中文摘要：

建立了考虑气液界面存在及其表面张力影响的较全面描述振荡热管内气液两相流动、传热传质和相变过程的气液两相流数理模型.模型中气液分布及界面运动采用VOF方法,表面张力影响采用CSF模型,对一典型闭式循环振荡热管起始工作阶段进行数值模拟.结果表明：所建立的模型成功模拟了振荡热管初始气液分布,启动阶段管内的泡状流、柱塞流、环状/半环状流和壁面回流等复杂气液流动流型和转变,以及起始循环阶段环状流和柱塞流在竖直管段内交替出现的现象.结果与相关定性实验观测非常一致,进而分析了启动阶段2个过渡管段内工质的流动及传热.分析表明在绝热段和冷凝段之间的过渡段,工质温度、压力和流型的变化明显,管内传热工况的转变主要发生在该区域内.

英文摘要：

A comprehensive mathematical model including the effects of vapor-liquid interface and surface tension is proposed to describe the vapor-liquid two-phase flow, heat and mass transfer, and the phase change process in oscillating heat pipe （OHP）. The VOF （ volume of fluid） method is used for the vapor-liquid distribution and interface motion and the CSF （ continuum surface force） model is used for the effect of surface tension. The initial operation of a typical closed loop OHP was simulated based on the proposed model. The results indicate that the initial distribution of working fluid, the complex flow pattern such as bubbly flow, slug flow, semi-annular/annular flow, backflow and the flow pattern transition can be predicted by the model. The phenomenon of annular flow and slug flow in alternating vertical tubes at initial circulation stage was also simulated successfully. The results coincide well with the experimental observations. The flow and heat transfer of working fluid in two transition sections at initial operation stage were analyzed. It is shown that the changes of temperature, pressure and flow pattern are obvious in the transition section between adiabatic section and condensing section, where the transition of heat transfer conditions takes place.