Influence of Gas Medium State Parameters on the Pressure Port Design of Gas Wave Ejector

The objective of this study is to explore and emphasize the influence mechanism and law of gas parameters on pressure port design. CFD commercial software FLUENT was used for numerical simulation in this study, and a three-dimensional numerical model was employed to improve the accuracy of calculation. The GWE experimental platform was also built to verify the theoretical and numerical analysis results. When the expansion ratio α is raised from 1.35 to 2.0, the average shock velocity vs can increase by about 4.9%, and when raising the compression ratio from 1.05 to 1.2, the change of vs is only 1.4% relatively. Raising the expansion ratio value from 1.35 to 2.0, the optimal offset of the high- and medium-pressure ports only changes by 5.3%, and the decrease of the ejection rate caused by the deviation of the aforementioned offset is only about 4.3%,which proves that the equipment has strong ability to resist fluctuations of working conditions. Moving velocity of the shock wave varies with temperature, working pressure ratio and adiabatic index of the gas. The increase of high- and low-pressure inlet gas temperatures will cause an increment of vs and as, and the influence of high-pressure inlet gas temperature Tht on vs is greater. There are optimal high- and medium-pressure port offsets under different pressure ratios as the experimental results have shown. When the pressure ratio remains constant, the change in pressure value does not have a significant impact on the optimal port design and equipment performance.