Transient thermohydrodynamic of turbocharger thrust bearings with circumferential V-grooves

The primary objective of this paper is to numerically analyze the effect of circumferential V-grooves on the thermohydrodynamic performance of turbocharger thrust bearings, with a focus on lubricant temperature distribution and variation. To investigate the relationship between shaft speed and lubricant temperature, a thermohydrodynamic lubrication model was employed to obtain numerical results. The numerical methodology utilizes the finite difference method coupled with the Newton-Raphson scheme to solve the nonlinear modified Reynolds and energy equations concurrently. To ensure accuracy, steady-state numerical predictions of pressure and temperature distributions were validated against existing research. Subsequently, the numerical findings, focusing on oil pressure, friction, and oil temperature under varying shaft speeds, are thoroughly discussed. The numerical findings indicate that the implementation of grooved thrust bearings with a 5 mm clearance reduces the average lubricant temperature in the contact area by 14% at maximum operating speeds, while maintaining friction levels comparable to those of ungrooved counterparts. However, an excessive increase in groove width and depth adversely affects the bearing's load-carrying capacity and results in higher peak temperatures at the bearing plate edge, especially at widths and depths greater than 30 mm.