A theoretical analysis of dynamic characteristics of finite hydrodynamic journal bearings lubricated with coupled stress fluids

Abstract

Based on the microcontinuum theory, a theoretical investigation into the rheological effects of coupled stress fluids on the dynamic characteristics of finite hydrodynamic journal bearings is presented. The modified Reynolds equation governing the film pressure is obtained by using the Stokes equation of motion which considers the coupled stress effects resulting from the lubricant blended with various additives. Using the first-order perturbation of the dynamic modified Reynolds equation, the dynamic characteristics in terms of the dynamic response coefficients, stability parameter and whirl ratios are obtained for various eccentricity ratios and coupled stress parameters. According to the results obtained, this theoretical investigation suggests that the influence of coupled stress effects on the dynamic performance of the system is physically apparent and not negligible. Overall, the coupled stress effects improve the dynamic characteristics of the journal bearing system.