二甲醚清洁燃料均质压燃燃烧数值模拟研究
NUMERICAL SIMULATION OF HOMOGENEOUS
CHARGE COMPRESSION IGNITION COMBUSTION
of emission. HCCI combustion can
not only ensure both the
high x and smoke of the remarkable characteristics of HCCI
combustion is that the
are controlled by the chemical kinetics, so the are used to new kinetic mechanism for DME consists of 79 species and 399 reactions. To consider the effect of wall heat transfer, a wall heat transfer model is added into the HCT code. By this method, the effects of the compression ratio, the fuel-air equivalence ratio, the intake charge heating, the engine speed, EGR and fuel additive on the HCCI ignition and combustion are studied. The results show that the HCCI combustion fueled with DME consists of a low temperature reaction heat release period and a high temperature reaction heat release period. It is also founded that increasing the compression ration, the equivalence ratio, the intake charge temperature and the content of H 2O 2, H 2 or CO cause advanced ignition timing. Increasing the engine speed, adoption of cold EGR and the content of CH 4 or CH 3OH will delay the ignition timing.