两股湍流射流撞击雾化过程的数值研究 *

Primary Atomization Simulations of Two Turbulent Impinging Jets

关键词:  撞击  雾化  大涡模拟  撞击角  动量比

Key words:  Impinging  Atomization  Large eddy simulation  Impingement angle  Momentum ratio

摘要:

采用新提出的雾化过程仿真算法，对两股湍流射流撞击雾化过程进行了数值研究，重点关注了撞击角和动量比的影响。为精细地模拟湍流对雾化的影响，采用了大涡模拟。对雾场瞬态和统计结果的分析表明，喷雾角随着两股射流撞击角的减小而减小，但液膜的破碎长度反而增加；动量比主要影响雾场的偏斜程度，动量比由1.0增大到2.25时，喷雾偏斜角由[0°]增大到约[23°]。仿真结果与试验结果吻合较好，表明新算法能够较好地反映两股湍流射流的雾化过程。

Abstract:

Primary atomization simulations of the impinging injectors are carried out by a newly proposed method. The impinging injectors with various structures and operating parameters are investigated，emphasizing on the impact of the impingement angles and the momentum ratios between the two turbulent jets. A large eddy simulation model is involved to describe the details of the turbulent flow. The results of the instantaneous and time-averaged properties show that the spray angle decreases and the breakup length of the liquid sheet increases with the decrease of impingement angles. The results also show that the momentum ratio of the two jets mainly affects the direction of resulting spray. When the momentum ratio increases from 1.0 to 2.25，the incline angle of the spray increases from [0°] to [23°]. The good agreement with experimental results indicates that the new method can be used to simulate the impinging process of two turbulent jets properly.