PERSPECTIVE - FLUID-DYNAMICS AND PERFORMANCE OF AUTOMOTIVE TORQUE CONVERTERS - AN ASSESSMENT

Experimental investigations by various groups over the past decade hav e uncovered the main features of the flow hydraulic torque converters. Measurement techniques include laser and hot wire velocimetry, fast r esponse and conventional five-hole probes, and blade and wall static p ressure measurement. In both the pump and turbine, the through flow ve locity is high near the pressure surface shell corner while the flow i n the suction surface core corner is highly turbulent and may be separ ated and reversed. The position of the stator in a passage curved in t he meridional plane leads to secondary flow and low velocities at the core near the pump inlet. Velocity gradients coupled with flow turning and rotor rotation lead to strong secondary flows. By using data from a combination of measurement techniques, torque converter torque, pow er and efficiency are calculated, and the effect of element efficiency on overall efficiency is demonstrated. It is concluded that design me thods should be developed that allow for nonuniform velocity profiles, flow separation, secondary circulation and interaction effects betwee n elements.