热力学排气系统低温流体轴向掺混过程研究

Research on Cryogenic Axial-jet Mixing in Thermodynamic Vent System

低温推进剂长时间在轨蒸发量控制问题是发展低温末级、轨道转移运载器以实现未来长时间在轨空间任务的关键;热力学排气系统为蒸发量控制提供了有效方案,而轴向流体掺混过程是热力学排气实现贮箱压力控制的关键。为研究轴向掺混过程下的流体行为特性,对流动、传热、相变过程建立了CFD仿真模型,利用国外地面试验进行了验证,对不同流量、流速、温度、喷口直径等因素开展了研究。结果表明:在不同的掺混流量和流速下,表现出4种不同的流动模式,流动模式决定了贮箱内流动、换热及相变的趋势,掺混剧烈的流动模式压力下降快,较低的掺混温度对推进剂品质的提升有积极意义。

In order to investigate the characteristic of the axial-jet mixing,a CFD model is developed and checked with a NASA experiment on ground.Different mass flow rate,velocity,temperatue and inlet diameters are been considered to research for axial-jet mixing flow.In different mass flow rate and velocity,the axial-jet flow can be divided into four flow patterns,which leads to different flow,phase change and heat transfer results.A higher mixing pattern makes a higher pressure decrease rate,and a lower temperature can improve the propellant quality.