Effect of Dynamic Parameters on Squeeze-Swirling Flow Between Grooved Discs

Squeeze-swirling films are formed during the kiss-point filling phase of wet clutch engagement. These films play a critical role in enhancing torque transmission by enabling smooth engagement, reducing overshoots, improving cooling efficiency and minimising wear. Analytical studies have attempted to calculate the pressure and velocity distributions under these conditions, often relying on simplified assumptions based on the Reynolds equation. However, such assumptions are only valid under specific operating conditions and become inadequate when grooves are introduced into the system. To address these limitations, computational models have been used to solve the Reynolds equation, typically assuming a mixed lubrication regime at the beginning of the engagement, with film thicknesses below 30 µm. This study investigates the flow characteristics of squeeze-swirling films between grooved discs considering a hydrodynamic lubrication regime as the initial condition, using an initial film thickness of 150 µm. The Navier-Stokes equations are coupled with the dynamic force equilibrium equation to capture the transient nature of the process, instead of the quasi-static approaches commonly found in the literature. The results reveal significant differences in flow patterns between grooved and non-grooved regions, offering valuable insights into the filling phase and providing practical guidelines for improving the modelling and understanding of squeeze-swirling lubrication systems.