Thermal and Inertia Effects in Hydrodynamic Lubrication of Rollers by a Power Law Fluid Considering Cavitation

Abstract

A theoretical aspect of hydrodynamic lubrication of two symmetric rollers by power law fluids is analyzed. The effect of fluid convective inertia, which is significant in case of high speed bearing, is taken into account. The effect of hydrodynamic pressure and temperature on the lubricant consistency m is assumed to vary with pressure and the mean temperature. The squeezing motion of the surfaces is also incorporated along with inertia and thermal effects. The Reynolds equation and the energy equation (with convection and conduction), which are coupled through m, are solved simultaneously. Various bearing characteristics such as pressure, temperature, load and drag etc. are obtained and a comparison between results (with and without inertia) is also made. It is noted that the effect of inertia is to increase pressure, temperature, load and drag etc. and to displace the position of pressure peak slightly towards the center line of contact of the rollers. An attempt is also made to study the variation of film thickness with load, speed, Eckert number, pressure, and temperature viscosity exponents.