Numerical Analysis Of The Aerodynamic Performance For A Transonic Compressor Rotor With Inlet Fogging

The modern axial compressor developing into high stage pressure ratio, high blade load and high tip velocity, the problem of stable operation becomes very important. Generally, the high stage pressure ratio or high blade load will result in a transonic stage, especially the front stage of a compressor. It is always try to find a way to extend the range of stable operation, to keep the high efficiency at the same time, and to make the compressor work safely and economically. There are several techniques available for extending the range of stable operation, such as rotating the stator vane, extracting compressed air in the middle stage and casing treatment. Air injection in the blade tip area of a compressor is one of the techniques to improve the stable operation of compressor, which has been improved. Water injection could be another way to help to extend the stable operating range of compressor.Wet compression technology in the compressor are imported or in the compression process to the compressed gas injected into liquid, the use of liquid absorbs heat of vaporization, to reduce the compression power, increased output power, thereby improving the gas turbine performance. But all the researched compressors is subsonic, there is no research on transonic compressor. So in this Paper, the point is to investigate the effects of wet compression on a transonic compressor performance and stall.In this Paper, a full 3-D steady numerical simulation is carried out under different conditions. Different injected water flow rates and droplet diameters have been considered in this Paper. This Paper mainly investigates the effect of wet compression on the shock, the separated flow, pressure ratio and efficiency. Besides, it emphasizes the effect of wet compression on the tip clearance when the compressor runs near-stall and stall situation. The analysis of the results shows that 1 micron can not improve the inlet flow rate and the pressure ratio. But when the diameter is above 5 micron, the range of stable operating is extended, and the pressure ratio and the inlet air flow rate also increase at the near-stall point. In addition, it seems that there is an optimum size of the droplet diameter and injected water flow rate.