常压低温环境下抛物面薄壁结构热平衡特性分析

Thermal Balance Characteristics of Parabolic Thin-wall Structures in Cryogenic Environment

空间环境模拟试验是检验航天器可靠性的重要手段,低温环境下航天器的温度分布以及热变形特性是进行试验参数设计的重要依据。以典型的抛物面薄壁结构为对象,分析其在常压低温空间环境模拟试验系统中的热平衡特性,建立其在不同热流密度、导热系数以及辐射系数下的传热模型。通过数值模拟定量获得抛物面结构的体平均温度、面平均温度和温度标准差等关键温度特性参数,分析不同传热形式对传热量和温度均匀性的影响。结果表明,当施加于表面的热流密度从0 W·m^(-2)增加到1500 W·m^(-2)时,抛物面结构的体平均温度升高30 K,表面温度标准差增加至1.5 K,抛物面所受气流总压力减小2.4 N,温度呈中心对称分布;当等效导热系数从20 W·m^(-1)·K^(-1)增加到200 W·m^(-1)·K^(-1)时,抛物面结构的体积平均温度升高2.8 K;辐射系数对表面温度标准差的影响较小,但会影响表面对流传热的热量传递方向。

Space environment test is an important way to validate the reliability of spacecraft,and its temperature distribution and variation characteristics are essential for system design.The present study took a typical parabolic antenna structure as the object,analyzed its thermal balance characteristics in the thermal cycling test system,and established the heat transfer model under different radiation coefficients,external heat fluxes,and equivalent thermal conductivities.The temperature characteristics of the antenna,such as body averaged temperature,surface averaged temperature and temperature standard deviation were quantitatively analyzed by numerical simulation,and the influence of different heat transfer forms on the temperature characteristics is investigated.The results show that when the external heat flow varies from 0 to 1500 W·m^(-2),the temperature of the parabolic antenna tends to be symmetrically distributed,the body average temperature increases by 30 K,the standard deviation of the temperature of surfaces changes by 1.5 K,and the total pressure caused by air decreases by 2.4 N.When the equivalent thermal conductivity varies from 20 to 200 W·m^(-1)·K^(-1),the body average temperature of the parabolic antenna increases by 2.8 K.The effect of the radiation coefficient on the standard deviation of temperature is insignificant,but it determines the direction of convective heat flux on the wall.