非预混条件下的旋转爆轰燃烧室双波头演化过程数值模拟

针对旋转爆轰燃烧室双波头演化过程中流场结构变化的问题,对非预混条件下的旋转爆轰燃烧室从起爆到形成稳定的双波头过程进行了数值模拟研究。研究结果表明,从起爆到形成稳定爆轰过程,燃烧室主要经历了起爆、爆轰波对撞和稳定爆轰三个阶段；在爆轰波对撞阶段,首次对撞是两个爆轰波间的对撞,由于对撞点处缺少新鲜混合气,从而在对撞结束后衰减为两个压力波。第二次对撞是两个压力波间的对撞,因为在第二次对撞点附近存在新鲜混合气来支撑爆轰波的持续传播,故对撞结束后产生了一个爆轰波和一个较弱的压力波；第二次对撞发生后,燃烧室内的压力波反射叠加并形成局部高压区,此高压区压缩气体使气体温度升高,高温气体引燃混合气后,最终发展成为第二个爆轰波；稳定阶段,两个爆轰波均能稳定自持传播,爆轰波峰面压力可达1.45MPa,波后温度为2500K,爆轰波速度稳定在1738m/s,产生的推力与比冲分别为79.76N和2312.15s；斜激波的存在使燃烧室出口平面流场产生了较大波动。 

Numerical study on the two-wave transition process in rotating detonation combustor under separate injection condition

In order to analyze the flow field structure of the two-waves evolution in the rotating detonation engine, a numerical simulation was conducted to investigate the formation process of two detonation waves under the separate injection condition. The results showed that from ignition to stable detonation, three phases including ignition phase, collision phase and stable phase, were included in the process. The first collision happened in two detonation waves, but two pressure waves were formed due to lack of fresh mixed gas around the collision zone. Then, the second collision happened in two pressure waves.As a result,the detonation wave and shock wave were formed due to the existence of mixed gas around the second collision zone. After the second collision, a high pressure zone was formed due to the pressure wave reflection and overlay, then the gas was compressed by the high pressure zone and the temperature of the gas was increased, the high temperature gas ignited the fresh mixed gas, finally, the second detonation wave was formed. When the detonation wave was stable, the wave pressure reached 1.45MPa, the temperature was 2500K, and the velocity was 1738m/s. Besides, the thrust on the outlet was 79.76N and the specific impulse was 2312.15s.A significant fluctuation was created by oblique shock wave on the outlet.