The Numerical Simulation Of Inlet Fogging Effects On A Transonic Stage

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 and has been a focus in the field of compressor during these years. Recently, all the research is about the subsonic compressors, so in this Paper, the point is to investigate the effects of inlet fogging on a transonic compressor performance.On the basis of the numerical simulation theories, the geometrical model and computational grids are built with Turbo grid of a NASA transonic compressor stage-Stage 35 in this dissertation. Besides, with the simulation model of this transonic compressor, a full three-dimensional calculation of dry and wet compression under different operation conditions is conducted by utilizing Ansys-CFX. Under the conditions of different injected water flow rates and droplet diameters, we can observe the change of overall performance and flow field in this tansonic compressor stage. This paper mainly investigates the change of stall boundary and chocking boundary under different humidifying cases. At the stall boundary, it 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. At the chocking boundary, we also study the effect of wet compression on the pressure ratio, efficiency, outlet temperature and the separated flow of pressure surfaces.From the numerical simulation results, at the stall boundary, along with the increasing of injected water flow rates and the decreasing of droplet sizes, the effect in eliminating the tip clearance gap leakage is obvious; the analysis of results shows that 3μm and 5μm move their new stall boundary to the left compared to the dry case and the trendency of moving to the left reduced with the increasing of injected water flow rates, another point is expanding the scope of working. At the chocking boundary, humidifying reduces the pressure ratio and efficiency, and the chocking boundary after humidifying move left compared to the dry case. So the entire operating range is relatively narrow.