可變進氣管對汽油機流動特性及性能影響的數(shù)值仿真研究.pdf

1、天津大學研究生院2006年6月ABSTRACTABSTRACTAsoneofthekeytechnologiesofelectronicejectionengine，variableintakemanifoldsenabletheenginehavethebetterperformanceatawiderspeedrange，enhancetheflowcoe伍cientunderthedifferentspeedAnditalSOen

2、surethattheenginehasmorefreshchargeunderthehigh—speedandthecylindergashasastrongerswirlandtumbleflowmotionunderthelowspeed，SOthattoimprovetheenginepowerandefficiency，andreducetheexhaustemissionByusingnumericalsimulationm

3、ethod，thispapermainlyresearchestheinfluenceofvariableintakemanifoldsonintakeflowcharacteristicsandperformanceforgasolineengineFirstly，thewaveresonanceandtheenergylossofintakemanifoldwereresearchedindetailThentheprinciple

4、oflength—variableintakemanifoldsinincreasingthefkShchargeincylinderbyresonantintakechargingandthefunctionofsection—variableintakemanifoldsinenhancingtheswirlandtumblemotionspeedingupthecombustionrateandimprovingtheengine

5、performancewereanalyzedOnthebase，thispaperpointedoutthatthevariationcontrolstrategyofintakemanifoldsshouldberationallyoptimized，andboththerequirementsofengineforairflowmotionunderlowspeedandflowcoefficientunderhighspeeds

6、houldbetakenintoaccountAfterstudyingthenumericalsimulationofunsteadyflowinintakemanifolds，acertaingasolineenginemodelwassetupbyusingsimulationsoftwareAVL—BOOSTThroughonedimensionalenginecycleandgasexchangesimulationthein

7、fluenceofthemanifoldlengthonengineperformanceWasfoundoutThenasetofschemeforlengthdeterminationofvariableintakemanifoldsWassummarizedThetheoryofCFDassistedinengineanalysiswasstudiedMoreover，themeshstructurewasresearchedwh

8、ichWasthekeypointtocomputeprecisionThethreedimensionalnumericalsimulationofairflowsintheplenum—variableintakemanifoldsintakeportscylindersystemofgasolineenginewasperformedusingCFDsoftwareFIREThesimulatedflowfieldprovided

9、adetailedinsightintotheinfluenceofrotarybladest)rlesectionvariableintakemanifoldsonflowcharacteristics，swirlandtumblemotionTheresultofsimulationindicatedthatthisdevicecouldchangetheswirlortunableratioinsomedegreeandgives