Influence Of Bump Modeling Methods On The Aerodynamic Performance Of Transonic Compressor Cascade

As one of the three major components of the gas turbine,the improvement of the performance of the compressor can further improve the power-to-weight/push-to-weight ratio of the gas turbine and reduce fuel consumption.One of the effective ways to improve the performance of the compressor is to increase the single-stage pressure ratio of the compressor,and realize higher stage loads in fewer stages.The commonly used method to increase the stage load is to increase the rotation speed of the rotor.This will increase the rotor tip tangential velocity.This will make Mach number of the tip of the blade reach the supersonic velocity.So shock waves can occur in transonic compressors and shock waves intensify the flow loss inside the compressor,so it is very important 'to study the shock wave inside the transonic compressor.First of all,In this paper,the cross-sectional profile of a 70%blade height of a transonic compressor rotor is taken as the research object,and use the Hicks-Henne function,CST parameterization method,Parsec method and polynomial interpolation function to construct the bump.The numerical simulation method is used to calculate the aerodynamic performance of the dump cascades with different modeling methods under design condition.Compared with the prototype cascades,it is found that the dump will generate weak compression waves on the windward surface,and the weak compression waves can play a role of pre-compression,reduce the flow direction pressure gradient,weaken the intensity of the incident shock wave and the reflected shock wave.As the initial position of the bump is postponed,the bump's ability to suppress separation increases,the ability to weaken the incident shock increases,and the weakening effect on the reflected shock continues to weaken.Secondly,under the design conditions,the cascades of bump with different heights was numerically calculated.The results show that when the height of the bulge is less than 0.01b,as the height of the bump increases,the control effect of the bump on the shock wave will also increase,but when the height of the bulge exceeds the range,the internal flow state of the cascade is more complicated,which will cause additional flow loss.Finally,the numerical simulation of the bump cascade with better parameters obtained under non-design parameters,it is found that the bump modeled by polynomial interpolation function has better applicability of different conditions,and it can also improve the wave structure and reduce flow loss well under non-design parameters;the bump constructed by the Parsec method can effectively.weaken the intensity of incident shock waves and reflected shock waves on the suction surface under the design of inflow conditions and variable impulse angle conditions,thereby reducing the flow loss of the cascade.But with the increase of the incoming Mach number,the ability of the bump to weaken the shock intensity and delay the flow separation is greatly reduced;The bump constructed by the CST parameterization method and the Hicks-Henne function can well reduce the shock-related losses of the cascade under the design flow parameters,but the ability to weaken the shock intensity under non-design parameters is weak,and even the total pressure loss will increase,and the adaptability is poor.