基于SIMPLEC算法的高温热管启动特性数值模拟

Numerical Simulation of High-temperature Heat Pipe Startup Characteristic Based on SIMPLEC Algorithm

为研究高温液态金属热管的瞬态特性,开发了高温热管瞬态分析程序,程序可模拟高温液态金属热管自凝固状态启动过程中涉及到的复杂的相变、蒸气流动及气液交界面的传质传热特性。热管管壁与吸液芯区域采用纯导热模型,考虑了吸液芯内部工质的熔化和凝固以及气液界面的蒸发和冷凝。蒸气模型采用一维的尘气模型(DGM),该模型可精确描述热管启动过程中不同阶段的蒸气的运动特性。热管启动过程中蒸气为高度可压缩,因此蒸气速度与压力的求解采用可压缩流动的SIMPLEC算法进行计算。最后程序模拟了钠热管的启动过程,并与试验数据进行了比较。结果表明,程序模拟结果与试验数据符合较好。

The liquid-metal heat pipe transient analysis code has been developed for the purpose of researching the startup characteristic of liquid-metal heat pipes from a frozen state. The code is capable of simulating the complex process of phase-change, the vapor flow and the transfer of mass and heat on liquid-vapor interface during startup. The pure-conduction model was used in pipe wall and porous wick region with the considera- tion of fusion/solidification and evaporation/condensation process. The dusty gas model was used to describe the various vapor flow regimes. Velocity and pressure of vapor were solved by the compressible SIMPLEC algorithm since the vapor was highly com- pressible during startup. The startup of a sodium heat pipe was simulated by using the code and the results were compared with experiment data. The results show that numer- ical results agree well with experiment data.