轴流压气机吸雨特性的数值研究

Numerical Research of Water Ingestion Effect on Axial Flow Compressor

航空发动机在吞雨工况下的运行安全及稳定性是亟待解决的重要问题。雨水的吸入改变了发动机的工作特性,影响发动机稳定性,为了探究液态水吸入对航空发动机压缩部件性能的影响规律,本文基于CFD软件平台,对单级轴流压气机的吞水过程进行了三维数值模拟研究。研究过程考虑了液滴蒸发、颗粒气动及撞击破碎等方面的影响,分析了不同吸雨工况对压气机性能的影响。结果表明,液态水的吸入可导致压气机流量、压比和效率的降低,且性能恶化程度随着吸雨量的增大而增大;压气机扭矩的增加与吸雨量成正比;液态水的吸入使得吸力面气流分离区域向前缘移动,叶背附面层损失增大,叶栅通流能力降低;大颗粒水滴在单级压气机中的蒸发作用并不显著,蒸发效果对压缩性能影响不大。

The safety and stability of aero-engine operation under the condition of swallowing rain is an important problem to be solved urgently.The suction of rainwater changes the working characteristics of the engine and affects its stability.In order to investigate the influence of water ingestion on the performance of engine,3-D numerical simulation of the singlestage axial-flow compressor NASA Stage35 with water ingestion was conducted based on CFD.Considering the water evaporation,water droplets breakup,droplet-wall interaction.The effect of different water ingestion quantities on the compressor performance is analyzed.The results show water ingestion is caused by a decrease of mass flow,total pressure ratio and efficiency and the degree of performance degradation increases with increasing the water ingestion quantity.The compressor torque increases is proportional to the quantity of water ingestion while water ingestion makes the flow separation region on blade suction surface moving forward to leading edge which increases the layer loss of suction surface and decreases cascade flow capability.And the evaporation of large water droplets in a single stage compressor is not obvious.