This paper presents a numerical study about lubricant inertia effect on
thermohydrodynamic (THD) characteristics of Rayleigh step bearings running under steady,
incompressible and laminar condition. To reach this goal, the set of governing equations
is solved numerically with and without considering the inertia terms. The discretized
forms of the momentum and energy equations are obtained by the finite volume method and
solved using the Computational Fluid Dynamic (CFD) technique. These equations are solved
simultaneously because the dependency of lubricant viscosity with temperature. The
hydrodynamic and thermal behaviors of the slider step bearings are demonstrated by
presenting several figures including the lubricant pressure and temperature distributions
with and without considering the fluid inertia effect. Numerical results show that inertia
term has considerable effect on THD characteristics of step bearings, especially when they
run with high velocity of runner surface.