来流速度对防冰表面溢流水流动换热的影响

摘要

为研究来流速度对防冰表面溢流水流动形态及换热的影响,基于空气-水两层相互作用的质量、动量和能量守恒,建立防冰表面溢流水水膜流动换热及破裂的数学模型,分析了防冰表面溢流水在不同来流条件下的流动形态和表面换热情况.计算分析表明:来流速度增加时,防冰表面相同位置处的连续水膜厚度减小,水膜破裂位置随之延后;较高来流速度条件下,破裂处水膜厚度稍有增加,使得破裂后形成的溪流厚度和宽度增大;作为主要的表面散热项,连续水膜表面蒸发及对流换热热流均随来流速度的增加而增大.此外,由水膜破裂引起的表面溢流水流态变化对防冰表面蒸发热流有一定影响.%The purpose of this paper is to investigate the effect of free stream velocity on the runback water flow and heat transfer on the anti-icing surface.Based on the mass,momentum and energy conservations of the runback water flow and the air flow,a mathematical model of the runback water film flow and rivulet flow was developed to investigate the effect of the free stream velocity on the heat and mass transfer on the anti-icing surface. The computation analysis indicates that the water film thickness at the same position on the anti-icing surface decreases with the free stream velocity increasing,and the rivulet thickness and width at the breakup point increase due to larger water film thickness at higher free stream velocity.Meanwhile,as the main heat losses on the anti-icing surface,the evaporation heat flux and the convection heat flux on the water film surface increase with the free stream velocity increasing. In addition, the characteristics of the heat and mass transfer on the dry surface,the fully wet surface and the partially wet surface were also investigated.The results show that the patterns of the runback water have some influence on the heat and mass transfer on the anti-icing surface.