Nonlinear transient stability study of two lobe symmetric hole entry worn hybrid journal bearing operating with non-Newtonian lubricant

•Stability of a two lobe hole entry worn hybrid journal bearing.•Influence of non-Newtonian lubricant on bearing stability.•Trajectories of journal center motion have been obtained by using Runge–Kutta method.•Stability point of view, worn bearing surface may have positive effect.

The present paper, deals with a theoretical study concerning the effect of non-Newtonian lubricant on the stability of a two lobe symmetric hole entry worn hybrid journal bearing, compensated with constant flow valve restrictor. Trajectories of journal center motion have been obtained by solving the nonlinear equation of motion for the journal center with the Runge–Kutta method. The numerically simulated results indicate that the non-Newtonian behavior of the lubricant has a profound influence on the journal trajectories and stability of a worn hybrid journal bearing. A proper selection of parameters such as offset factor, wear depth parameter and the non-linearity factor may provide better bearing stability.