Study Of Numerical Simulation And Experimental Verification On Multistage Axial Flow Compressor

CFD numerical simulation is an important measure to understand the internal flow mechanism of the compressor,it is also used to optimize the design of the compressor structure so that finally improve its performance.However,at present,the calculation results obtained by numerical simulation are different from the actual flow field of the compressor.On one hand,because the internal flow of the compressor is very complicated,it is difficult for CFD to accurately predict the internal flow field details of the compressor.The development of CFD numerical simulation is limited by the lack of experimental data of the compressor flow field,the numerical results cannot be fully verified with the experimental results.On the other hand,the accuracy of the calculation results is affected by the calculation parameters.Using abundant experimental results to correct the CFD numerical simulation method and to discussing the influence on numerical simulation results of the compressor by setting different calculation parameters is of great significance to improve the reliability and accuracy of the numerical simulation of the compressor.Summarizing a set of reliable numerical simulation methods which also suitable for different multistage axial compressors can provide guidance for the future application of multistage axial compressor numerical simulation.The deficiencies of previous studies on the numerical simulation of compressors mainly existed in the following aspects: only one blade row or one compressor was studied,the conclusions lacked systematic and sufficient validation;the research on the influencing factors of numerical simulation results was relatively single,mainly focused on the turbulence model;neglecting the difference of numerical simulation ability among calculation methods at different operating points,and so on.In this paper,three low-speed axial compressors with abundant flow field experimental datas are taken as research objects,aiming at grid parameters(including the percentage of mid-flow cells,the number of points of tip clearance cells),turbulence models,differential schemes and fluid models),to carry out detailed calculation and analysis,and to compare and verify with the experimental results from three aspects: the overall characteristics of the compressor,the radial parameter distribution between the stages,and the details of the internal flow field of the compressor.The results show that the mesh with 70% of the mid-flow cells and 25 poins of the tip clearance cells has the most advantages in predicting the aerodynamic performance of compressor;SA model can predict the compressor stability boundary more accurately,while ke model can predict the characteristics and the details of the internal flow field of compressor at the design point;and the numerical simulation results obtained under the central difference scheme are the most reliable;the perfect gas model is more suitable for the working fluid used in the numerical simulation of compressor.