Study of Stiffness and Damping Coefficients Developed in a Hydrodynamic Journal Bearing with Thin Porous Bush under Micropolar Lubrication

Abstract

The stiffness and damping parameters in a hydrodynamic journal bearing with a thin porous bush has been analyzed theoretically to study the beneficial effect of micropolar lubricant over Newtonian one. The Laplace equation in porous matrix is derived using the Darcy’s equation and a general Reynolds equation is developed in bearing clearance zone for porous hydrodynamic journal bearing using micropolar fluid. The perturbation method is employed to find the dynamic response of Laplace and Reynolds equation. Modified Laplace and the general Reynolds are solved by finite difference technique with successive over relaxation scheme to account the steady-state and the dynamic film pressure in porous bush and the bearing clearance zone. The numerically computed results of stiffness and damping parameters of porous hydrodynamic journal under micropolar lubricant corresponding to varying bearing feeding parameter are presented for both Newtonian and micopolar lubricants.

Keywords: Hydrodynamic lubrication, porous bush, micropolar fluid, stiffness and damping coefficients