Optimization Modeling And The Study Of Pump Flow Field Of Torque Converter

Hydrodynamic torque converter takes liquid as its working medium and it is a device that power is transmitted through interaction between the liquid and the wheel.The superior performance makes the Hydrodynamic torque converter widely used in various fields.However,its main disadvantage is that the efficiency is not high enough.It is very necessary to optimize the parameters,study and analyze the law of its inner flow field,so as to improve the performance and efficiency further.The main contents of this thesis are as follows:(1)A new theoretical method,meridional driving force equilibrium method,is proposed.The import side polar angle formulas of pump impeller are derived and then the formula of Hydrodynamic torque converter wheel's inlet and outlet edge radius are determined.(2)Based on the research of the parameters,the optimization of parameter is attributed to the optimization of meridional speedmv,then the optimization model of Hydrodynamic torque converter is established.Driving force was calculated and driving pressure was obtained.Put forward the way to modify the meridional speed through the analysis of pressure difference.(3)To build the pump duct model by adopting automated modeling technology.Duct model is considered as the rotation entity which is cut by two surfaces.With the help of software like program code,Auto CAD and UG,the pump duct model is automatically generated.(4)The Gambit software is used to mesh the pump duct model and then the grids are inputted to the software Fluent to be simulated numerically.SIMPLE algorithm and the stand k-? of turbulence model are selected in solving flow field computation.After setting all parameters,iterative computation is performed.(5)To analyze the velocity fields and pressure fields of hydrodynamic torque converter's pump according to the caculation data.Therefore we can get the high speed flow domains,low speed flow domains,high pressure domains,low pressure domains and reverse domains.(6)To export the calculation data of axial velocity,radial velocity,tangential velocity and pressure in the pump field of FLUENT.The program code was developed.,then the functional relation is simulated after finishing data fitting by using least squares method in MATLAB.Converted coordinate in the generalized coordinate system,then get the fitting function about ?????,finally the law of internal pressure and velocity of the pump was obtained.