Airpak_2.0_Tutorial_Guide

Airpak2.0TutorialGuideOfficeVentilationIntroductionPrerequisitesProblemDescriptionStep1:OpenandDefineaNewJobStep2:BuildtheModelStep3:AddRadiationtotheModelStep4:GenerateaMeshStep5:ChecktheFlowRegimeStep5:SavetheModeltoaJobFileStep6:CalculateaSolutionStep7:ExaminetheResultsSummaryReferencesIntroductionThistutorialdemonstrateshowtomodelanofficesharedbytwopeopleworkingatcomputers,usingAirpak.Inthistutorialyouwilllearnhowto:OpenanewjobIncludeeffectsofrelativehumiditydistributioninthesimulationCreateblocks,openings,vents,partitions,andwallsModeltheeffectsofradiationChangethenumberofsolveriterationsCalculateasolutionExaminecontoursandvectorsonobjectfacesandcross-sectionsofthemodelTraceparticlestreamsfromairinletsExaminethecomfortlevelintheroombycalculatingthepredictedmeanvote(PMV)andpredictedpercentagedissatisfied(PPD)PrerequisitesThistutorialassumesthatyouhavelittleexperiencewithAirpak,butthatyouaregenerallyfamiliarwiththeinterface.Ifyouarenot,pleasereviewthesamplesessioninChapter1oftheUser'sGuide.ProblemDescriptionTheofficeispartitionedintotwosections,eachcontainingonepersonworkingatacomputer,asshowninFigure1.1.Theofficealsoincludessixfluorescentlights,abaseboardheater,aninletdiffuser,aventilationreturn,andawindow.Surfacetemperaturesandairvelocityprofilesaresoughtinordertodeterminetheoverallcomfortoftheroomforitsoccupants.Table1.1:Geometrical,Thermal,andFlowBoundaryConditionsfortheDiffuserandWindowSizeTemperatureVelocityInletDiffuser0.2m0.3m13.5C0.85m/sWindow3.65m1.16m30.9C---Table1.2:SizeandCapacityoftheHeatSourcesHeatSourceSizePowerBaseboardHeater1.2m0.1m0.2m1500WPerson0.4m0.35m1.1m75WComputer10.4m0.4m0.4m108WComputer20.4m0.4m0.4m173WLamp0.2m1.2m0.15m34WFigure1.1:GeometryoftheOfficeVentilationProblemStep1:OpenandDefineaNewJob1.StartAirpak,asdescribedinSection1.5oftheUser'sGuide.WhenAirpakstarts,theOpenjobpanelwillopenautomatically.2.Specifyanameforyourjob.(a)IntheSelectthejobtoopentextbox,type/officeattheendofthepath.(b)ClickAccept.Airpakwillcreateadefaultroomwiththedimensions10m3m10m,anddisplaytheroominthegraphicswindow.Youcanrotatetheroomaroundacentralpointusingtheleftmousebutton,oryoucantranslateittoanypointonthescreenusingthemiddlemousebutton.Youcanzoomintoandoutfromtheroomusingtherightmousebutton.Torestoretheroomtoitsdefaultorientation,clickonOrientintheOptionsmenuandselectHomefromtheOrientdrop-downlist.3.Modifytheoverallproblemdefinitiontoincludetheeffectsofchemicalspeciesmixingandturnontheidealgaslaw.FileProblem(a)SelectOnnexttoSpeciesandclickEdit.AirpakwillopentheSpeciesdefinitionspanel.i.SettheInitialconcentrationofh2oto50.ii.SelectRHfromthemenutotherightoftheInitialconcentrationfieldforh2o.RHistherelativehumidityoftheairintheroomspecifiedasapercentage.iii.ClickAccept.(b)UnderGravityvector,clicktheAdvancedbutton.TheAdvancedproblemsetuppanelwillopen.i.TurnontheIdealgaslawoptionandtheOper.densityoptionandkeepthedefaultvaluesfortheoperatingpressureanddensity.ii.ClickAccept.(c)KeepthedefaultsettingsforallotherparametersintheProblemsetuppanel.(d)ClickAccepttosavethenewsettings.Step2:BuildtheModelTobuildthemodel,youwillfirstresizetheroomtoitspropersize.Thenyouwillcreatethefeaturesoftheroom,includingpeople(2),computers(2),lights(6),tables(2),aventilationreturnandinputdiffuser,aradiator,apartition,andwalls.1.Resizethedefaultroom.ModelRoom(a)IntheroomEditpanel,enterthefollowingcoordinates:xS0yS0zS0xE5yE3zE-4(b)ClickModifytoresizetheroom.(c)ClickonOrientintheOptionsmenuandselectIsometricfromtheOrientdrop-downlisttoshowanisometricviewoftheroomscaledtofitthegraphicswindow.Note:Thewallsoftheroomareadiabaticanddonotparticipateinradiation,bydefault.Toincluderadiationeffectsattheboundariesoftheroom,youwilldefinewallobjectsattheboundarieslaterinthisstep.2.Createthefirstpersonintheworkspace.Note:ThereisaPersonobjectinAirpak;however,forthissimulation,therepresentationofthepeoplewillbesimplified,i.e.,thepeoplewillberepresentedbyhollowblocksthatareenergysources.Tutorials2and3willmakeuseofthePersonobject.ModelBlocks(a)ClickNewintheblockEditpanel.Airpakwillcreateanewhollowprismblockinthecenteroftheroom.Youwillneedtochangeboththesizeoftheblockanditslocationwithintheroom.(b)ClickEdittomodifythedefaultblockintheBlockspanel.(c)Enterthefollowingcoordinatesforthefirstperson:xS1.4xE1.8yS0yE1.1zS-0.6zE-0.95(d)IntheBlockspanel,settheTotalpowerunderThermalSpecificationtobe75W.(e)Enterthenameperson1intheNamefield.(f)ClickUpdatetomodifytheblock.3.Createthesecondperson.(a)ClickNewintheBlockspanel.(b)Enterthefollowingcoordinatesforthesecondperson:xS3.6xE4.0yS0yE1.1zS-3.05zE-3.40(c)IntheBlockspanel,settheTotalpowerunderThermalSpecificationtobe75W.(d)Enterthenameperson2intheNamefield.(e)ClickUpdatetoupdatetheblock.4.Createthefirstcomputer.Thecomputerswillberepresentedbyhollowblocksinfrontofthepeopleintheoffice.(a)ClickNewintheBlockspanel.(b)Enterthefollowingcoordinates:xS1.4xE1.8yS0.7yE1.1zS0zE-0.4(c)SettheTotalpowerto108W.(d)Enterthenamecomputer1intheNamefield.(e)ClickUpdatetoupdatetheblock.5.Createthesecondcomputer