Supersonic Flow Visualization Over Patented Rotors for a Novel Crypto-Steady Pressure Exchange Ejector Using Schlieren Photography

Abstract

The process of pressure exchange occurs where flows exchange mechanical energy through work of mutually exerted pressure forces at their interfaces. A novel ejector based on the concept of supersonic crypto-steady pressure exchange rather than the more energy dissipative turbulent entrainment phenomenon is being developed. To better understand the flow structures in context of the novel ejector, schlieren photography is being used as a flow visualizaton tool. The crypto-steady mode of pressure exchange can be achieved with rotors that enable the creating of psuedoblades and entrainment gullies by a primary supersonic fluid. The primary fluid can perform work on an entrained subsonic secondary fluid in a non-steady mode of fluid-fluid interaction. The primary fluid jets emanating from the rotor form a helical pattern whereby the secondary fluid becomes entrapped in the interstices of the helices. In the non-rotating case of the rotors, the voids between psuedoblades that create helical structure end up, providing entrainment gullies for the secondary fluid. In the rotating case, work is done by the expanding primary fluid on the secondary fluid by the pressure forces acting across the helical boundary between the two fluids. Crypto-steady pressure-exchange has the potential of providing society with a highly efficient means of compressing a low energy fluid through direct contact with a relatively high energy fluid, thereby circumventing the complexity and the energy dissipation associated with intervening machinery inherent in conventional compressors and turbulent mixing in ejectors. Global entropy can be calculated using steady inviscid two dimensional equations. The paper will report progress made by using schlieren photography on three patented rotors.