Abstract: The effect of fluid inertia is generally neglected in view of its negligible contribution compared to viscous force in the analysis of hydrodynamic journal bearings. The fluid inertia effect cannot be neglected when the viscous force are of the same order of magnitude and then the fluid inertia effect is to be taken in the analysis when the Modified Reynolds number is around one. Since no machining surfaces are perfectly smooth so the assumptions of smooth surfaces can no longer be employed to accurately predict the performance characteristics of journal bearing systems. This theoretical work analyses the combined influence of surface roughness and fluid-inertia effects on performance characteristics of hydrodynamic journal bearing. The average Reynolds equation that modified to include the fluid inertia and surface roughness effect andis used with appropriate boundary conditions to obtain pressure profile in the fluid-film region. The solutions of modified average Reynolds equations are obtained using finite difference method and appropriate iterative schemes. The effects of surface roughness parameter, roughness orientation, and roughness characteristics of opposing surfaces including fluid-inertia effectssimultaneously on circumferential fluid-film pressure distribution, load carrying capacity of the bearing are studied. The steady state bearing performance analysis is done through parametric study of the various variables like modified Reynolds number, eccentricity ratio, slenderness ratio, attitude angle, surface roughness parameter, surface pattern parameter. The variation of bearing load carrying capacity, attitude angle, end flow, friction parameters has been studied and plotted against various parameters.
Keywords: Modified Reynolds number, slenderness ratio, attitude angle, sommerfeld number, eccentricity ratio, journal bearings, fluid inertia, roughness pattern and roughness parameter.
Title: Steady State Performance Analysis of Finite Oil Journal Bearings considering Fluid Inertia and Surface Roughness effect
Author: A. K. Bandyopadhyay, S. K. Mazumder, M. C. Majumdar
International Journal of Mechanical and Industrial Technology
ISSN 2348-7593 (Online)
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