Aerodynamic Analysis And Design Optimization Of Centrifugal Compressor Impeller

Centrifugal compressor,as the core component of turbo compressor,has an important influence on its performance.It has been one of the hottest research issues to design a compact centrifugal compressor with high pressure ratio and high efficiency.Because of the complex flow inside the centrifugal compressor,the design cycle of the high performance compressor based on experience and trial and error mode is long and the design difficulty is high.With the development of computer technology and computational fluid dynamics(CFD)technology,the optimization design method based on 3D CFD technology has been applied in the field of compressor technology.In order to find a fast and efficient method based on the analysis of the internal flow field,the influence of the compressor performance parameters,taking a vehicular centrifugal compressor impeller as the research object,the analysis and optimization method combining the Kriging model and the research of multi-objective genetic algorithm,based on the study of three-dimensional flow field analysis,multi-objective optimization for high efficiency and high pressure ratio is conducted in this paper.The main contents of this paper are as follows:First,according to the basic performance parameters and design parameters of a gasoline engine,the turbocharger matching calculation and thermodynamic calculation are carried out,and the MATLAB program is compiled;Based on the design theory of the compressor impeller,the centrifugal compressor is designed and the 3D model of the impeller is established.Second,the approach of CFD numerical simulation based on the Navier-Stokes equation is employed,a three-dimensional numerical simulation model for the aerodynamic performance analysis of the centrifugal compressor impeller is established;taking the NASA LSCC impeller and SRV2-O centrifugal impeller as object,the impeller performance curve and the internal flow characteristic such as flow pressure and velocity field,the tip clearance flow are researched,Comparing the calculated results with the experimental results,the applicability of the numerical analysis method is validated.Third,based on the three dimensional flow field analysis,the influences of the design parameters,such as the inlet blade angle,the outlet blade width,the outlet blade angle,the circumferential position of the splitter blade,the blade tip clearance and the blade envelope angle on the performance of the impeller are studied.The Latin hypercube design method is used to in the experimental design of the compressor parameters,and the sensitivity analysisof design parameters is carried out.Based on the results of the experimental design and three-dimensional flow field analysis,the Kriging model is built and the accuracy of the model is analyzed.Fourth,based on the Kriging model,the NSGA-? algorithm is used to optimize the compressor impeller with the objective of high efficiency and high pressure ratio.The Pareto solution set is obtained,the results show that the efficiency of the designed impeller is improved by 4.23% and the pressure ratio is increased by a factor of 4.39% compared with the preliminary impeller,at the same time,the internal flow and the overall performance at different working conditions have been improved,and the stale operation range has been enhanced.