The Performance Analysis Of Hydraulic Torque Converter Based On Fluid-structure Interaction And The Improved Design For Its Blade Construction

The hydraulic torque converter(HTC) is a kind of non-rigid torque converter which using liquid as the working medium to complete the torque transformation between the engine and the automatic transmission. Since it is a key component of the fluid drive vehicles, its performance will directly affect the performance of the vehicle. However, the HTC is multiple impellers fluid machinery, the surfaces of its blades and flow channels are both complex space surfaces, and there is mutual interference between the three impellers, its real internal flow is unsteady flow. Besides, in the actual working conditions, the stress situation of HTC blade is also complex. The blade is not only subjected the centrifugal force which is produced by rotation of impeller, its front and back are also subjected the pressure load which is produced by internal flowing. When the running speed of the HTC is too fast or the load increases too fast, the blades will be out of shape on the effect of the two forces those are mentioned above, then, the work efficiency will decrease.In order to improve the transmission efficiency of the vehicle, enhance the strength of blades and prolong the service life, the three-element HTC which contains core is taken as the research object. Its basic fluid mechanics calculation, accurate three-dimensional modeling, internal flow numerical simulation and performance analysis, leaf blade structure strength analysis and optimization construction of blade are researched in this paper. The main works are as follows:The working principle of the HTC is analyzed, and the characteristic parameters, the characteristic curves and the performance evaluation indexes are investigated. The accurate three-dimensional models of each part are built by UG, the three-dimensional models of each blades and they’re corresponding channels are obtained. A division mesh generating method is proposed, it can effectively solve the problem of the distortion of grid in the course of the finite element analysis, and the high quality mesh models are obtained.On the basis of proper hypothesis, the calculation formulae of three-dimensional flow is investigated. Aiming at the general process of fluid-structure interaction(FSI) analysis, the numerical method, turbulence model and velocity coupling algorithm are investigated. Then, on the three typical working conditions, the pressure and velocity distribution states of the pump wheel, turbine and guide wheel are analyzed by ANSYS/Fluent.The pressure load which is calculated by ANSYS/Fluent is imposed on the structural dynamical models of the blades, the deformation conditions and the equivalent pressure distributions of the blades those are produced by FSI are investigated. Based on the FSI analysis, the structural parameter optimization of the pump wheel blade is studied. The result of example verifies the rationality of parameter optimization.