The experimental research and mechanism analysis on the influence of wave rotor rotational speed on the wave system and flow losses of gas wave ejector

摘要

Gas wave ejector (GWE) is an efficient injection and supercharging device. The rotational speed of wave rotor is an important parameter affecting the equipment performance. The influence of rotational speed on device performance was intensively studied by experiments and numerical simulations. The results suggest that there is an optimal speed to optimize the equipment performance with fixed pressure ports. Redundant compression waves are generated destroying the ideal wave system when the speed deviates from the optimal value. And the performance reduction induced by these redundant waves is different since the pressure, initial pressure ratio and reversed pressure ratio in the passages of stable pressure region are different in different working conditions. In addition, increasing rotational speed to a certain extent can reduce various types of loss in the passages. However, the viscous dissipation increases sharply if the speed is high enough. The propagation speed of shock wave increases with the increase of rotational speed, which should be taken for granted when designing the geometries of pressure ports. In the experimental conditions, the highest isentropic efficiency and ejection rate GWE can reach about 60% and 80% respectively in the experiments of this paper.