Impact of Air System Bleeding on Aircraft Engine Performance

Air system bleeding is indispensable to aircraft engines despite its negative impact on the engine thrust and the fuel consumption. However, the compressor performance can be improved if the bleeding design is optimized. The model in this paper is a one-dimensional engine model based on air system bleeding. The relation between the compressor performance and the engine thermodynamic cycle caused by bleeding is analyzed to explore the potential of air system bleeding in improving compressor and engine performance. The results show that if bleeding brings an increase the pressure ratio of compressor, the negative impact on engine specific fuel consumption can be inhibited. If the efficiency of compressor is increased after bleeding, the negative impact on engine thrust can be alleviated. With proper bleeding flow rates, if both the pressure ratio and the efficiency increase at the same time, the negative impact on the engine performance can be eliminated.