建立丁一个基于喷孔两相流场的柴油一次雾化模型,根据喷孔出口气液两相分布的特点,将射流分为空穴区和液体区,两个区表现不同的雾化作用。从能量守恒的角度,描述了两区中由空穴溃灭和湍流扰动合成的总破碎能转化为破碎液滴的表面能和径向动能的一次雾化过程。模型运用于KIVA程序中,并用于轴对称和非轴对称两种喷孔的喷雾模拟,在与Hiroyasu喷雾特性经验公式的比较中得到初步验证,并模拟出非轴对称喷孔喷雾的非轴对称结构。
A primary breakup model for diesel spray based on two-phase flow in injector nozzle is proposed. According to the distribution of vapor and liquid phase at exit of nozzle hole, the jet is divided into cavitation zone and liquid zone, which show different atomizing effect. From the opinion of energy conservation, the model describes the primary breakup process in two zones as follow, the total breakup energy coming from cavitation collapse and turbulence is converted to surface energy and radial kinetic energy of breakup droplet. KIVA code with this breakup model is applied to modeling symmetric and asymmetric nozzles spray. The simulated results are proved by Hiroyasu empirical fornmlation, arid show asymmetric structure in asymmetric nozzle spray case.