Study On Parameterized Cascade Design Of Radial-turbine Torque Converter

Since the blading of the torque converter transmits all of the torque, and the blades aretwisted, its design is of utmost importance. Herein a novel parameterized torque convertercascade design method based on Bezier curve was proposed. The method improved theflexibility and adaptability of torque converter cascade design system. In order to improvetorque converter design, the CFD technology, design of experiment and optimizationalgorithms were combined by automating and integrating geometry modeling, meshing and3D flow field simulating into a parameterized design system. The sensitivity analysis of thedesign parameters was performed to explore the relationship between design parametersand performances. The study enhanced torque converter performance and improved torqueconverter design approach.Based on the characteristic of torque converter blade, a Bezier-based parameterizedcascade design model was proposed. The control points were derived from the maingeometric control parameters such as camber line angle, crest and crest position, by whichblade interaction design was achieved.Aiming at the unfolding problem, the conformal transform was proposed to achievethe transformation between2D blade profile and3D blade curve. Compared with thetraditional multi-cylinder mapping method, the new approach eliminated the transformationerror, improved the blade design precision.Multi-level optimization procedure based on CFD was proposed to optimize cascadeparameters. Single flow passage model was firstly utilized to obtain fast optimization, andthen whole wheel transient simulation was performed to predict the performance preciselybased on the previous results and finally determine the optimum design parameters.The influence of design parameters on torque converter performance was analyzed andthe key design parameters were determined. The interaction relationship between designparameters and the relationship between design parameters and performances wasestablished and validated by experimental data.The optimization of a flat torque converter was performed based on the parameterizeddesign system and the optimized torque converter was manufactured and tested. A significant improvement in efficiency from75.7%to86.2%was found after optimization,hence the novel integrated design approach was validated.