预冷对发动机进气道流动特性影响的数值模拟研究

Numerical Simulation Study of Effects of Precooling on Flow Characteristics of Engine Inlets

关键词:  SABRE进气道  数值仿真  源项  多孔介质  预冷  压降

Key words:  SABRE inlet  Numerical simulation  Source term  Porous media  Precooling  Pressure drop

摘要:

为了研究预冷对协同吸气式火箭发动机（Synergetic Air-Breathing Rocket Engine，SABRE）进气道流场性能的影响，以各工况临界状态下无预冷的SABRE发动机进气道为对象，结合多孔介质耦合源项法开展了预冷效应对进气道流动特性影响的数值仿真研究。对比了预冷前后进气道流场及气动性能的变化。研究表明，多孔介质耦合源项法预冷可以较好地模拟预冷器的冷却效应及压降效应，预冷后结尾激波较预冷前向前移动了一段距离，各工况涡轮通道出口总温降低了48%~77%，其中Ma2~4时总温降低到了210K左右；来流空气经预冷后涡轮通道出口马赫数降低，流量系数也随之降低；进气道总压恢复系数呈减小趋势，低速工况总压恢复系数较好，预冷前后两通道总压恢复系数变化不大，涡轮通道流量系数较预冷前降低了约15%。

Abstract:

To study the precooling effect and flow field performance of synergetic air-breathing rocket engine (SABRE) inlet，the SABRE engine inlet without precooling under critical state of each working condition was adopted，and a numerical simulation study of the effects of precooling on the flow characteristics of inlet was carried out in combination with porous media coupling source term. The change of aerodynamic performance of inlet before and after precooling was compared，and the effect of airflow on inlet performance after precooling was explored. Studies indicate that porous media coupled source term method could commendably simulate the cooling effect and pressure drop effect of precooler and the terminal shock wave moves forward a distance after precooling. The total temperature of turbine channel outlet under each working condition decreases by 48%~77%，among which the total temperature at Ma2~4 reduces to around 210K. After precooling the incoming air，the exit Mach number of turbine channel is reduced，and its mass flow ratio also decreases accordingly. The inlet total pressure recovery coefficient tends to decrease，and it is better at low speed condition. The change of total pressure recovery coefficient of the two channels before and after precooling is not obvious. Mass flow ratio of turbine channel is approximately 15% lower than that without precooling.