Influence of wet compression on performance of compressor rotor working at its stall boundary

At the stall boundary condition of a transonic compressor rotor, numerical simulation method was used to study the effects on operation performance with different inlet fogging conditions. Correlation curves between performance parameters, including air flow, total pressure ratio, isentropic efficiency and specific work, and inlet fogging parameters, including water droplet diameter, velocity, temperature and water spray rate, were obtained. Results showed that inlet fogging can increase air flow, heighten total pressure ratio, enhance isentropic efficiency and reduce specific work. Through analyzing the flow field in detail, it was found that inlet fogging can inject high momentum water droplet to tip stagnation zone, decrease blockage region, move down the interface between main flow and leakage flow, weaken the strength of shock, reduce tip load and increase load at mainstream region. A parameter named water droplet area flow was taken to evaluate the effect on flow field with different fogging conditions quantitatively.