表面张力驱动对流对液滴散热影响的机理研究

The Influence of Surface Tension Driven Convection on Droplet Heat Dissipation

摘要: 为了揭示表面张力驱动对流对液滴散热影响的作用机理，本文采取数值模拟方法对热毛细对流(表面张力驱动对流)下的液滴散热进行研究。建立了以硅油作为工质的二维液滴模型，考虑在常重力和微重力两种情况下，对于液滴内部流动与传热特性的影响。结果表明，温差越大液滴内部流速越快，温度梯度变化越剧烈，其热毛细对流的换热效果越明显；热毛细对流使得液滴背部流速较大区域扩大，并且其内部的低速流动区域减少甚至消失，热毛细效应增强液滴换热效果得到明显提升；重力水平的增大，液滴的整体散热性能也得到增强。

Abstract: In order to reveal the mechanism of the effect of surface tension driven convection on droplet heat dissipation, this paper adopts numerical simulation methods to study droplet heat dissipation under thermocapillary convection (surface tension driven convection). A two-dimensional droplet model using silicone oil as the working fluid was established, considering the effects of constant gravity and microgravity on the internal flow and heat transfer characteristics of the droplet. The results indicate that the larger the temperature difference, the faster the internal flow velocity of the droplet, and the temperature gradient changes. The more intense the heat, the more obvious the heat transfer effect of capillary convection; The thermocapillary convection expands the area with high velocity on the back of the droplet, and reduces or even disappears the low-speed flow area inside. The thermocapillary effect enhances the heat transfer efficiency of the droplet and is significantly improved; The increase in gravity level enhances the overall heat dissipation performance of droplets.