Showing papers by "Satish C. Sharma published in 2020"

A Study of Hole-Entry Grooved Surface Hybrid Spherical Journal Bearing Operating With Electrorheological Lubricant

Abstract: The performances of the tribo-pairs are greatly influenced by introducing the grooved surfaces. Developments of the newer type of lubricants have made a great impact on the performance of fluid film bearings. This article investigates the non-Newtonian behavior of electrorheological lubricant on the performance of grooved hybrid spherical journal bearing. The effect of different arrangements of grooves, i.e., partially grooved or fully grooved on the bearing surface, has been studied. The finite element method is used to numerically simulate the results. Furthermore, a parametric study is performed for optimizing the groove attributes. The present work demonstrates that the different grooved arrangements have a substantial influence on the bearing performance. It is revealed that the provision of grooves on the bearing surface decreases frictional losses and enhances the stiffness coefficients of the bearing. Furthermore, numerically simulated results indicate that the electrorheological lubricant enhances the value of minimum fluid film thickness and the stiffness coefficients (S¯xxandS¯yy) of spherical hybrid journal bearing. Improved bearing performance can be achieved by using the optimized grooved attributes together with the electrorheological lubricant.

Magnetohydrodynamics of Lubricant in Recessed Conical Hybrid Journal Bearing With Taper Error

Abstract: To improve the performance accuracy of a conical journal bearing system, the surface error needs to be considered in the analysis since a tiny difference in dimensional values can alter the performance; the consideration of surface error may degrade the performance behaviour of bearing. However, a better way to overcome such degradation may be to make use of magneto-hydrodynamics of fluid. Therefore, the present work is planned to investigate the impact of taper error and magneto-hydrodynamic (MHD) lubricant in recessed conical hybrid journal bearing. In present paper, the Reynolds equation is derived under stated assumptions along with frictional power loss expression and finally solved using Finite Element Analysis, Newton-Raphson method and Generalized Minimum RESidual method. The conducted research helped in determination of optimum values of recess width, land-width ratio and restrictor design parameter; and also obtaining the results corresponding to distinct performance indices. The outcome of these results may inspire practising designers for development of better tribo-components.

Rotor-dynamic performance of porous hydrostatic thrust bearing operating under magnetic field

Abstract: Purpose The porous bearings are commonly used in slider thrust bearings owing to their self-lubricating properties and cost effectiveness as compared to conventional hydrodynamic bearings. The purpose of this paper is to numerically investigate usefulness of porous layer in hydrostatic thrust bearing operating with magnetic fluid. The effect of magnetic field and permeability has been analysed on steady-state (film pressure, film reaction and lubricant flow rate) and rotor-dynamic (stiffness and damping) parameters of bearing. Design/methodology/approach Finite element approach is used to obtain numerical solution of flow governing equations (Magneto-hydrodynamics Reynolds equation, Darcy law and capillary equation) for computing abovementioned performance indices. Finite element method formulation converts elliptical Reynolds equation into set of algebraic equation that are solved using Gauss–Seidel method. Findings It has been reported that porosity has limited but adverse effects on performance parameters of bearing. The adverse effects of porosity can be minimized by using a circular pocket for achieving better steady-state response and an annular/elliptical pocket, for having better rotor-dynamic response. The use of magnetic fluid is found to be substantially enhancing the fluid film reaction (53%) and damping parameters (55%). Practical implications The present work recommends use of circular pocket for achieving better steady-state performance indices. However, annular and elliptical pockets should be preferred, when design criteria for the bearing are better rotor-dynamic performance. Originality/value This study deals with influence of magnetic fluid, porosity and pocket shape on rotor-dynamic performance of externally pressurized thrust bearing. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0289/

Finite element analysis of multirecess hybrid spherical journal bearing system

Abstract: The present work deals with finite element method analysis of a multirecess hybrid spherical journal bearing system. The governing equations have been discretized using Galerkin’s technique and are...

Influence of bearing surface irregularities on hybrid slot-entry journal bearing with electrically conducting lubricant:

Abstract: This study concerns with the numerical simulation of a hybrid slot entry journal bearing lubricated with electrically conducting lubricant under the influence of magnetic field for both thermal and...