预冷发动机进气道节流特性数值研究

Numerical investigation on throttle characteristics of precooled engine inlets

为了研究预冷发动机进气道预冷前后的节流特性,以二维轴对称进气道为对象,使用多孔介质耦合源项法进行数值仿真研究,在不同涡轮通道流量系数的工况下对比了预冷效果和进气道预冷前后的气动性能。研究表明:随着涡轮通道流量系数增加,亚声速扩压段锥面压力降低,虚拟预冷区下游低速区面积缩小,而两通道出口总压恢复系数均呈下降趋势,同时涡轮通道流量系数较高的工况冷却效果更好;冲压通道出口总温受预冷区影响而下降,高速工况下降幅度较大,但下降幅度不受涡轮通道出口流量系数影响;相同涡轮通道流量系数的高速工况,经过预冷后涡轮通道流通能力增强。

In order to study the throttle characteristics of the precooled engine inlet before and after precooling, the two-dimensional axisymmetric inlet was used as the object, and the porous medium coupled source term method was used to conduct numerical simulation research. Under different working conditions, the precooling effect and the aerodynamic performance before and after precooling were compared. Studies indicated that when the mass-flow-ratio of turbine channel increased, the cone surface pressure of the subsonic diffuser section decreased, the area of the low-velocity zone decreased, the coefficients of total pressure recovery of both outlets showed a downward trend, and the precooling effect of the turbine channel was better. The total temperature of the outlet of the ramjet channel was also reduced by the influence of the precooler, and the degree of decline at high-velocity conditions was larger, but the degree of decline was not affected by the mass-flow-ratio of the turbine channel. In the high-velocity working condition of the same mass-flow-ratio of turbine channel, the turbine channel flow capacity was enhanced after precooling.