Design And Optimization Of Hydrodynamic Torque Converter Blade Based On NASA Airfoil System

As an important hydrodynamic transmission component,hydrodynamic torque converter has excellent characteristics of automatic adaptability,continuously variable and isolation,which is widely used in automobile,construction machinery and other fields.Blade design is the most important link in the development of a hydrodynamic torque converter,while the traditional blade design method has the disadvantages of tedious design process and reliance on the experience of the designer.In this paper,the design and optimization of the hydrodynamic torque converter blade are studied.A design method of the hydrodynamic torque converter blade based on NASA airfoil system is proposed.This method is applied to redesign the impeller blades of the existing YB-290 hydrodynamic torque converter,and the new impeller blades are optimized.Compared with the prototype,the maximum efficiency of the modified YB-290 is improved.Analyzes the change law of the modified YB-290’s performance with the design parameters of the new blade,and explains it from the perspective of flow field analysis.The main research contents of this article are as follows.(1)A design method of hydrodynamic torque converter blade based on NASA airfoil system is proposed.By searching the NASA airfoil family tree,the airfoil equations suitable for the design of the hydrodynamic torque converter blades are selected,and the two-dimensional contours of the blades are constructed using the equations.The two-dimensional contours are projected inward and outward to generate a three-dimensional curve.The structured ruled surface generates blade solids,so that the shape of the blades can be parameterized.(2)CFD calculation of the existing YB-290 hydrodynamic torque converter.The three-dimensional model of the internal flow region of the YB-290 prototype hydrodynamic torque converter was extracted and the flow region was meshed.CFD calculation of YB-290 prototype with fluid analysis software,and the CFD calculation results were compared with the experimental data of YB-290,the errors between the two are within the allowable range,which verifies the accuracy of the CFD calculation and provides a theoretical basis for the optimization of blade parameters in the future.(3)The hydrodynamic torque converter blade design method based on the NASA airfoil system was used to modify the YB-290 impeller blades.The maximum efficiency and the width of the high-efficiency zone of the YB-290 were used as the optimization targets,and the modified impeller blades were optimized.Use the various design parameters of the blade as design variables,the design of experiments was used to generate uniform sample points in the design space,and accurate CFD calculations were performed on the sample points.The response surface method was used to construct a proxy model between the hydrodynamic torque converter performance and the blade design parameters.The proxy model was tested with test points,and all indicators reached the required standards.The AMGA multi-objective optimization algorithm was selected to optimize the blades.The response value of the optimal pareto solution was compared with the CFD calculation results.It was found that there was only a small deviation between the two,thereby verifying the reliability of the optimization results.The optimized maximum hydrodynamic torque converter efficiency was increased from 83.3% to 84.8%.(4)The influence of blade design parameters on the performance of hydrodynamic torque converter is studied.Through the analysis of the sample data calculated by CFD,the main influencing factors of each performance of the hydrodynamic torque converter and the main effects and interaction effects between the design parameters and each performance of the hydrodynamic torque converter are obtained,and the reason why the blade design parameters affect the performance of the hydrodynamic torque converter is revealed from the perspective of flow field analysis,it can provide a certain reference for the blade design of the hydrodynamic torque converter in the future.