Experimental and numerical simulation study on the application of ejector pumping theory of aero-engine in aircraft laboratory

Abstract

The smooth discharge of engine exhaust gas is important in accurately simulating aircraft laboratory climate test environments. In this study, a three-dimensional transonic engine exhaust ejector model is developed by considering the phenomenon of supersonic airflow fluctuation, the theory of airflow ejection, and the choking effect. Compressible numerical solution theory is used to calculate the overall performance and internal flow of the ejector, and the effects of geometrical and operational parameters are analyzed to reveal the operational mechanisms of the engine ejector choke discharge in the aircraft laboratory. Finally, the accuracy of the numerical model is verified experimentally. The results show that the choke effect occurs when the entrainment ratio increases linearly with the throat diameter, the nozzle exit position (NXP) is outside the pipe, and the discharge pressure is less than the critical pressure.