二甲醚清潔燃料均質(zhì)壓燃燃燒數(shù)值模擬研究畢業(yè)論文模板

1、畢業(yè)論文 畢業(yè)論文論文題目：學生姓名:學生學號:專 業(yè):指導教師:系:二甲醚清潔燃料均質(zhì)壓燃燃燒數(shù)值模擬研究NUMERICAL SIMULATION OF HOMOGENEOUSCHARGE COMPRESSION IGNITION COMBUSTIONFUELED WITH DIMETHYL ETHERABSTRACTHCCI (Homogenous Charge Compression Ignition) combustion ha

2、s advantages in terms ofefficiency and reduced emission. HCCI combustion can not only ensure both the high economicand dynamic quality of the engine, but also efficiently reduce the NOx and smoke emission.Moreover, one o

3、f the remarkable characteristics of HCCI combustion is that the ignition andcombustion process are controlled by the chemical kinetics, so the HCCI ignition time can varysignificantly with the changes of engine configura

4、tion parameters and operating conditions. In thiswork numerical scheme for the ignition and combustion process of DME homogeneous chargecompression ignition is studied. The detailed reaction mechanism of DME proposed by

5、AmericanLawrence Livermore National Laboratory (LLNL) and the HCT chemical kinetics code developedby LLNL are used to investigate the ignition and combustion processes of an HCCI engine fueledwith DME. The new kinetic me

6、chanism for DME consists of 79 species and 399 reactions. Toconsider the effect of wall heat transfer, a wall heat transfer model is added into the HCT code. Bythis method, the effects of the compression ratio, the fuel-

7、air equivalence ratio, the intake chargeheating, the engine speed, EGR and fuel additive on the HCCI ignition and combustion arestudied. The results show that the HCCI combustion fueled with DME consists of a lowtemperat

8、ure reaction heat release period and a high temperature reaction heat release period. It isalso founded that increasing the compression ration, the equivalence ratio, the intake chargetemperature and the content of H2O2,

9、 H2 or CO cause advanced ignition timing. Increasing theengine speed, adoption of cold EGR and the content of CH4 or CH3OH will delay the ignitiontiming.Key words: HCCI, chemical kinetics, numerical simulation, DME, EGR英