research on developing diesel reformaters for fuel cell use, enhanced engine durability and time between overhaul, improved specific fuel consumption for enhanced endurance, and alternative propulsive power sources like fuel cells, photovoltaic, and nuclear propulsion systems. 4.3.4 Reliability Aircraft reliability and cost are closely coupled, and unmanned aircraft are widely expected to cost less than their manned counterparts, creating a potential conflict in customer expectations. The expected benefit of lower unit prices may be negated by higher attrition rates due to poorer system reliability. The impact of reliability on UA affordability, availability, and acceptance is described in detail in Appendix H. Figure 4.3-2 illustrates how the mishap rates of larger UA compare to that of representative manned aircraft (F-16 and U-2) after similar numbers of flying hours have been accumulated. Since UA fleets are generally smaller than manned fleets, they have accumulated flying hours at lower rates resulting in slower progress down this curve. As an example, the MQ-1 Predator fleet just reached the 100,000-hour mark in October, 2004, 10 years and 3 months after its first flight, whereas the F-16 reached this same mark in one quarter of that time and the 800,000-hour mark in that same time. However, the Figure shows that the mishap rates of the recent, larger UA track closely with that of the F-16 fleet at a comparable point in its career. Recommended Investment Strategy: See “Recommendations” in Appendix H Page 53

UAS ROADMAP 2005 Turbine Engine Efficiency, % (Solar Cells Only) Hypersonics Scramjets Turboelectric Machinery Rechargeable Batteries 28 25 20 15 10 5 0 Specific Power, hp/lb 30 2.5 2.0 1.5 1.0 0.5 0 NiCd Specific power of gas turbines equals 4 to 10, depending on airspeed Alkaline Alkaline FC VRLA Rotax 914 Motto Guzzi GM NiMH Space Shuttle Solar Cells (Efficiency Only) Silicon Cell Limit Internal Combustion Engines Batteries 1950 1960 1970 1980 1990 2000 2010 2020 2030 GM Li-Poly Li-ion GM GM GM FIGURE 4.3-1. MASS SPECIFIC POWER TRENDS. Fuel Cells TABLE 4.3-1. PROPULSION AND POWER TECHNOLOGY FORECAST. Turbofan, turboprop, Integrated High Performance Turbine Engine Technology (IHPTET) Now 2010 2015 AF Single Engine Scramjet Demo, Mach 4-7, X-43C Multi-engine, Mach 5-7 Integrated Drive Generator on Accessory Drive, Integrated Power Unit – F- 22 Lead Acid, NiCd, in wide use, Lithium Ion under development –(B-2 battery – 1st example) Photovoltaics Silicon based single crystal cells in rigid arrays Fuel Cells Prototypes demonstrated in ground-based assets. Versatile Affordable Advanced Turbine Engines (VAATE-1) Robust Scramjet: broader operating envelope and reusable applications (e.g. turbine-based combined cycles) No AMAD, Electric Propulsive Engine Controls, Vehicle Drag Reduction/Range Extension Lithium Ion batteries in wide use (100-150 WH/kg) Flexible thin films Multi-junction devices – Germanium, Gallium based Production PEM/SO fuel cells available for UA Begin UA integration Page 54 VAATE-II Note: VAATE ends in 2017 Hypersonic cruise missiles could be in use w/in operational commands. Prototype high Mach (8-10) air vehicles possible Enabling electrical power for airborne directed energy weaponry Solid State Lithium batteries initial use (300-400 WH/kg) Concentrator cells and modules technologies (lens, reflectors) Fuel cells size/weight reductions Fuel flexible reformers

UAS ROADMAP <strong>2005</strong><br />

Turbine<br />

Engine<br />

Efficiency, % (Solar Cells Only)<br />

Hypersonics<br />

Scramjets<br />

Turboelectric<br />

Machinery<br />

Rechargeable<br />

Batteries<br />

28<br />

25<br />

20<br />

15<br />

10<br />

5<br />

0<br />

Specific Power, hp/lb<br />

30<br />

2.5<br />

2.0<br />

1.5<br />

1.0<br />

0.5<br />

0<br />

NiCd<br />

Specific power <strong>of</strong> gas turbines<br />

equals 4 to 10, depending on airspeed<br />

Alkaline<br />

Alkaline FC<br />

VRLA<br />

Rotax 914<br />

Motto Guzzi<br />

GM<br />

NiMH<br />

Space Shuttle<br />

Solar Cells<br />

(Efficiency Only)<br />

Silicon Cell Limit<br />

Internal Combustion<br />

Engines<br />

Batteries<br />

1950 1960 1970 1980 1990 2000 2010 2020 <strong>2030</strong><br />

GM<br />

Li-Poly<br />

Li-ion<br />

GM<br />

GM<br />

GM<br />

FIGURE 4.3-1. MASS SPECIFIC POWER TRENDS.<br />

Fuel Cells<br />

TABLE 4.3-1. PROPULSION AND POWER TECHNOLOGY FORECAST.<br />

Turb<strong>of</strong>an, turboprop,<br />

Integrated High<br />

Performance Turbine<br />

Engine Technology<br />

(IHPTET)<br />

Now 2010 2015<br />

AF Single Engine Scramjet<br />

Demo, Mach 4-7, X-43C<br />

Multi-engine, Mach 5-7<br />

Integrated Drive Generator<br />

on Accessory Drive,<br />

Integrated Power Unit – F-<br />

22<br />

Lead Acid, NiCd, in wide<br />

use, Lithium Ion under<br />

development –(B-2 battery<br />

– 1st example)<br />

Photovoltaics Silicon based single crystal<br />

cells in rigid arrays<br />

Fuel Cells Prototypes demonstrated in<br />

ground-based assets.<br />

Versatile Affordable<br />

Advanced Turbine Engines<br />

(VAATE-1)<br />

Robust Scramjet: broader<br />

operating envelope and<br />

reusable applications (e.g.<br />

turbine-based combined<br />

cycles)<br />

No AMAD, Electric<br />

Propulsive Engine Controls,<br />

Vehicle Drag<br />

Reduction/Range Extension<br />

Lithium Ion batteries in wide<br />

use (100-150 WH/kg)<br />

Flexible thin films<br />

Multi-junction devices –<br />

Germanium, Gallium based<br />

Production PEM/SO fuel cells<br />

available for UA<br />

Begin UA integration<br />

Page 54<br />

VAATE-II<br />

Note: VAATE ends in 2017<br />

Hypersonic cruise missiles<br />

could be in use w/in<br />

operational commands.<br />

Prototype high Mach (8-10)<br />

air vehicles possible<br />

Enabling electrical power for<br />

airborne directed energy<br />

weaponry<br />

Solid State Lithium batteries<br />

initial use (300-400 WH/kg)<br />

Concentrator cells and<br />

modules<br />

technologies (lens, reflectors)<br />

Fuel cells size/weight<br />

reductions<br />

Fuel flexible reformers

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!