基于热电制冷的机载电子设备冷却舱内自然对流特性研究

Research on Characteristics of Natural Convection in Cooling Chamber of Airborne Avionics Based on Thermoelectric Refrigeration

通过实验研究和数值模拟的方法探讨了热电制冷器(Thermoelectric cooler,TEC)的排布方式对机载电子设备冷却舱内空气自然对流特性的影响。结果表明:空气遇冷后,温度降低,密度变大,并以缓慢的速度开始下沉,其运动形式由变形运动逐渐过渡到旋转运动。在舱内顶部布置TECs更有利于流场的发展,但空气下沉到冷却舱底部时易产生振荡解,出现分岔流和二次流,流动进入混沌状态。通过6种设计案例的对比分析,给出了具有最小的温度不均匀系数和最低的平均空气温度的最佳机载电子设备冷却舱内TEC排布方式。

The effect of the arrangement of thermoelectric cooler(TEC)on the natural convection characteristics of air in the cooling chamber of airborne avionics is studied by experimental research and numerical simulation.The results show that when the air is cooled,its temperature decreases while its density increases,and it begins to sink at a slow speed.Its motion form gradually transitions from deformation to rotation.It is more beneficial to the development of flow field to arrange all the TECs at the top of the chamber.However,when the air sinks to the bottom of the cooling chamber,it is easy to produce oscillation solutions,fork flow and secondary flow,and the flow enters the chaotic state.Through comparative analysis of six design cases,the best arrangement of TEC in the cooling chamber of the airborne avionics with the minimum temperature inhomogeneity coefficient and the lowest average air temperature is given.