湍流扰动对液滴破碎的影响及模拟方法研究  

A simulation method and the effect of turbulence perturbation on droplet breakup

作　　者：齐文亮 明平剑[1] 张文平[1] 彭晔 QI Wenliang;MING Pingjian;ZHANG Wenping;PENG Ye(College of Power and Energy Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2018年第4期709-715,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51479038);中央高校基本科研业务费专项资金项目(HEUCFP201711)

摘　　要：为考虑射流内部湍流扰动对雾化的影响,本文将喷嘴内部湍流扰动量用湍流长度和时间尺度来表示,并以权重的形式加入初次破碎模型中。对比分析了单液滴表面不稳定波和湍流扰动对液滴破碎的影响。计算结果表明:湍流扰动随液滴运动时间的增加对破碎的影响逐渐减小,不稳定波的影响比重逐渐增大;喷嘴内流速越大,湍流扰动量越强,影响的时间越久。对本文提出的破碎模型进行了验证,计算结果表明:湍流扰动会导致液滴的索特尔平均直径(SMD)减小4%左右;随入射压力升高,湍流扰动对贯穿距的影响逐渐增大;虽然二次破碎发生在距离喷嘴较远处,但初始湍流值的大小,还是能影响到二次破碎后液滴大小和速度。In this paper,the effect of turbulence perturbation inside a jet during atomization was investigated.The turbulence inside the nozzle was characterized by the turbulence characteristics of length and time scale,and this was then added into a primary breakup model in the form of a weighted coefficient.First,the effects of an unstable wave and turbulence perturbation on single droplet breakup were analyzed.The results show that the effect of turbulence on droplet breakup gradually reduced with increasing time,while the influence of the unstable wave increased step by step.In addition,a larger jet rate resulted in larger turbulence perturbation energy and a longer influencing time.The model was then validated using experimental data.The predictions showed that the turbulence term can decrease the Sauter mean diameter(SMD)by about 4%,and with increasing injection pressure the effect of turbulence perturbation on breakup length increases.Although secondary breakup occurred far from the nozzle,the initial value of the turbulence term still determined the size and velocity of the secondary droplet.

关 键 词：液滴破碎模型 初次破碎 二次破碎 喷雾贯穿距 湍流扰动 射流内部 喷嘴 雾化 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]