A CFD Analysis of Viscous Coupling Groove Efficiency for Thermal Management

Viscous couplings are pivotal in automotive drivetrains for proper torque transfer, prized for their simplicity and smoothness. Their significant drawback, however, is the heat generated from viscous dissipation, which can lead to fluid breakdown and mechanical failure. Existing research has documented how surface grooving boosts torque transmission, but the fluid flow and thermal effects remain poorly understood. This study conducts a coupled thermo-fluid dynamic analysis to evaluate how simple radial grooves impact torque capacity by shifting the transfer mechanism from viscous shearing to fluid momentum, thereby enabling better thermal management. A computational fluid dynamics (CFD) model of a disc was developed, with an inner radius of ۱۰ mm, an outer radius of ۳۰ mm, and an oil film thickness of ۰.۱ mm. The results confirm that a groove (۰.۱ mm width, ۰.۰۵ mm depth) augments transmitted torque by approximately ۵ times more --- from ۰.۰۷۵ Nm to ۰.۳۷ Nm --- at ۳۰۰ rad/s, consistent with existing research. Interestingly, the thermal analysis reveals that the grooved configuration operates at just slightly higher temperature (۱۲۵°C vs. ۱۱۶°C for a smooth disc after ۱ second). This shows that simple grooving (from a manufacturing point of view compared to bladed pump and turbine systems) promotes torque to be transferred via fluid momentum rather than viscous shearing which does not cause the unwanted swirling that generates excessive frictional losses.

کلیدواژه ها:

Viscous Coupling ، Thermal Analysis ، Computational Fluid Dynamics ، Groove Optimization ، Automotive Drivetrains ، Heat Dissipation