单液滴撞击水平冷板面的模拟研究

Numerical Simulation of the Impact of Single Droplet on Cold Horizontal Plate Surface

针对喷雾冷冻干燥中液滴在设备壁面的冷冻沉积问题,在前期单液滴撞击水平放置冷板面的实验基础上,建立了单液滴与冷板面撞击的模型,利用水平集方法与固化模型相结合,模拟了蒸馏水液滴(直径为3.2,mm,温度为293,K)分别从100、250、500,mm高度撞击不锈钢板面(温度为268,K和253,K)的过程.模拟的最大铺展直径同实验对比,误差小于10%,证明该模型可适用于低黏度、低密度的单液滴撞击水平冷板面的情况.

In spray-freeze drying（SFD）,freeze deposition of liquid droplets on the equipment walls has become a new chal-lenge to its applications. Based on the previous experimental results of droplet collision with cold horizontal solid plates,a model of a single droplet collision with cold solid plates was established with the combination of the Level Set method and the solidification model to simulate the impacting process of the distilled water droplet（3.2,mm in diameter,at 293,K）on the stainless steel plate（268,K or 253,K）from the height of 100,mm,250,mm and 500,mm,respectively. The simulation results of maximum spreading diameter were compared with the experimental data and the errors were less than 10%,which indi-cates that the model is suitable for dealing with the impact of droplets of low viscosity and low-density on the cold horizontal plate surface.