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This article examines the effect of couple stress lubricant on the characteristics of six-pocket hybrid irregular journal bearing system. Various shapes of irregular journals viz. barrel, bell-mouth, and undulated journal are considered in the analysis. To model the behavior of the flow of couple stress lubricant in bearing clearance space, the modified form of Reynolds equation is derived by using Stokes theory. The unknown pressure field in Reynolds equation is determined by using Galerkin's method. To illustrate the effect of couple stress lubricant on bearing system, the results for characteristics parameters of journal bearing system are presented. The results noticeably reveal that the presence of different geometrical irregularities in journal may ominously influence the performance of bearing system. Further, the use of couple stress lubricant instead of Newtonian lubricant offers a significant improvement in the value of bearing characteristic parameters of geometrically irregular hybrid journal bearing system viz. ... [ABSTRACT FROM AUTHOR]

In the present work, an investigation has been performed on a rigid rotor supported by two-lobe journal bearings operating with a non-Newtonian lubricant. The governing Reynolds equation for pressure field is solved by using non-linear finite element method. Further to study the dynamic stability of the bearing system, governing equation of motion for the rotor position is solved by fourth order Runge–Kutta method. Bifurcation and Poincaré maps of two-lobe bearings are presented for different values of the non-Newtonian parameter and bearing ellipticity ratio. The numerical results illustrate that the ellipticity of a bearing with a dilatant lubricant improve the stability of the rotordynamic system. [ABSTRACT FROM AUTHOR]

The present paper deals with the theoretical study of geometric imperfections of journal and its influence on the performance of capillary-compensated six-pocket hybrid journal bearing configurations with different geometric shapes of recess. The analysis includes the geometric imperfections of journal such as barrel shape, bellmouth shape, and circumferential undulations and various geometric shapes of recess (square, circular, elliptical, triangular) of same pocket area. The governing Reynolds equation is solved using Galerkin’s technique. The numerically simulated results indicate that the selection of suitable geometric shape of recess is important to have the least influence of different geometric imperfections of journal on the bearing performance. [ABSTRACT FROM PUBLISHER]