Abstract:

Because of the lack of accuracy and flexibility, the traditional blade modelling method is not suitable for torque converter 3D flow design. The novel 3D blade modelling approach based on Bezier curves and conformal transformation is proposed to solve the problem. The 2D blade profile is constructed by adding a thickness distribution to the camber line, and both the camber line and thickness distribution composed of two cubic Bezier curves. The control points are derived from the main geometric control parameters, by which geometric blade design is achieved. The conformal transformation is carried out to transform between 2D blade profile and 3D blade curve, which improves the design accuracy. The 3D blade entity is constructed by stacking 3D curves. The second derivative and curvature of the blade curve generated by the novel method are continuous, thus the hydrodynamic performance is improved, and the novel blade design method improves the accuracy and flexibility. An optimum pump blade is generated based on the new method and then tested. The hydrodynamic performance of the optimized torque converter is improved and thus the novel Bezier blade modeling method is validated.

Key words: Bezier curve, blade modelling, conformal transformation, torque converter, fluid transmission and control