Investigation On Injection-Mixing And Operating Process Of Continuous Rotating Detonation Engine

Rotating detonation engine?RDE? uses detonation to organize combustiuon and has a high thermal cycle efficiency. In contrast to PDE, once the RDE is initiated, the engine can operate continuously and has a higher operating frequency. And the configuration of RDE is simple and compact, thus it can be designed to have lower weight. Therefore, the investigation of RDE has become a hotspot of supersonic propulsion. By numerical simulation and experimental study, this paper systemly investigated the injection- mixing and operating process in RDE.In the operating process of RDE, the mixing effect of fuel and oxygen is a key point that affects combustion flowfield and engine performance. In this paper, three-dimensional numerical simulations are carried out to investigate some factors that have influence on mixing process. The results show that for hole-slot injection, as the fuel inject pressure gets larger and injection angle gets smaller, the mixing efficiency along the axis gets lower; when the whole injection area remains the same, mixing efficiency gets larger as the number of injection holes gets bigger. Besides, hole-hole and hole-slot-hole injection method are also investigated, and their comparations with hole-slot are carried out.Two-dimensional numerical simulation is carried out to investigate the operating process and the influence of equivalence ratio and injection pressure on the performance of RDE. The investigation shows that under present pressure condition, to sustain the propagation of the detonation wave, the equivalence ratio must be no less than 0.7. When the equivalence ratio is 1.1, the engine has the best performance; to sustain detonation wave propagating continuously, the pressure of premixed gas has lower limit and upper limit; as the injection pressure increased, the instability of detonation propagation also get larger.A RDE model that can realize various methods of mixing is designed in this paper. Many combinations of fuel/oxidizer are tested, such as H₂/Air and H₂/O₂. Pressure analysis is mainly used to do the investigation. The influence of equivalence ratio and injection pressure on the operating process of RDE is investigated. Comparing analysis of different injection method is carried out. The results show that: the increasing of equivalence ratio properly is useful to increase the pressure in combustion chamber; the mixing efficiency of inner-injection is higher than outer-injection; the increase of mass flow rate can efficiently increase the combustion chamber pressure and then beneficial to achieve better performance; based on CH₄/O₂/Air, PCB data is analysized to get the frequency and propagation velocity of the detonation wave.