燃烧室冷却通道液态甲烷两相充填过程数值模拟

液氧甲烷发动机启动过程中,相比管路充填,液态甲烷充填燃烧室冷却通道存在更加剧烈的非稳态换热和相变过程。通过追踪充填界面,建立一维分相集总参数充填模型,采用满足扩散条件的相变模型和界面换热模型计算低温推进剂两相非稳态传质传热过程。基于燃烧室冷却通道挤压试验系统建立了仿真计算模型,进行了甲烷两相充填过程仿真计算。燃烧室喷注器前腔压力在充填过程中形成类似水击的压力峰,压力峰值为3.5 MPa。仿真结果与甲烷充填燃烧室冷却通道试验结果一致。通过降低冷却通道初始壁面温度和降低甲烷入口初始温度均能有效降低压力峰值。

Numerical simulation of high pressure liquid methane two phase priming process in combustion chamber cooling channel

During the starting process of the LOX/CH4 rocket engine, there is a more intense unsteady heat transfer and phase change process in chamber cooling channel primed with liquid methane compared with primed with pipes. By tracking the priming phase surface, a one-dimensional split-phase lumped parameter priming model was established. The phase transition model to satisfy the diffusion condition and the interface heat transfer model were used to calculate the unsteady state mass and heat transfer process of the cryogenic liquid propellant. Based on the extrusion test system of combustion chamber cooling channel, the simulation calculation model was established, and the simulation calculation of methane two-phase filling process was carried out. During the filling process, the pressure in the front chamber of the combustor injector formed a pressure peak similar to water hammer, which reached 3.5 MPa. The accuracy of the simulation model was verified by comparing the calculated results with the test results of cooling channel of cryogenic propellant primed combustion chamber. The peak pressure could be effectively reduced by lowering the initial wall temperature of the cooling channel and the inlet initial temperature of the methane.