2024年4月22日发(作者：)

Developmentandapplicationofan

underhoodairflowsimulationmethodology

forpassengercars

JeroenVancoillie

Supervisor(s):SebastianVerhelst,MicheldePaepe,RogerVanWissen

Abstract—SimulationhasrecentlybeenintroducedatToyota

MotorEuropetooptimizethedesignofvehiclecoolingsystems.

Thisabstractdescribesthedevelopedmethodologytosolvethe

airflowthroughtheenginecompartmentandpredicttheperfor-

proceduretobuildasimulationmodelisdiscussedandthese-

ythemodel’sprediction

performanceisillustratedbyanexampleresult.

Keywords—Vehiclecooling,underhood,heatexchanger,CFD

III.M

ETHODOLOGYANDMODELS

Figure1summarizestheproceduretobuildandval-

iousstepsare

treatedinmoredetailbelow.

I.I

NTRODUCTION

V

’s

newvehiclesfeaturehighhorsepowerenginesand

anunderhoodcompartmentcrowdedwithtechnologyto

satisfycostumers’expectationsregardingperformance,

safety,er

theshorteneddevelopmenttimesandhighnumberof

powertrainvariantsareplacingadditionalstressonthe

designersofcoolingsystems.

Theairflowthroughthefrontendheatexchangersis

manufacturersaretakingthisintoconsiderationwhen

anycontradictingfactors

aredefiningthefrontenddesign,aclearunderstanding

oftheairflowbehavioranditsinfluenceonthecooling

veresortedtocompu-

tationalfluiddynamics(CFD)togetthisunderstanding.

TheaimofmythesisworkwastoconfirmCFDas

avaluabletoolforcoolingsystems’rto

serveasavirtualsign-off,thesimulationmustbeableto

predictvaluesforcriticalcoolingperformanceparame-

ters,suchasenginecoolanttemperatures.

II.S

COPEOFTHEWORK

Inthecourseofthisprojectwedevelopedatime-and

cost-efficientsimulationmethodologyandapplieditto

aspecifiicleofinterestwasaToy-

otaAvensis2.2lDieselwitha6-speedautomatictrans-

lingmodulecontainsacondenser,full

faceintercooler,ngloop

fortheautomatictransmissionfluid(ATF)bringsabout

istsofanair-to-oilcooler

andalittletubularwater-to-oilcoolerintheradiatorout-

lettank.

uretobuildandvalidatethemodel

odeling

WeselectedtheCFDsoftwareSTAR-CCM+toper-

formtheanalysis[1].Thisprogramusesthefinite-

volumemethodtonumericallysolvetheNavier-Stokes

equationsforfluidbehavior.

SincetheReynoldsnumberforflowaroundavehicle

isintherange10

6

-10

7

turbulencemustbeaccounted

eweareonlyinterestedintheinfluenceof

turbulenceonthemeanflow,therealizablek-