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stadium, and the distance from the building to the outlet is 15H. Therefore, the requirements by Franke et al. [16]and Tominaga et al. [17] are satisfied.4.2. Computational gridA high grid quality in the immediate vicinity of the stadium is very important for the accurate simulation ofthe interaction of the ABL wind flow with the indoor natural ventilation. However, the generation of such ahigh-quality grid for the complex stadium geometry is not straightforward, due to both the complexity of thestadium and the large differences between the smallest (0.02 m) and the largest (2,900 m) length scales in thecomputational domain. Standard automatic or semi-automatic generation of an unstructured grid does notprovide sufficient control of local grid resolution, grid stretching, control volume skewness and aspect ratio. VanHooff and Blocken [9] described the grid-generation procedure used to simultaneously generate the geometryand the computational grid of the stadium. It consists of a series of grid extrusion operations that allows fullcontrol over the grid quality, size and resolution. The resulting hybrid grid contains 5.6 x 10 6 prismatic andhexahedral cells. An overall view of the grid from northwest is shown in Fig. 7. Figure 8 shows thecomputational grid from inside the stadium; Figure 8b shows the grid in the vicinity of one of the largeventilation openings (gates) in the corner of the stadium. A grid-sensitivity analysis was performed using threegrids with different grid resolutions; a coarse grid with 3.0 million cells (Fig. 7b), a middle grid with 5.6 millioncells (Fig. 7c) and a fine grid with 9.2 million cells (Fig. 7d). The minimum volumes for the three grids are 4.3 x10 -5 m 3 , 3.5 x 10 -5 m 3 and 2.0 x 10 -5 m 3 . A grid-sensitivity analysis is best performed by comparing relevantparameters at relevant locations. In this paper, the interaction of the ABL wind flow with the interior airflowimportant. Therefore, the most relevant locations are the ventilation openings, and a relevant parameter is thevolume flow rate through these openings. Since the openings in the corners of the stadium are the mostimportant ventilation openings when the roof is closed, the three grids are therefore compared based on thenormalised volume flow rates through these four gates:14QQi; coarse i;middleQi 1 total ; middle100%(3)24Qi; middle i;fineQQi 1 total;fine100%where Q i;coarse , Q i;middle and Q i;fine are the volume flow rates (m 3 /s) through gate i for the coarse, middle and finegrid, respectively. The calculated value of δ 1 is 4.7% and of δ 2 is 2.0%. The results obtained with the middle gridshow no large discrepancies with the results of the finer one. The results obtained with the coarse grid showsomewhat larger deviations from the middle grid. Therefore, the middle grid was selected. Note that the specificgrid generation procedure for the case of this stadium does not allow the use of a systematic identical refinementfactor throughout the entire domain. As a result, the discretisation errors themselves have not been determined.(4)5. CFD simulations: validation of isothermal wind flow and indoor airflow5.1. Boundary conditionsA logarithmic mean wind speed profile representing a neutral atmospheric boundary layer is imposed with y 0= 0.5 m and a reference wind speed U 10 (at 10 m height) of 5 m/s. The reference wind direction φ ref = 228° fromnorth, which corresponds to the meteorological conditions during the wind velocity measurements. Turbulentkinetic energy k is calculated from I u using k = 1.5(I U U) 2 , assuming isotropic turbulence (σ u = σ v = σ w ). The inletlongitudinal turbulence intensity I U ranges from 30% at pedestrian height (y = 2 m) to 5% at gradient height. Theturbulence dissipation rate is calculated with = (u* ABL )³/( (y+y 0 )), where y is the height coordinate, κ the vonKarman constant (κ = 0.42) and u ABL * the atmospheric boundary layer (ABL) friction velocity related to thelogarithmic mean wind speed profile. The standard wall functions by Launder and Spalding [79] are used withthe sand-grain based roughness modification by Cebeci and Bradshaw [80]. The parameters k S and C S aredetermined from their appropriate relationship with y 0 , which was derived by Blocken et al. [77] for Fluent andCFX. For Fluent 6, up to at least version 6.3, this relationship is given by:kS9.793 yCS0(5)7

Page 8Foreign Language Technology Center’s Newsletter2007 FLTC SurveyBy Pamela SaenzDuring the Winter2007 Semester, the ForeignLanguage Technology Center(FLTC) conducted a surveyof instructors who use FLTCresources for teaching.Approximately one-third ofthe 150 instructors invited totake part in the survey responded.Fifty-five percent of therespondents indicated theyteach language courses, andanother 30 percent indicatedthey teach language as wellas culture and literaturecourses. Of the respondents,FLTC resources are usedmost frequently by Spanishinstructors, followed closelyby French, English as a secondlanguage, and German/Slavic.The services most usedare the mobile audio/videoequipment and instructionaland faculty computer labs.A surprising 41 percent ofour respondents use digitizing,copying, and conversionservices, and 18 percent usethe digital editing suite.Many respondents useBlackboard (76 percent), 20percent use video reserveservices, and the mobilevideo cart is the most popularequipment followed bythe LCD projector with orwithout laptop. The instructionallabs are used primarilyfor accessing Web sites bycomputer, viewing films,CAN8, and PowerPointpresentations.Most of the respondentsindicated that they weresatisfied with the services ofthe FLTC. There were a fewrecommendations for changeindicating a desire for earlieror later hours of operation,universal remote controls,online reservation forms,more and higher-technologyequipment, and workshopsdemonstrating the efficientuse of new technology.One respondent asked fora “mobile” lab which can betaken into the classroom.The FLTC now has two wirelessmobile laptop carts:one with19 Mac laptops andanother with 16 Dell computers.Another request wasmade for placing digital mate-rials and films online. Ourresident systems analyst,Muhammad Faisal, has placedsome movies and clips onlineusing the new streamingmedia server.The FLTC appreciatesthe time and effort takenby instructors to respondto the survey. Read elsewherein the newsletter forinformation about the waysour services are changing tomeet the technology needs oflanguage instructors.iMythology continued from page 1By Jennifer Sheridan Moss“Podcasts offer a newmethod of instructionaldelivery that appeals totoday’s student.”historical and archaeologicalbackground, comparativemythology, and back-stories tosupplement the major worksof literature we read. In class,students discussed the greatworks of Greek mythology,such as Homer and tragedy.Although many people feelthat using technology pandersto students’ lazier side, thiscourse used technology to freethe students to focus on readingoriginal texts and on writingessays. As a result, thiscourse was more challengingthan other versions of mythologythat I have taught, and thestudents were far more engagedwith the material.The process of creatingpodcasts is labor-intensive andexpensive; for this first round,one minute of podcast hastaken approximately one hourto create. I used my FLTCgrant to hire two assistants,one who could help with content,and another who couldcreate the podcast files. Thestaff of the FLTC assisted withthe technology as well. Weran into many snags along theway, as one might expect, butI hope soon to post a podcaston how to make podcasts;this will save time for otherswho want to replicate thisproject.The ideal academic podcastcovers a discrete amountof material in a short broadcast(around five minutes);think more in terms of anNPR story than a documentary.It should contain visualsif applicable; critical vocabularyor formulas can be providedon slides during the podcast.Audio-only podcasts arefine for material without avisual component. Full-lengthclass lectures where soundand lighting quality are likelyto be poor do not lend themselvesto the podcast format.Podcasts offer a newmethod of instructional deliv-ery that appeals to today’sstudent. They do not replace—asfaculty universallyfear—live instruction orreading assignments. Studentscan listen to them asmany times as necessary, andthey can be used at differenttimes of the semester toremind students of facts theymay have forgotten. Podcastscan be recycled from semesterto semester, and caneven be used for differenttypes of classes; for example,I could have Latin studentsstudying Vergil listen to thepodcasts on the Trojan Warrather than spending classtime lecturing. Most importantly,because the studentslove the technology, they arewilling to learn more.FLTCForeign Language Technology Center, 385 Alex Manoogian Hall, Phone: (313) 577-3022906 West Warren Avenue, Detroit, Michigan, 48202 www.langlab.wayne.edu