Studies on Shock Wave Structures in Supersonic Ejector and Its Influence on Ejector Performance

Supersonic ejectors are an economically feasible and environmentally friendly technology. Shock wave structures significantly affect the ejector performance. In the present work, the first shock wave structures in a supersonic ejector were analyzed with experimental and numerical methods. The experimental results by the Schlieren method were used to verify the accuracy of the numerical simulation results. Then the influence of the inlet pressure on the first shock wave structures inside the ejector was analyzed under critical operating conditions. The numerical simulation results showed that the dimensionless length and height of the first shock wave inside the ejector increase with the increase of the primary pressure and decrease with the increase of the secondary pressure. Meanwhile, the relationship between the performance of the ejector and the shock structures was established, the entrainment ratio is positively correlated with the first shock wave aspect ratio and has a good linear relationship. The results may be beneficial to reveal the ejector’s working mechanism and design high performance ejectors in the future.