Experimental investigation of a novel variable geometry radial ejector

Abstract

This work focuses on improving ejector performance in variable conditions by developing a radial flow variable geometry radial ejector (VGRE). The research objective was to demonstrate the performance of the improved VGRE, which can operate more effectively under changing operating conditions compared to a fixed geometry design. The improved VGRE was developed and experimentally tested to enable adjustment of the nozzle and ejector throat areas to suit different ejector operating conditions in various applications. Radial ejectors have a smaller size than axial ejectors, which is a significant advantage in some applications. Results showed that the improved VGRE achieved higher entrainment ratio and critical compression ratio compared to a fixed geometry design and that optimal performance was obtained with nozzle and duct throat separations of 0.5 mm and 3.0 mm, respectively. The results also indicated that the wall static pressure in the throat region of the improved VGRE was similar to that observed in conventional axial ejectors and showed an average improvement of 107 % in entrainment ratio and 76 % in critical compression ratio relative to previous studies of air ejectors. The findings suggest that the improved VGRE concept could be applied to a wide range of applications in the future.