过冷大水滴变形与破碎的影响因素

Influence factors on deformation and breakup of supercooled large droplets

过冷大水滴(SLD)结冰过程中,影响水滴变形与破碎及其导致的效应的因素众多,多种影响因素耦合作用于水滴变形与破碎的规律还未得到清晰认识。采用数值计算的手段,模拟了SLD运动过程中的变形与破碎现象,分别研究了水滴直径、流场速度及绕流物体尺寸变化对水滴破碎与变形及其效应的影响。通过研究,提出了包含SLD的典型流场区域划分方法,得到了不同因素对水滴破碎区域面积、物面的水滴收集特性、破碎子水滴分布特性的影响规律,发现水滴直径、流场速度、翼型前缘半径与变形和破碎影响撞击特性的程度呈正相关关系。在此基础上,提出了一个综合影响参数X,线性回归分析的结果初步说明,X是表征水滴变形与破碎及其效应的合适参数。相关工作可以为SLD结冰的计算、试验以及防/除冰设计提供参考。

In the icing of Supercooled Large Droplet (SLD),many factors affect droplets deformation and breakup.The laws of multiple factors influencing on the deformation and breakup of droplets have not been understood clearly.Adopting numerical calculation,the effects of droplets diameter,flow field velocity and the variation of object size on SLD deformation and breakup are studied.Then a method of dividing typical flow fields region including SLD is proposed.The influence laws of different factors on the area of droplets breakup region,the efficiency of droplets collection and the distribution of subdroplets are obtained.It's found that the SLD diameter,air velocity and leading edge radius of airfoil are positively associated with the effect of deformation and breakup to droplets impingement and collection coefficient.On this basis,a comprehensive influence parameter,X,is proposed.The results of the linear regression analysis show that X is an appropriate parameter to characterize the effects of deformation and breakup.The above work can provide reference to the calculation and test of SLD icing and the anti/de-icing design.