An Experimental Comparative Performance Study of Variable Area Ejectors in Different Operating Conditions

Abstract

Abstract This research experimentally compares the performance of two variable area ejectors designed based on the Constant Rate of Momentum Change (CRMC) approach and the Constant Rate of Kinetic Energy Change (CRKEC) approach. Ejector systems were designed for specific design and operating conditions to perform experiments. The pressure recovery ratio (PRR) and entrainment ratio (ω) at on-design operating conditions were compared using the experimental results. The study also optimized the entrainment ratio of both systems at off-design conditions. The results indicate that both variable-area ejectors based on CRMC and CRKEC have their own advantages and limitations in terms of performance and suitability for specific applications. CRMC ejectors provide higher entrainment ratios (0.512) and lower pressure recovery ratios (0.178), while CRKEC ejectors provide slightly higher pressure recovery ratios (0.18) and lower entrainment ratios (0.5) at on-design conditions. Furthermore, the study investigated the off-design impact of nozzle exit positions (NXPs) and the pressure of motive and secondary flows on the entrainment ratio of both ejectors.