PhD. Transactions of Machine Elements Division. Lund 1982

Abstract:

Analysis of hydrodynamic torque converter is the subject of this report.The flow is assumed to be two-dimensional, that is no variation in the circumferential direction, frictionless, and stationary. Infinitely thin blades and constant fluid density are also assumed. Governing equations and applicable numerical techniques are examined and numerical results are obtained for the three-element torque converter W240 (Fichtel & Sachs). The torques thus obtained appeared to be only slightly greater, at most 10% for the pump and 6% for the turbine, than the torques obtained from the frequently used one-dimensinal theory.

Some experiments were carried out with the actual torque converter. Measured and calculated turbine torques were compared and it was found that the two-dimensinal theory produce satisfactory values, a little better than the one-dimensional one. A friction factor which accounts for the dissipation of real flow was also evaluated. An exploration of other modes of operation, including backwards rotation of pump and turbine, showed that satisfactory prediction of these is possible in some cases.

The final conclusion is that the commonly used one-dimensional theory is useful when analysing the performance of a torque converter, whilst the two-dimensional theory is relevant when the flow pattern in it is subject of interest.