Study Of Parameterization Design Method For Radial Turbomachinery

The geometric modeling of blades is a key step in the design of turbomachinery,and its accuracy is an important factor in determining whether the blade can meet the demand of design and processing.Based on the NURBS curve,the method of describing the meridional plane,mean camber line and thickness distribution of the centrifugal compressor and the radial turbine impeller is studied,this method solves the problem of coordinate transformation and blade stacking in the modeling process.A parametric modeling method for radial-flow impeller blades was developed and a corresponding computer program was developed to provide a geometric basis for the subsequent optimization design.An optimized platform for radial Turbomachinery was constructed by Integrating three module of parametric modeling,three-dimensional CFD calculation and numerical optimization,this platform use the Latin hypercube method for design of experiment,by constructing the second-order response surface approximation model and adaptive simulated annealing algorithm,the global optimal aerodynamic optimization design was achieved.And this paper applies this platform to specific radial impellers.Take the Krain impeller as baseline design.Based on the parametric modeling method to reduce the blade profile,the aerodynamic performance of the modeling impeller and the original impeller was compared,the results of three-dimensional numerical calculation verify the validity of the parametric modeling method.Taking the control points of the blade metal angle as the design variables,the aerodynamic optimization design was carried out.The performance and flow field generated through 3D numerical calculation of the optimized and baseline design was compared.The efficiency and pressure ratio of the optimized impeller were higher than those of the baseline throughout the entire working range.A radial flow turbine blade is modeled using the developed parametric modeling method.In order to further verify the effectiveness and versatility of the method,numerical analysis is carried out for the parametric and original geometry.Based on the parametric blade,the control point of the shroud and hub section profiles are set as the design variables during the aerodynamic optimization design.The three dimensional flow conditions between the parametric and original geometry is compared using 3D numerical calculation,results show that the efficiency and mass flow rate are both improved after optimization design.Through blade modeling and aerodynamic optimization,the aerodynamic performance of the centrifugal impeller and radial flow turbine are both improved,which verified the effectiveness and versatility of the developed parametric modeling method,as well as the proposed response surface optimization design system.