Design Issues for Variable Speed Torque Converters
The design of torque converters and particularly of variable speed turbo couplings offers designers some unique and challenging problems, especially from a hydrodynamic point of view. The closed-loop circuit inside which the fluid evolves is composed of two or more components which must operate and interact efficiently. The variable design conditions, under which the torque converter has to operate, further complicate its hydrodynamic optimisation. Several design loops are usually necessary to optimise and “synchronise” the different components.
With this in mind, the Voith Turbo design team decided to introduce TURBOdesign1 into their design process in order to maximise the hydrodynamic performance of their torque converters and to speed up their design process.
Excellent results have been achieved in little time, as confirmed by the experimental campaign conducted on one of the original designs and on the new designs achieved using TURBOdesign1 in combination with CFD.
Large efficiency improvements up to 10 points have been obtained by the optimisation of the hydrodynamic guide vane design over a wide range of speed ratios as shown in the data above.
By applying TURBOdesign1 to torque converters it has been possible to achieve the best matching between components, control secondary flows and suppress flow separation.
The introduction of TURBOdesign1 into Voith Turbo’s design process, enabled us to achieve significant improvements in the hydrodynamic performance of our blade designs, within very short time. The use of TURBOdesign1 also enabled us to handle conflicting requirements in a straight-forward way.