Thermal Analysis of Lubricating Oil Flow Within a Wet-Disk Clutch

A combined theoretical and experimental thermal analysis is conducted on the oil flow between the plates of a wet clutch during an extended slip engagement. An analytical model, using the separation of variables technique, is developed to simulate the temperature rise due to the non-conservative friction and relative motion between the steel plates and friction plates of the clutch. A three-dimensional numerical heat transfer and fluid flow model was developed to calculate the velocity and temperature profiles in the oil groove channel. Typical velocity profiles and temperature contours plots are demonstrated. Friction factor and Nusselt number are presented as functions of axial position. The experiment performed included a wet clutch instrumented with thermocouples and installed in a power-shift transmission where the temperature rise during one clutch engagement was measured. The total energy is then estimated by accounting for system inertia, torque and rotating speeds. Finally, the inlet, outlet temperature rises and the averaged Nusselt number of the oil groove are also presented.