材料期刊网

目的：设计一种以降低表面热辐射为主的疏导式热控结构，通过对疏导式热控结构的热性能进行仿真计算与试验，探讨其温度场分布影响因素。方法采用FLUENT软件，仿真分析了该热控结构在热源200℃时，隔热材料和通风条件对流场及温度场的影响。采用5 mm厚、导热系数为0.036 W/(m·K)的隔热材料和1 mm厚的纯铝板，制备了总厚度为100 mm的疏导式热控结构，测试在热源200、300、400℃时，距隔热层表面0、5、15、35、55、75、95 mm平面内和热控结构外表面的温度，并与仿真计算结果进行了对比。结果在不通风条件下，热源为200、300、400℃时，热控结构外表面的温度分别为48.1、66.8、87.9℃；在5 m/s通风条件下，热源为200、300、400℃时，热控结构外表面的温度分别为36.5、39.8、47.4℃。结论仿真计算获得的温度值与实测值一致，疏导空间内部受热量辐射的影响随高度的增大逐渐减小，适当采用气体对流机制能够显著降低疏导空间和热控结构外表面的温度。

ABSTRACT:Objective To design a leading thermal control structure dedicated primarily to decreasing surface thermal radi-ation.Methods The effect of thermal insulation materials and ventilation on its flow field and temperature field was investigated by using FLUENT software when the temperature of heat source was 200℃. The 100 mm thick leading thermal control struc-ture was prepared by combining 5 mm thick thermal insulation materials with the thermal conductivity of 0.036 W/(m·K) and 1mm thick pure aluminium plates. The temperature of thermal control structure on its outside surface and different altitude planes with distances of 0 mm, 5 mm, 15 mm, 35 mm, 55 mm,75 mm and 95 mm from that was measured when the temperature of heat source was 200℃, 300℃ and 400℃ respectively. Then the test results were compared with those of simulation. ResultsUnder the condition of without ventilation, the temperature on the outside surface of thermal control structure was 48.1℃, 66.8℃ and 87.9℃ when the temperature of heat source was 200℃, 300℃ and 400℃ respectively. With a wind speed of 5 m/s, the temperature on the outside surface of thermal control structure was 36.5℃, 39.8℃and 47.4℃ when the temperature of heat source was 200℃, 300℃ and 400℃ respectively.Conclusion It is indicated that the results of simulation are basically consistent with the measured values. The influence of thermal radiation on the leading space inside the thermal control structure can decrease when height increases. With proper ventilation, the temperature on the outside surface of thermal control structure and in the leading space can be significantly reduced.