FEM analysis for different configurations of non-recessed hole-entry hybrid journal bearings for non-Newtonian lubricants

Purpose - The present work aims to predict accurately the bearing design data for non-recessed hybrid journal bearings, considering the effect of non-Newtonian behavior of lubricant for different symmetric and non-symmetric bearing geometric configurations. Design/methodology/approach - The simultaneous solution of generalized Reynold's equation governing the laminar flow of incompressible lubricant and the equation of flow of lubricant through the capillary restrictor, considering variable viscosity of lubricant following the "Power law", has been carried out using FEM. For a given set of bearing geometric, operating parameters and for given external vertical load, the values of various performance characteristics have been obtained for a range of values of power law index, after establishing the journal center equilibrium position, the analysis for which has been elaborately explained. Findings - The results obtained have been presented graphically for various bearing performance characteristics. It has been observed that with decrease in power law index "n"(0 < n <= 1), the value of h(min)(-) and load carrying capacity decreases, while bearing flow rate increases for all configuration. The load-carrying capacity of asymmetric configurations is better and stable over entire range of restrictor design parameter. Bearing configuration with land width ratio = 0.25 and aspect ratio = 1.0, having two rows of holes and six holes in each row, will be better suited for high-load support, as it has maximum value of minimum fluid film thickness, moderate value of bearing flow and value of attitude angle is almost constant. Originality/value - The performance characteristics of journal bearing have been presented for a wide range of values of power law index and for different values of restrictor design parameter for capillary restrictor, after establishing the journal center equilibrium position. The comparison of the different symmetric and non-symmetric journal-bearing configurations to find the best geometric configuration at different operating conditions, considering the effect of non-Newtonian behavior of lubricant, represents the originality of the work.