周期性變截面微通道熱沉內流體流動與傳熱特性研究.pdf

1、北京工業(yè)大學碩士學位論文周期性變截面微通道熱沉內流體流動與傳熱特性研究姓名：徐志波申請學位級別：碩士專業(yè)：熱能工程指導教師：夏國棟20090401abstractAbstractAstherapiddevelopmentofindustrialtechnology，miniaturization，reductioninproductsweight，highpowerhavebecomethelatesttrendinelectronic

2、productsdevelopmentAsaresult，theheatfluxinadvancedequipmenthassignificantincreasestraditionaldesignmethodsandmanufacturingtechnologyfailtomeettoday’SdemandsManynewtechniquesforimprovingcoolingtechnologyhavebeenproposed，P

3、eriodicalChangeableCrosssectionMicrochannelheatsinkisoneofthemostoutstandingMicroheatexchanger硼1eCrosssectionofPeriodicalChangeableCross—sectionMicrochannelisPeriodicaChangeable，ontheonehand，thePeriodicaChangeofCrosssect

4、ionleadtothePeriodicaChangeofF1uidboundarylayerwhichenhanceheattransferontheotherhand，thedestrunionofboundarylayercanovercometheviscousforce，reducethefluidresistanceAsaresultoftheresearchforPeriodicalChangeableCross—sect

5、ionMicro—channelheatisstillinitsinfancyTherefore，砸spaperreportsanexperimentalinvestigationonflowandheattransfercharacteristicsassociated、Ⅳitlltheforcedflowofdeionizedwaterinaperiodicalchangeablecrosssectionmicroeharmelhe

6、atsinkResearchresultsforFluidflowcharacteristicshasshownthat：嬲theincreaseoffluidflowthepressuredropofHeatsinkincreaseslargerandlargerInthesameReynoldsnumberthefrictionalresistanceeoefficientofPeriodicalChangeableCrosssec

7、tionMicrochannelisslightlylargerthantheTraditionalMicrochannel，WiththeincreaseinReynoldsnumbertheDifferenceoffrictionalresistancecoefficientismorelargerMicroscaleeffecthnadefluidviscosityincreasedWhenReynoldsnumberiSsmal

8、l(Re5400)，frictionalresistancecoe伍cientincreasessignificantly、^，itlltheReynoldsnumberdecreasedWhenReynoldsnumberislarge(Re400)，astheReynoldsnumberincreased，F(xiàn)rictionalresistancecoefficientdeclineslowlyResearchresultsforFl

9、uidHeatTransfercharacteristicshasshownthat：“astheincreaseofRenumberNubecomemoreandmorelargerSotheMovementoffluidflowiSamajorfactorforconvectiveheattransferHowevertheheatfluxhaslialetodo、析thⅣhinthesameRenumbertheNunumbero

10、fPeriodicalChangeableCrosssectionMicrochannelheatsinkislargerthanthetraditionalMicrochannelheatsinkWiththeincreaseinReynoldsnumber，theDifferenceofNunumbertismoreandmorelargerinthesameflowbutdifferemheatflux，neaveragetemp