A theoretical model for performance evaluation of a novel configuration of supersonic ejectors

Abstract

Few researches have investigated on the improvement of supersonic ejector configuration. This paper presents a theoretical model for evaluating the performance of a novel supersonic ejector configuration that has not been investigated before. Under various geometry parameters and operating conditions, the working performance of ejectors in conventional and novel configurations is investigated. In addition, the performance characteristics of the novel configuration were analyzed, and the Kantrowitz limit was introduced to obtain a reference value for the compression surface radius on a theoretical basis. 24 ejectors with different geometry parameters, including the conventional and novel ejectors, are designed and tested using CFD approach. The results show that the performance of the novel ejectors is better than that of the conventional ejectors within the deterioration point, and the trend of their critical outlet pressure is consistent with the theoretical model. Moreover, the deterioration point is well predicted, and the performance of the novel configuration decreases when the compression surface radius exceeds the deterioration point. Last, the relationship between the flow field and key parameters of the novel configuration was illustrated by analyzing the Mach number contours and pressure distribution of the conventional and novel ejectors.