变加速度对低熔点金属相变传热特性的影响

Investigation on influence of variant acceleration on phase change heat transfer characteristics of low melting point metal

针对海洋摇摆环境和变速飞行条件等复杂变加速度环境下低熔点金属相变材料相变传热基本特性不明晰,限制其在舰载、弹载、机载电子设备热控领域的应用等问题,构建了变加速度条件下固液相变问题输运模型,利用双分布函数多松弛因子格子波尔兹曼方法编写了相应的计算代码,对典型海洋摇摆环境和导弹飞行条件下相变热沉热控特性进行了分析.结果表明:在本研究分析的工况下,海洋摇摆条件会引起相变热沉传热强度±21%的波动,从而影响热沉的瞬时热控性能;导弹俯冲过程中巨大的加速度会增强相变材料液相区域的自然对流,使相变传热强度增加67%,但也会增加热沉热界面温度的不均匀性,增大局部过热风险.

The phase change heat transfer characteristics of low melting point metal under complicated environment,such as ocean rolling condition and flight acceleration-varying condition,is unclear,which hinders its application in the field of thermal control of electronics in ship,missile and aircraft. The transportation model of solid-liquid heat transfer problem under complicated environment was provided and typical cases were numerically studied. The rolling condition leads to ±21% fluctuation of the heat transfer intensity,which will affect the transient thermal control performance of low melting point metal heat sink. The high acceleration under flight condition in missile enhances the natural convection inside the molten region and thus enhance the heat transfer,which is beneficial for the thermal control performance,while the uniform temperature distribution thus resulted needs attention in practice to avoid local overheating.