Numerical Investigation of the Flow Dynamics Inside Supersonic Fluid Ejector

摘要

This paper describes the flow dynamics inside a supersonic ejector using CFD modelling. Suitable ejector geometry isproposed for the high compression ratios encountered in real-world applications. Post-processing and physical analysis ofthe CFD results are presented to better understand the entrainment mechanism and the mixing between the primary andthe secondary fluids. The effect of the primary pressure on the flow dynamics and the entrainment ratio is discussed for thetwo compression ratios of 1.67 and 3.4. It is found that the proposed ejector can operate at compression ratio as high as 3.4.It is also found that the strength of the shock waves, the supersonic jet expansion and the mixing between the primary andsecondary fluid flows inside the ejector are strongly affected by the primary pressure. A significant increase in both the shearforces amplitude and the wall friction losses is observed when the boundary layer separates from the ejector wall.