柴油机准均质混合气形成的数值模拟

利用KIVA-3V模拟了一台单缸二冲程柴油机通过早喷形成准均质混合气的过程，分析了喷嘴的不同结构对缸内混合气浓度场和温度场的影响。模拟计算表明，利用早喷可以形成稀薄准均质混合气；燃烧室形状影响混合气浓度场和温度场。为使稀薄准均质混合气在缸内合理分布，在不改变活塞ω形状的条件下，使用单孔喷嘴能有效避免燃油碰壁的发生。

Numerical Simulation on Quasi-Homogeneous Mixture Formation in Diesel Engines

Using software KIVA-3V, a simulation on the process of quasi-homogeneous mixture formation by means of early injection in a single-cylinder two-stroke diesel engine with to shaped combustion chamber is conducted. The effects of different structures of nozzle on the density and temperature fields of in-cylinder mixture are analyzed. The results show that the lean quasi-homogeneous mixtures can be formed by early-injection, and the shape of combustion chamber has an obvious effect on density and temperature fields of mixture. With to shaped combustion chamber, using single-orifice nozzle can effectively avoid the fuel spray impinging on the wall, resulting in a more rational distribution of lean quasi-homogeneous mixtures in the chamber.