水滴形热管阵列预冷器综合换热特性数值研究

Numerical study on comprehensive heat transfer characteristics of waterdrop-shaped heat-pipe array precooler

提出了一种应用于高超声速飞行器进气预冷的水滴形热管阵列预冷器构想,以实现进气预冷的高效换热和低流动损失。基于将热管处理为恒定温度导热体的简化模型假设,采用数值模拟方法研究了水滴形热管预冷器的流动换热特性以及水滴热管形状、纵向间距和来流马赫数的影响,并与具有相同截面积的圆形热管预冷器进行了对比分析。结果表明,水滴外形减少了外掠高温来流在热管尾缘脱落涡的产生,流动变得平滑。与圆形热管预冷器相比,水滴形热管预冷器极大地减小了高温来流流动损失,仅为圆形热管阵列的30%。虽然温降有所降低,但综合性能因子大于圆形热管预冷器。在本文的研究参数范围内,存在相对较优的水滴形状和热管纵向间距,可以获得更高的综合换热特性;随着来流马赫数增大,预冷器的综合换热特性有所提升。

A novel concept of waterdrop-shaped heat-pipe array precooler was proposed for achieving high-efficient heat transfer and low-loss flow of the inlet air precooling,as applied to the hypersonic vehicle.Based on the simplified model assumption by treating the heat pipe as constant-temperature thermal conductor,numerical simulations were performed to study the flow and convection heat transfer characteristics of waterdrop-shaped heat-pipe array precooler,as well as the influencing roles of waterdrop shape,longitudinal pitch of array and inlet flow Mach number.In addition,a comparison was also made between the waterdrop heat pipe and round heat pipe,both having the same cross-sectional area.The results show that the waterdrop-shaped heat-pipe ar-ray could suppress the shedding vortex of the high-temperature flow at the trailing edge of heat pipe and make the flow smoothly.Compared to the round heat-pipe precooler,the waterdrop-shaped heat-pipe precooler greatly re-duces the flow loss of high temperature inflow inside the channel,which is only 30%of the round heat-pipe ar-ray.Although the temperature drop of the inflow is a little less than the round heat-pipe precooler,the waterdrop-shaped heat-pipe precooler could obtain better comprehensive heat transfer performance.Among the present re-search parameter range,relatively optimal waterdrop shape and longitudinal pitch of array are identified,at which higher comprehensive heat transfer performance is realized.With the increase of inflow Mach number,the comprehensive performance of waterdrop-shaped heat-pipe precooler is improved gradually.