预冷空气涡轮火箭发动机氦循环系统的参数特性

Characteristic of helium cycle system parameters for pre-cooling air turbo rocket engine

针对预冷空气涡轮火箭发动机(PATR)方案,建立氦循环系统数学模型,模型考虑组件结构特征、几何尺寸、工质物性等主要因素。数值计算表明:PATR的推力和比冲性能较优,模型可描述发动机氦循环热力过程,其中发动机余气系数是影响发动机推力、比冲的关键参数。提高氦循环系统最高设计压力和降低空气预冷器氦进口温度可有效降低压力损失和氦压气机功率,最高压力每增大1MPa,系统平均压力损失下降1.1%,氦压气机输入功率下降3.2%;空气预冷器氦进口温度每升高1K,系统平均压力损失上升0.086%,氦压气机输入功率升高2.3%。

Pre-cooling air turbo rocket engine（PATR）is a typical scheme.A mathematical model of helium cycle system for PATR was established by considering the main factors,such as the structural features of components,geometry dimensions and working fluid properties.Numerical simulation showed that the thrust and specific impulse of PATR simulation were better,and the model could describe the thermodynamic process of helium cycle.In addition,the excess air coefficient of engine was a key parameter affecting the engine thrust and specific impulse significantly.Analysis results indicate that improving the highest pressure in helium system and decreasing the inlet helium temperature in air pre-cooler are effective methods to reduce the system pressure loss and helium compressor power.For every increase of the highest pressure with 1 MPa,the average system pressure loss and the helium compressor power decreased 1.1% and 3.2%,respectively.Similarly,for every increase of air pre-cooler inlet helium temperature with 1 K,the average system pressure loss and helium compressor power increased 0.086% and 2.3%,respectively.