中文摘要：

基于大涡模拟湍流模型和流体体积法对燃油在喷孔内部的流动和近嘴区域的射流雾化过程进行了数值模拟,运用大涡模拟方法求解气液相的湍流流场,运用流体体积法追踪气液两相流体的界面。模拟结果展现了喷雾初始阶段油束尖梢形成的＂蘑菇头＂形态及其破碎机理,验证了K-H不稳定波的增长是导致射流雾化的原因。深入分析还发现射流表面初始扰动源是液体内部湍流扰动和喷孔出口处边界层松弛共同作用的结果。

英文摘要：

Simulation of internal flow and near-field jet atomizing process of nozzles based on large eddy simulation（LES） and volume-of-fuid（VOF） was conducted.LES is employed for solving turbulent field of two-phase flow,and VOF can track the interface of mixed flow.The numerical results reveal that ＂mushroom head＂ is formed and breakup mechanism at the tip of initial spray,the origin of the jet-string breakup is validated to be the K-H instable wave.Further analysis found that initial perturbations of jet-string interface is effected by both internal turbulent of liquid and boundary relaxation of nozzle exit.