Aerodynamic Optimization Of Three-Dimensional Impeller Blades In Centrifugal Compressor

Centrifugal compressor plays an important role in energy consumption and conversion in industry.Improving the aerodynamic performance of its impeller is of great significance to improve the energy conversion rate,energy saving and emission reduction.In this thesis,a threeway impeller developed by an enterprise in Shenyang is taken as the research object.Firstly,Bézier mathematical curves are used to control the multi-structure Parameters that affect the aerodynamic performance of the impeller,so as to realize the geometric modeling Parameterization of the impeller,and then complete the aerodynamic optimization of the impeller’s meridian plane and three-dimensional blades,so as to further improve the isentropy efficiency and compression ratio on the basis of the original impeller,and then the aerodynamic performance of the impeller is improved.The main research contents are as follows:(1)In order to realize the flexible control of impeller shape,starting from geometric description,Bézier mathematical curve was used to Parameterize the loading curve of threedimensional blade Angle with the help of geometric relationship between blade Angle and circumferential Angle.The problem of mutual restriction of impeller structural Parameters is coordinated,the comprehensive influence of structural Parameters on aerodynamic performance of impeller is coordinated,and then the geometric modeling Parameterization of impeller is realized.(2)Single factor aerodynamic research was carried out on the four positions of impeller meridian surface,three-dimensional blade shroud inlet,shroud outlet,hub inlet and hub outlet.Through numerical simulation,it is found that the three-dimensional blade has more influence on the aerodynamic performance of the impeller than the meridional surface.The isentropic efficiency and pressure ratio of the impeller increase first and then decrease with the unidirectional change of the shape and position of the leading edge,and the maximum point appears.With the unidirectional change of the shape and position of the trailing edge of the blade,the overall trend is downward.(3)Based on the single factor optimization,the influence of the interaction of the four positions of the three-dimensional blade on the aerodynamic performance of the impeller was further considered,that is,the three-dimensional blade was optimized with multi-factor coupling.Combined with the experimental design,BP artificial neural network and genetic algorithm,the impeller with the best aerodynamic performance was obtained.The research shows that,under the design condition,after multi-factor coupling optimization,the impeller pressure ratio increases by 15.5%,isentropic efficiency increases by 1.9%,and the aerodynamic performance of the impeller is greatly improved;The actual simulation value of the optimization evaluation function is 95.23%,which is 0.4% higher than that predicted by the neural network prediction model,and the prediction model is accurate.Through the research work of this thesis,the isentropic efficiency and compression ratio of the impeller are comprehensively improved,and the aerodynamic performance of the impeller is improved,which has positive significance for energy saving and emission reduction.