振荡热管中气液两相运动的数值模拟

Numerical simulations of vapor-liquid phase transition in oscillating heat pipes

为了从流体流态角度对振荡热管初始化和运行过程中的气液两相流动进行研究,采用VOF(volume of fluid)方法追踪气液界面,针对界面表面张力采用CSF(continue surface force)模型并添加动态接触角、气液相变UDF(user defined function)建立数理模型,利用Fluent软件对其进行数值模拟。通过与可视化实验结果进行对比,验证了模型的精确性和可靠性。结果表明:振荡热管初始化和运行过程中,气泡的产生和形态变化是管内工质循环的重要动力;动态接触角模型能够更精准的模拟这一过程。

In order to study the vapor-liquid phase transition in the process of initialization and operation from the perspective of fluid and flow regime,the VOF （volume of fluid） method was adopted to trace the vapor-liquid interface.And considering the interfacial surface tension, the mathematical model was established by using CSF （continue surface force） model and adding dynamic contact angle and the UDF （user defined function）, then nu- merical simulation was carried out through Fluent software.By comparing with the visual experiment results,the ac- curacy and reliability of the model were verified.The results showed that during the initialization and operation of the oscillating heat pipe, the generation and morphological change of bubbles were important driving force for the circu- lation of working fluid, and compared with the static contact angle model,the dynamic contact angle model simulate the initialization and operation of the oscillating heat pipe more accurately.