基于Lagrange液膜方法的小推力液体火箭发动机耦合传热策略研究

Coupling Heat Transfer Strategy for Small Thrust Liquid Rocket Engine Based on Lagrange Film Method

关键词:  耦合传热  Lagrange方法  数值仿真  冷却

Key words:  Coupling heat transfer  Lagrange method  Simulation  Cooling

摘要:

为了研究小推力液体火箭发动机边区冷却液膜的冷却效果，提出了一种综合考虑燃烧流动、气体辐射、液膜冷却、壁面传热和辐射冷却的耦合传热计算方法，构建了基于Lagrange方法的液膜计算模型。采用该耦合传热方法对490N液体火箭发动机进行了数值仿真研究。结果表明:液膜最大厚度60μm，最长30mm，覆盖区域的壁面温度都被限制在420K左右，起到了较好的冷却作用。喷注角度较小射流形成的液膜更集中，生存时间更长，可减小向壁面的热流；喷注角度较大射流形成的液膜周向范围更大，能缓解壁面热流向头部的传递。

Abstract:

To research cooling effects of the film formed by small thrust liquid rocket engine’s border nozzle， a coupling heat transfer method which considers the combustion flowing， gas radiation， liquid film cooling， structure heat transfer and radiation cooling was proposed， then a series of liquid film calculating model using Lagrange method were set up. A 490N liquid rocket engine was simulated using this coupling heat transfer method. The results show that the largest film’s thickness is 60μm. The longest liquid film’s length is 30mm. The temperature of the wall covered by liquid film is limited to about 420K， so the liquid film has an expected cooling effect. The film formed by the smaller angle of the injection panel is compacter with the longer survival time， which prevents the central heat transfer to the structure effectively. The larger angel film has a greater circumferential range， which relieves the heat transfer from the structure to the head.