资源描述:
《外文翻译-内燃机冷却风扇设计的新方法.doc》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、大连水产学院本科毕业论文(设计)外文翻译NewDesignMethodForEngineCoolingFanHuangHongbinzhengShiqinLiuShuyanYanWeige(SchoolofVehicularEngineering,BeijingInstituteifTechnology,Beijing100081)AbstractAimToputforwardatypeofmathmodelforoptimizingfan’stwistinglaw.MethodsThismathmodelw
2、asbasedonturbo-machineryeulerequationsandcalculusofvariation,itwasconductedforoptimizingtheaerodynamicparametersalongthebladeheightofthefanandthemathmethodwasproducedfortheoptimizationoffan’stwistinglaw.Resultsthetype6102Qenginecoolingfanwasoptimizedbyuseof
3、thismodel,andthecalculationdatawerecontrastedwiththoseofiso-reactioncoefficiencyflowtypeandfreevortexflowtype.Someproblemsexistinginlongbladecanbesolvedbyuseofabovemethod.ConclusionThedesignparamtersneedn’tbedeterminedartificially,socalculatingresultsaremor
4、erationaltoahighdegreethanthatfromothermethods.Keywords:coolingfan,twistinglaw,optimumdesignThedesignoffanhasbeenahardworkontheorientationofaerodynamicsbecauseoftheomplicatedflowthroughtheblades,sothefanhadbeendesignedbyuseofkaufmantheory.Thislawbelievestha
5、ttheflowthroughthefanbladesisofone-dimension,theairflowparametersatthemeanbladediameteraretakenintoaccount,buttheflowthroughtherootandtipisnegative.Afterthat,fanwasprojectedaccordingtothesimplyradialbalanceequation.Numericalprecisionwasenhancedbyuseofcomple
6、telyradialequilibriumequationandiso-reactionfactoroftwistinglawtodeterminetheair-flowparametersalongthebladeradialdirection,sotheflowlossesoftipandrootarelessentocertainextent.Inthispaper,theauthorsputforwardamathmodelforoptimizingairflowparameteralongblade
7、heightbyuseofeulerequationsandcalculusofvariation.1.MATHMODELWhiletheminutematter△Gflowsaroundthebladewhichisformedbytwoneighboringflowsurfaces,accordingtoEulerequation,fan’spoweris△P=(v2ur2-v1ur1)△G(1)Whereωistheangularvelocityofthefan,v1uisthecircumferent
8、ialspeedatthefaninlet,v2uisthecircumferentialspeedatfanoutlet,r1isthefaninletradius,r2isthefanoutletradius,Forthecaseofnon-guideblade,Eq.(1)becomes△P=v2ur2△G(2)Wesetuptherelationsbetweenr1andr2byuseoft