Research On The Design Of Hydrodynamic Retarder Based On CFD

This dissertation is supported by the national fund project of key laboratory of the vehicle transmission—Optimal Design of Efficient Hydrodynamic Retarder. Firstly in this paper, the background of the research and the application of the hydrodynamic retarder in the world had been introduced. Then this paper introduced the current problems of hydrodynamic retarder and the development trends in the future. The development of the design methods of hydrodynamic retarder was summarized. At present, the design of hydrodynamic retarder is based on the one-dimension flow theory, which can not study the internal flow and principle of hydrodynamic retarder. In this research, the internal flow field of the hydrodynamic retarder D375 was simulated by CFD software FLUENT.The theories of one-dimension flow and similitude principle were used for the characteristic calculation of three types hydrodynamic retarder with different blade angles 30°,40°,45°.The results of characteristic calculation were used for the reference conclusion.The geometric model was created by UG, based on some assumptions and predigestions. The grid was created by mapping method. Mixing plane model was used in mutual faces between impellers. The turbulent model was the standard k-εmodel. SIMPLE velocity-pressure coupling algorithm and the first order upwind scheme had been chosen for the calculation. Boundary conditions had been set up based on the one-dimension flow theory. Brake torque was monitored when the iterative calculation was in the process. When the convergence achieved, the size of brake torque was achieved.The results by fluent had been analyzed and compared with those of the one-dimension flow theory. Blade angle had been chosen by the comparison. Some improvements in the design of local parts of hydrodynamic retarder were made. Thickness of the blade was optimized. The strength check of blade had been executed according to the stress analysis and design method; In order to improve the efficiency of liquid-filled, the shape of pump blades was improved. In order to make the device which used for reducing the air blast loss more innovative, more reasonable and more reliable, the device was improved. The strength check of spline had been executed at last.The dissertation had done some research on the process of hydrodynamic retarder design and set up a preliminary hydrodynamic retarder design method of CFD-based, one-dimensional flow theory as a supplement. This research had made contributions to enhance the design level of hydrodynamic retarder.