旋转热管流动和传热数值模拟

CFD Modeling on Fluid Flow and Heat Transfer in a Rotating Heat Pipe

本文对旋转热管内部工质的流动和传热机理开展研究,建立数学模型,采用VOF模型描述两相流动和传热传质过程,考虑了相变饱和温度和饱和压力的依变关系,获得了工质的速度、温度以及两相分布特性。研究表明,冷凝端和绝热端交界处热阻较大,壁面过冷度大;旋转热管轴向热阻很小,具有较好的等温性;随着传热量增大,冷凝端过冷度和蒸发端过热度均增大,总热阻增大。结果表明该方法可以较好地模拟旋转热管内工质的流动和传热特性。

A numerical model was built to sinmlate the flow and heat transfer phenomena during the operation of a rotating heat pipe （RHP）. The volume of the fluid （VOF） model was employed for the simulation of two phase flow as well as the heat and mass transfer process in the RHP. The dependence of saturated pressure on the operation temperature is considered. The performance of the RHP such as velocity field, phase distribution and the temperature contours are examined under different operation conditions. The results indicated that the RHP has an isothermal characteristic where a small axial thermal resistance is found. The overall thermal resistance increases with the increase of heat load imposed on the RHP. A relative low wall temperature is observed near the junction of the condensation section and the adiabatic section, indicating a large thermal resistance through the liquid film in this region. It is concluded that CFD is a useful tool to model the model and explain the flow and heat transfer in a rotating heat pipe.