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1、二甲醚清洁燃料均质压燃燃烧数值模拟研究化学系学号姓名指导教师姓名摘要均质充量压缩着火（HCCI）燃烧，作为一种能有效实现高效低污染的燃烧方式，能够使发动机同时保持较高的燃油经济性和动力性能，而且能有效降低发动机的NOx和碳烟排放。此外HCCI燃烧的一个显著特点是燃料的着火时刻和燃烧过程主要受化学动力学控制，基于这个特点，发动机结构参数和工况的改变将显著地影响着HCCI发动机的着火和燃烧过程。本文以新型发动机代用燃料二甲醚（DME）为例，对HCCI发动机燃用DME的着火和燃烧过程进行了研究。……。关键词均质充量压缩着火，化学动力学，数值模拟，二甲醚，EGR，燃料添加剂NUMERICALSI
2、MULATIONOFHOMOGENEOUSCHARGECOMPRESSIONIGNITIONCOMBUSTIONFUELEDWITHDIMETHYLETHERAbstract：HCCI(HomogenousChargeCompressionIgnition)combustionhasadvantagesintermsofefficiencyandreducedemission.HCCIcombustioncannotonlyensureboththehigheconomicanddynamicqualityoftheengine,butalsoefficientlyreducetheNO
3、xandsmokeemission.Moreover,oneoftheremarkablecharacteristicsofHCCIcombustionisthattheignitionandcombustionprocessarecontrolledbythechemicalkinetics,sotheHCCIignitiontimecanvarysignificantlywiththechangesofengineconfigurationparametersandoperatingconditions.Inthisworknumericalschemefortheignitiona
4、ndcombustionprocessofDMEhomogeneouschargecompressionignitionisstudied.ThedetailedreactionmechanismofDMEproposedbyAmericanLawrenceLivermoreNationalLaboratory(LLNL)andtheHCTchemicalkineticscodedevelopedbyLLNLareusedtoinvestigatetheignitionandcombustionprocessesofanHCCIenginefueledwithDME.Thenewkine
5、ticmechanismforDMEconsistsof79speciesand399reactions.Toconsidertheeffectofwallheattransfer,awallheattransfermodelisaddedintotheHCTcode.Bythismethod,theeffectsofthecompressionratio,thefuel-airequivalenceratio,theintakechargeheating,theenginespeed,EGRandfueladditiveontheHCCIignitionandcombustionare
6、studied.TheresultsshowthattheHCCIcombustionfueledwithDMEconsistsofalowtemperaturereactionheatreleaseperiodandahightemperaturereactionheatreleaseperiod.Itisalsofoundedthatincreasingthecompressionration,theequivalenceratio,theintakechargetemperatureandthecontentofH2O2,H2orCOcauseadvancedignitiontim
7、ing.Increasingtheenginespeed,adoptionofcoldEGRandthecontentofCH4orCH3OHwilldelaytheignitiontiming.Keywords:HCCI,chemicalkinetics,numericalsimulation,DME,EGR,fueladditive7二级标题序数顶格写，空一格写标题，黑体四号，单倍行距。绪论通常为第一章，三号黑体居中，上下各空一
