毛细管内脉动两相流动的演化规律和机理研究

Although Front Tracking Method(FTM) , as a kind of direct numerical simulation, has a large amount of storage and calculation，it has prominent advantages in accurately capturing the phase interface, excellently in controlling topology changes, basically using explicit difference and so on. This project is planning to conduct an in-depth mechanism analysis on the oscillating heat pipe (OHP) as a heat transfer component based on phase change, which has shown great potential application in the field of electronic device cooling. The current project focuses on the capillary tube which is a key component of the OHP.The self-consistent models (program packages) will be established by using FTM to simulate the two phase flow inside the capillary with the direct numerical simulation, and the models will be inspected and corrected. The bubble and liquid slug movement within the capillary and morphological changes, the bubble’s coalescence and fusion in tube and the tube boiling phase change process will be further simulated in 2-D and 3-D. And then, through the analysis of the parallel computing and the rule of the fluctuating multiphase flowing in capillary, the complex flow and heat transfer of capillary scales in FTM simulation will be explored. By using a visualizing measurement, it is purposed to investigate the multiphase pulsating flow and heat transfer process in a capillary tube. The influence of the experimental parameters on the influence of the flow pattern transition and evolution regularity in the tube will also be analyzed. Combing with the experiment results, the rule of capillary multiphase flow pulsation will be expounded. The project is trying to make outstanding contributions to expanding the application range of OHP.

Front Tracking Method(FTM）作为直接数值模拟方法的一种，虽然其存储、计算量大,但是具有能精确捕捉相界面、极好的拓扑变化控制以及显式差分的计算格式等突出优势。本项目拟对振荡热管（OHP）这种在电子器件散热领域潜力巨大的相变传热元件进行深入的相变传热机理分析，以OHP工作部件-毛细管为研究对象，应用FTM对毛细管内脉动两相流直接数值模拟，建立FTM自洽模型（程序包）并检验和修正现有模型，对毛细管内气泡和液塞的运动、形态变化、气泡在管内聚并、融合以及管内沸腾相变过程进行2-D和3-D模拟，通过并行计算分析揭示毛细管内脉动多相流动规律，探索多相流复杂流动和传热的FTM模拟方法；通过可视化实验研究毛细管内多相脉动流动和传热过程，分析实验操作参数对管内流型转变和演化规律的影响,结合实验验证数值模拟研究结果，阐明毛细管多相脉动流动规律，为开发高效OHP散热装置提供理论依据。

本项目对振荡热管（Oscillating Heat Pipe）这种在电子器件散热领域潜力巨大的相变传热元件进行了深入的相变传热机理分析，以OHP工作部件-毛细管为研究对象，应用Front Tracking Method对毛细管内脉动两相流直接数值模拟，研究了毛细管内气泡和液塞的运动、形态变化、气泡在管内聚并、融合规律以及气-液相界面演化特性，并对毛细管内脉动流动传热过程中气液界面对脉动热管温度波影响、脉动热管中振荡力对气泡流影响以及阻塞通道中气泡热毛细管迁移的数值模拟，通过计算分析揭示毛细管内脉动多相流动规律，探索多相复杂流动和传热过程的界面追踪模拟方法；通过可视化实验以带气液分离腔树状微通道脉动热管、不同倾斜角度新型板式微流道热管为研究对象，研究了倾斜角度、充液率、热负荷等对毛细管内脉动流的影响规律和不同的流型演变转换规律，研究了热管启动特性规律、热负荷等毛细管内多相脉动流动过程对传热的影响，结合实验验证数值模拟研究结果，阐明毛细管多相脉动流动规律，为开发高效OHP散热装置提供理论依据。