阵列微射流冲击肋化表面传热特性的研究

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1、北京工业大学硕士学位论文阵列微射流冲击肋化表面传热特性的研究姓名：贾真申请学位级别：硕士专业：热能工程指导教师：夏国栋20080401AbstractRapidprogressofMicro-／nano-technologymakesemiconductordeveloptolligh-power,Miniature，high—densityatpresent，whichleadtohigherheatfluxonchip’Ssurfacetobedissipated．What’Sthekeytoensurestabilizationandprolonglifeofprodu

2、ctionishowtotakeheatawayeffectively,reducehotspotofinterface,uniformtemperaturefield．Designandfabricationoftraditionalcoolerfailtosolvethisproblem，moreefficientcoolingmethodsneedtobesought．Liquidarrayjetimpingementhavehighheattransfercoefficient，duetoverythinthermalandhydraulicboundarylayer

3、sinstagnationzoneformedbyhigh-speedliquidimpingingontargetsurface．Reasonablearrayconfigurationincreasesheattransfercoefficientanddecreasesdifferenceinsurfacetemperaturefurther．Ifheattransfersurfaceistreatedwithpinfins，heattransferareainUnitvolumewillincreasegreatlyaswellasturbulence．Jetimpi

4、ngementcoolingmethodmustbemainstreamtomeetfuturehighheatfluxdissipation．Theheattransferofmicro-jetarrayimpingingoncircularpin-finsurfacehasbeenstudiedfirstly．Effectsofjetdiameter,jet--to_jetspacing,jet··to-·targetspacing,Reynoldnumberetconheattransferarediscussed．Wefindthatsubmergedjetexcel

5、sfree—surfacejetIncreaseofReynoldnumbercanenhanceheattransferaswellasdecreaseofjet-to-jetspacing．Jet—to-targetspacinghavesignificanteffectonheattransferforsubmergedandfree—surfacejet．Enhancementfactorswillincreasewithincreasingliquidflowrateforsubmergedandfree-surfacejetsandtheslopeofchivet

6、endstobemild．TheenhancementfactorofsubmergedjetincreaseswithincreaseofH／d,anditisinsensitivetothevariationofH／dforfree—surfacejet．TheconvectionresistancewilldeclinewiththeincreaseofReynoldnumber,thenwiththecontinuousincreasingofReynoldnumbertheconvectionresistancechangesslowly．Pin—finsurfac

7、ehasgreatpotentialtoreduceconvectionresistance．Thentwotypescoppermicro-jetimpingementcoolingheatsinksconsistingoffivecoppersheetsaredesignedinthispaperandthejetdiameteris0．4mmandO．15mm．Pressuredropandheattransfercharacteristicofsingle-rowandtwo-rowIII北京下