RBCC发动机超燃/火箭模式流场数值模拟研究

Numerical Simulations on RBCC Engine in Scramjet/Rocket Mode

关键词:  火箭基组合动力循环  超燃/火箭  支板火箭  流量  数值模拟 

Key words:  Rocket-based combined cycle  Scramjet/Rocket  Strut-rocket  Mass flow  Numerical simulation

摘要:

针对进排气系统与燃烧室匹配工作的中心支板式火箭基组合动力循环(RBCC)发动机,通过数值模拟研究了RBCC发动机在低动压、高速高空域飞行条件下以超燃/火箭模式工作时的燃烧流场特征,并分析了支板火箭喷管出口流量的变化对燃烧流场的影响。结果表明:在超燃/火箭模式下,支板火箭工作能促进燃料与空气的掺混燃烧,实现发动机稳定工作,同时可提升发动机的推力性能；随着支板火箭流量的增加,发动机产生的总推力逐渐增大,总推力与火箭流量大小近似成正比；随着火箭流量的增加,燃烧室中的流动状态向以超声速流动占主导地位发展,进气道的抗反压能力得到提升。 

Abstract:

Under the conditions of low dynamic pressure, high velocity and high flight altitude, numerical simulations were carried out to analyze the flowfield characteristics of rocket-based combined cycle (RBCC) engine in the Scramjet/rocket mode, which was composed of a combustor matched with an appropriate inlet and exhaust system. The effects of the variations of the strut-rocket mass flowrate at the exit of the nozzle on the combustion flow were also investigated. The results show that in Scramjet/rocket mode, the operation of strut-rocket can enhance the mixing and combustion between fuel and air, realize the steady operation of engine, while promoting the thrust performance. The total thrust of the engine increases gradually with the increment of the strut-rocket mass flowrate, which is proportional to the rocket mass flowrate approximately. The flow condition in the combustor develops towards the flow dominated by supersonic, and the resistance pressure ability of the inlet improves as the rocket flowrate increases. 