Experimental and numerical research on flow characteristics of inlet particle separator for aero-engine under the influence of water film

Abstract

An aero-engine must be able to operate in all-weather conditions, which requires the aircraft to be safe throughout the flight even in bad weather. Excessive intake of rainwater can induce stall and surge of compressor and flameout of combustion chamber, which will lead to the loss of power of the engine. In rainy weather, water come into the engine inlet protection device, which directly determines the compressor inlet conditions and will further affect the compressor working condition and the matching features. In this paper, special attention was paid to the experimental characteristics of aero turbo-shaft engine inlet particle separator (IPS) and the numerical study employing ANSYS-CFX under water spraying condition. Based on the phenomenon of water film forming on the wall surface of the IPS and the experimental data under different water spraying conditions, combined with the predictions from CFD study, an empirical model of water film flow on the wall surface has been developed. The results indicate that in the case of high water ingestion, droplets will inevitably form water film on the wall after entering the IPS. Due to the viscous resistance of wall water film and its influence on the airflow boundary layer, the flow state inside the IPS will change. By establishing a wet wall water film model, the flow characteristics near the wall are closer to the experimental state. The total pressure loss prediction error was reduced from 24.8% to 5.2% and 26.4% to 5.7% under the uniform water spraying rate of 2.93% and 4.84%, respectively.