Study On Performance Improvement Of Dual-Turbine Hydrodynamic Torque Converter

As one of the core components of hydraulic transmission system,dual-turbine hydrodynamic torque converter is widely used in the construction machinery industry and improving the efficiency of the torque converter is the key.According to the scientific research project entrusted by "Zhejiang Linhai Machinery Co.,LTD.",the internal flow field and the performance of dual-turbine hydrodynamic torque converter is calculated and analyzed by using computational fluid dynamic(CFD).According to Optimization modification of variety the scheme of the pump,the first turbine and the second turbine and detailed analysis of retrofit results,an optimization scheme is obtained.The torque ratio and efficiency of dual-turbine hydrodynamic torque converter is improved.The main research contents are as follows:1.According to the manufacturer's hydrodynamic torque converter woodenpatterns data,geometric mode is builded by SolidWorks modeling software,and the calculated flow model geometric model is imported into Bladegen.The use of CFX software for numerical simulation and according to the results of numerical simulation,the internal flow of each speed ratio of the pump,the first turbine,the second turbine and the stator is analysed and the original characteristics of dual-turbine hydrodynamic torque converter is predicted.The correctness of this method is verified by comparing with the test results;2.For the situation of the first turbine inlet and outlet,a best optimization scheme is obtained by changing the blade thickness,number and inlet blade angle of the first turbineand numerical simulation of various retrofit scheme.The starting torque ratio is increased from 3.9 to 4.12 and the efficiency of he condition under the speed ratio(0.3~0.703)is increased by 2% ~5%.3.According to the situation of the second turbine inlet and outlet,a best optimization scheme is obtained by adjusting the inlet blade angle of the second turbine and numerical simulation of various retrofit scheme.The efficiency of the condition under the speed ratio(0.3~0.673)is increased by 1% ~ 2%.4.According to the optimal combination of scheme of the first turbine and the second turbine and numerical simulation of the combination scheme,the starting torque ratio is increased from 3.9 to 4.16 and the efficiency of he condition under the speed ratio(0.3~0.703)is increased by 3% ~6%.Through the modification of the outlet of the pump,The flow characteristics such as jet / wake,circumfluence and vortex are improved.According to the result of numerical simulation,the starting torque ratio is increased from 3.9 to 4.28 and the efficiency of he condition under the speed ratio(0.3~0.646)is increased by 4% ~6.5%.