INVESTIGATION OF SUPERSONIC AIR EJECTROS - 2. EFFECTS OF THROAT-AREA-RATIO ON EJECTOR PERFORMANCE.

Abstract

The performance of a supersonic air ejector was experimentally studied over a range of ejector-to-nozzle throat-area-ratios psi and primary nozzle Mach numbers M//1//p. The investigations covered both straight-tube and second-throat ejector types. As the result, the effects of the ratio psi on the ejector performance were made clear. The performance curves were classified into five groups by the values of psi and a primary chamber-to-ambient pressure ratio P//o//p/P//a. For a fixed psi , an optimum P//o//p/P//a exists which realizes a maximum secondary flow rate and a minimum secondary chamber pressure. Also, for a fixed M//1//p, the optimum P//o//p/P//a becomes minimum at a certain psi , which was defined as an optimum throat-area-ratio. The physical meanings of the optimum pressure ratio and the optimum throat-area-ratio were clarified using the results of pressure measurements and optical observations.