火箭/冲压组合发动机工作特性分析

为分析火箭/冲压组合发动机在不同工作模态下的工作特性,对其在没有二次补燃情况下的内流场进行了数值模拟和分析,结果表明:(1)在火箭引射模态,火箭发动机应尽可能工作在其设计状态;(2)为有利于掺混燃烧,在较低的高度、较高的速度下由引射模态转换到亚燃冲压模态可能比较好;(3)在亚燃冲压模态,火箭发动机以某种低工况工作对冲压发动机的点火和火焰稳定是极为有利的;(4)在纯火箭模态,进气道关闭与否对组合发动机的整体性能几乎没有影响;为了获得较高的性能,二次喷管应采用扩张通道。

Study on the characteristics of rocket/ramjet combined cycle engines

In order to analyze the characteristics of rocket/ramjet combined cycle engines, the inner flow of a rocket/ramjet combined cycle engine was simulated without second combustion. Resuits indicated that the rocket engine should work on designed condition in ejection mode. For better secondary mixing and combustion, transforming of ejection mode to ramjet mode should take place at lower altitude and higher velocity. In ramjet mode, working under low operation condition would help to ignite and flame holding. In rocket mode, inlet closed or not had little influence on performance of the combined cycle engine. The expand flow path of secondary nozzle should be used to improve engine performance.