1、天津大學(xué)碩士學(xué)位論文基于離散小波變換的HCCI爆震特性參數(shù)研究姓名：楊冬冬申請(qǐng)學(xué)位級(jí)別：碩士專(zhuān)業(yè)：動(dòng)力機(jī)械及工程指導(dǎo)教師：堯命發(fā)20070101ABSTRACTHomogeneousChargeCompressionIgnitionOaccl)，whichcombinestheadvantagesofcompressionignition(CI)enginewiththatofsparkignition(SI)engine，couldp

2、rovidehighlyeffectiveandverycleancombustionItisconsideredasanewgenerationcombustion，whichmeetsthestringentfutureemissionlawregulationsandhasgottenallattentionfromacademicandindustryareaAutoignitionprocessofHCCIarecontrol

3、ledbychemicalkinetics，indirectmeanswasintroducedtocontrolHCCIcombustion，forexampleairfuelratiocontrol，intaketemperaturecontrolandmixturecomponentcontr01Inhighloadcondition，combustionrateincreasesexceedinglyduetoverythick

4、mixtureandknockoccursaccompanywithgreatincreasementofcombustiontemperatureandhighNOxemissionsKnockispotentiallydamagingtotheengineandimposesanupperlimitonthepoweroutputofHomogeneousChargeCompressionIgnition(HCCI)Toidenti

5、fyknockratetakesanimportantpartintheresearchofHCCIcombustioncontr01InthispaperHCCIknocksignalwasextratedfromin—cylinderpressurewithDiscretewavelettransfor(DWT)methodandstudiedHCCIknockcharacteristicsparameterwasdefinedto

6、measureknockrates，suchasKnockIntensity噼I)，knockintensitythreshold(KIe)andKnockRate(KR)neeffectsoffuelproperties，intaketemperatureintakepressureandEGRratesonHCCIknockcharacteristicswasstudiedItwasshownthatknockintensity(Ⅺ

7、)withhighoctanenumberfuelsshowedasharplyrisewhenknockoccurred，knockintensitycangiveajudgmentforalightknockmoreeffectivelythanthemaximumriserateofin—cylinderpressuremethodBurknockintensity(KI)withlowoctanenumberfuelsdidno

8、thaveasharplyrisewhenknockoccurredKnockintensitythreshold(KIe)ofhighoctanenumberprimaryReferencefuels(PRF)wasestmates02MPawhilethatoflOWoctanenumberprimaryReferencefuelswas005MPaThestudydemonstratedthattheintaketemperatu

9、reandintakepressuretooklesseffectonthevalueofknockintensitythreshold(KIe)，butfuelspropertiesandenginespecification(compressionratio)hadanobviousinfluenceonthevalueofknockintensitythreshold(KIe)ItwasfoundthatKnockRate(KR)