Surface Roughness Effect on the Performance of 3-lobe Symmetric Hole Entry Hybrid Journal Bearings

Abstract

The present paper, evaluates the effect of surface roughness on the performance characteristics of capillary compensated 3-lobe symmetric hole entry hybrid journal bearing. The effect of surface roughness patterns viz; transverse, isotropic, longitudinal and smooth, on bearing performance is presented for different values of offset factor. A modified form of Reynold’s equation in conjunction with restrictor flow equation is solved by using Galerkin’s technique of FEM. The numerically simulated results of the study indicate that the surface roughness orientation patterns affect the performance of 3-lobe hybrid journal bearing system significantly. Further, it is noticed that the longitudinal roughness pattern provides enhanced value of rotor dynamic coefficient.To have an improved dynamic performance, a judicious selection of offset factor and surface roughness pattern parameter is essential.