Effect of Turbulence on Stability of Journal Bearing with Micropolar Lubrication: Linear and Non-linear Analysis

Abstract

The object of the present article is to theoretically study the effect of turbulence on the stability of finite hydrodynamic journal bearing lubricated with micropolar fluid. Both linear and non-linear stability analyses have been carried out. In linear stability analysis, first-order perturbation method has been applied to obtain the steady-state and dynamic pressure equations. These equations have been solved to obtain the steady-state and dynamic pressures. These pressures were used to compute the dynamic film forces along with the stiffness and damping coefficients. These force components and dynamic response coefficients have been used to obtain the critical mass parameter and whirl ratio. In non-linear analysis, the transient Reynolds equation was solved using successive over relaxation scheme to obtain dynamic pressure field which in turn used to obtain the film forces and steady-state load capacity. The equations of motion have been solved using fourth-order Runge–Kutta method to obtain the threshold of stability. It is observed that the stability of the journal bearing system decreases with increase in turbulence.