Numerical Investigation on the Influence of Wet Compression Aerodynamic Performance of Multi-Stage Transonic Compressor

Abstract In this paper, the gas-liquid two-phase flow in a multistage transonic compressor was numerically simulated based on the Euler-Lagrange method. The influence of wet compression aerodynamic characteristics of the compressor was investigated under different spraying conditions (spraying rates and droplet sizes). The results indicated that the compressor choking boundary moves to a smaller flow rate after spraying. Wet compression improves efficiency of the compressor. The evaporation cooling effect of wet compression decreases total temperature ratio and increases the specific power, resulting in the promotion of the total pressure ratio. After the water droplets are injected into the compressor, due to the small rise of the airflow temperature in the first stage area, the evaporation cooling effect of droplets is weak. Negative effects of droplets lead to a decreasing in the first-stage pressure ratio after spraying. As water droplets move downstream, the gradual increase in airflow temperature enhances the evaporation cooling effect, thereby improving the compressor performance. Water droplets migrate radially inside the compressor and gather toward the blade tip area, causing the gas phase mass flow inside the compressor to be redistributed in the radial direction. Wet compression leads to an increase in the compressor twist velocity, enhancing the capability of the rotor blades to perform work on airflow.