ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2022, Vol. 43 ›› Issue (9): 126024-126024.

• Fluid Mechanics and Flight Mechanics •

### Wet compression performance and flow characteristics of transonic compressor

AN Liping1,2, WANG Hao1, WANG Yangang1, ZHU Zihuan1

1. 1. School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China;
2. AECC Sichuan Gas Turbine Establishment, Chengdu 610500, China
• Received:2021-06-25 Revised:2021-07-20 Online:2022-09-15 Published:2021-09-08
• Supported by:
National Natural Science Foundation of China (51906205); Natural Science Basic Research Plan in Shaanxi Province (2019JQ-620)

Abstract: In this paper, the CFD technology combined with Euler-Lagrange method is used to simulate the gas-liquid flow field in a transonic compressor under inlet uniform fogging. The influence of different fogging conditions (droplet size and spray flow rate) on performance and stability boundary of the compressor is studied. The mechanism of performance variation is explained by the change of rotor inlet/outlet velocity triangle, specific work and process lines on temperature-entropy diagram. The results show that wet compression can improve the pressure ratio and efficiency of the compressor. However, the influence of wet compression on power consumption of the compressor has different trend under different comparison conditions. Under the condition of equal mass flow, wet compression can increase the specific work, while under the condition of equal pressure ratio, wet compression can reduce the specific work. The stall flow rate increases after fogging, and the increase degree of stall flow rate is positively correlated with the rise of pressure ratio. Under the condition of equal flow rate, the evaporative and cooling effect of the droplet can reduce the temperature of the air flow at outlet, causing increase of air density and decrease of axial velocity, and finally leading to the enhancement of the torsion speed and the specific work of the rotor. This is the main reason for the rise of compressor stage pressure ratio under the condition of equal flow rate. In addition, the smaller the droplet size is, the more significant the evaporative cooling effect is, and the stronger the effect of improving the compressor pressure ratio and power consumption is. Large droplets have weak evaporative cooling effect and strong droplet breakup effect, which will bring additional flow loss and reduce compressor efficiency.

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