Simulation And Research Of A Hydrodynamic Retarder's Performance In Vehicle Based On 3-D Flow Calculation

The research is a part of national fund project of key laboratory of the vehicle transmission.The internal flow field of the hydrodynamic retarder D375 is simulated by UG and FLUENT etc,characteristic curve is obtained based on 3-D flow field theory.Test results and simulated results are compared.The research has been used the CFD technology to study the internal flow and principle of hydrodynamic retarder, and the purpose is to guide the design of hydrodynamic retarder and improve its performance,meanwhile,for the independent research and development.It has significant meaning to economic growth of our country.Firstly in this paper,the background of subject research and the application of the hydrodynamic retarder in the world have been introduced.The current situation of the development of the field flow theory has been listed.Some CFD software has been introduced and CFD software FLUENT has been chosen to carry on this research,then structure and operation principle of the hydrodynamic retarder have been explained and main contents of this research has been introduced.This paper has analyzed the basic theories of CFD in this research.Then introduced the discrete scheme,creation technology of the grid and turbulent model in detail,introduced the method of near wall treatment methods and the algorithm of calculating field flows.The geometric model is created by UG,based on some assumptions and predigestion.Grid is created by mapping method,in order to improve the precision of calculating,using the grid of hexahedron.The realizableκ-εmodel,SIMPLE velocity-pressure coupling algorithm,separated solver,the implicit scheme model and the standard wall function has been chosen,and boundary conditions have been set up, such as wall boundary condition and sliding meshes condition.When the convergence achieved,this paper has made deeply analysis with velocity field and pressure field under some operating condition.The results of calculation has been analyzed and compared with those of experiment and the beam fluid theory,which proved the validity of three-dimensional calculation. This research has achieved more and clearer understandings of the internal flow and principle of hydrodynamic retarder which can do some help for the independent research and development of retarder.A new design method of retarder based on CFD technology has been carved out which point out the orientation for the farther research.