车用柴油机燃烧和热流分析的数值研究

Numerical Simulation of Combustion and Heat Flux for Vehicle Diesel Engine

利用商用软件STAR-CD及ES-ICE对某D6114柴油机在的缸内燃烧过程进行了数值模拟计算,分析和比较了不同喷油提前角对缸内燃烧过程和燃烧室表面热流的影响。研究结果表明:喷油提前角提前,柴油机缸内的燃烧效果优于喷油提前角推迟,燃烧过程中缸内的压力和温度比推迟喷油提前角时要大,同时缸内的最高燃烧压力和最高温度也高;喷油提前角对缸盖和活塞顶壁面平均热流的影响与其对缸内平均温度的影响相似,对缸套壁面的影响是喷油提前角提前越早,传给缸套的热流越小。数值计算结果为高功率、高强化和低热损的柴油机设计提供理论依据。

In this paper, A comerical software of STAR-CD and ES-ICE was used to simulate the influences of fuel injeciton timing on combustion of engine and the surface-averaged heat flux on combustion chamber wall in a in-line six-cylinder diesel engine. The result shows that the in-cylinder pressure and temperature increased with the advance of the fuel injection timing while the total comhusition duration,the high peak pressures and temperature are higher than that of retard of fuel injection timing. The predicted variation of heat flux on cylinder head and piston wall caused by the injection timing liked its effection on predicted cylinder tempeatures. The predicted heat flux of cylinder liner wall for advancement of the injection timing is less than that of retardment of the injection timing. The simulated results also provided theoretical referenee for design of diesel engine with high engine power density,peak torque density and low heat loss.