环境对大功率柴油机缸内喷雾、燃烧与传热的影响

摘要

The influence of different altitude environments on in-cylinder spray , combustion and heat transfer for high power diesel engine were studied by the quasi-dimensional multi-zone numerical simulation and bench environmental simulation test. The research results show that the maximum delay of fuel nucleus breakup in plateau is 9. 1°, which is larger than that in plain. The breakup distance increases by 29% at least, the penetration extends markedly, and SMD gets longer obviously after first atomization. At 4 500 m altitude, the peak value of heat release rate decreases by 18. 4% , the gravity center position of heat release rate delays near to 4°, the maximum combustion pressure decreases by 18, 8% and its corresponding position delays 0. 6°. The in-cylinder heat transfer of convection and radiation intensifies obviously than that in plain. The research results provide the theoretical reference for studying the performance deterioration and fault mechanism of diesel engine in plateau.%采用准维多区数值仿真和环境模拟试验的方法,研究了不同海拔环境对某大功率柴油机缸内喷雾、燃烧和传热的影响.结果表明:在高原环境下,油核破裂滞后期比平原最大延长9.1°曲轴转角,油滴分裂长度增加29％以上,贯穿度明显增加,一次雾化后,SMD直径显著增加；海拔4500 m,瞬时放热率峰值降低18.4％,放热率重心后移近4°,最高燃烧压力降低18.8％,位置滞后0.6°；缸内对流换热和辐射换热都比平原明显增强.研究结果为探明特殊环境下柴油机性能劣化与故障机理提供了理论参考.