直喷汽油机中空锥形燃油喷雾的雾化和蒸发模型

高压旋流中空燃油喷雾日益广泛地应用于缸内直喷(GDI)汽油机中，为此发展了一种适合于模拟这种燃油喷雾雾化过程的薄膜喷雾模型．燃油薄膜的破碎过程采用表面波破碎理论来模拟．对Spalding蒸发模型和油滴阻力模型进行了改进，用来计算油滴的蒸发和阻力变形过程，同时引入初始喷雾液团的计算模块．在多维内燃机计算程序KIVA3的基础上建立了改进的数值计算模型，并对不同喷射条件下的定容压力容器中空旋流燃油喷雾过程进行了数值计算，对计算和实验所得的喷雾特性包括油束外形结构，油束喷雾贯穿度和油滴粒径进行了详细的比较，同时对单液滴的蒸发过程也进行了数值计算，油束模型的计算结果与实验结果吻合良好。

Modeling Atomization and Evaporation Processes of Hollow-Cone Fuel Sprays for GDI Engine

A sheet spray model is proposed to simulate the atomization processes of pressure-swirl hollow-cone fuel sprays which are widely used in gasoline direct injection (GDI) engines these days. Breakup of the liquid sheets is modeled by using the surface wave breakup theory. Improved Spalding-type evaporation and drop drag models are used to calculate drop evaporation and drop dynamic drag, and an initial spray slug module is introduced into calculation. All models are implemented in a multidimensional computer code KIVA3 and used to study hollow-cone fuel sprays for different injection conditions in a constant pressure chamber. Detailed comparisons of computed and experimental spray characteristics such as spray contour structures, spray tip penetrations, drop sizes(SMD) are made. A single droplet evaporation processes are also simulated. The computational result from these models coincides with the experimental one very well.