Computational Fluid Dynamics Thermohydrodynamic Analysis of Three-Dimensional Sector-Pad Thrust Bearings With Rectangular Dimples

Abstract

The paper presents a detailed computational study of flow patterns and performance indices in a dimpled parallel thrust bearing. The bearing consists of eight pads; the stator surface of each pad is partially textured with rectangular dimples, aiming at maximizing the load carrying capacity. The bearing tribological performance is characterized by means of computational fluid dynamics (CFD) simulations, based on the numerical solution of the Navier–Stokes and energy equations for incompressible flow. Realistic boundary conditions are implemented. The effects of operating conditions and texture design are studied for the case of isothermal flow. First, for a reference texture pattern, the effects of varying operating conditions, in particular minimum film thickness (thrust load), rotational speed and feeding oil pressure are investigated. Next, the effects of varying texture geometry characteristics, in particular texture zone circumferential/radial extent, dimple depth, and texture density on the bearing performance indices (load carrying capacity, friction torque, and friction coefficient) are studied, for a representative operating point. For the reference texture design, the effects of varying operating conditions are further investigated, by also taking into account thermal effects. In particular, adiabatic conditions and conjugate heat transfer at the bearing pad are considered. The results of the present study indicate that parallel thrust bearings textured by proper rectangular dimples are characterized by substantial load carrying capacity levels. Thermal effects may significantly reduce load capacity, especially in the range of high speeds and high loads. Based on the present results, favorable texture designs can be assessed.

Numerical Study of the Influence of Geometric Features of Dimple Texture on Hydrodynamic Pressure Generation

“…When H min is 30 µm, the maximum pressure difference for the non-textured and textured cases is less than 3%. Papadopoulos et al [9] analyzed the dimples effect on thrust bearing using CFD, the results indicates the optimized dimple depth close to the minimum film thickness. As shown in Figure 9, for all four lines, the highest pressure is shown when the dimple depth is 10 µm.…”

“…The results suggested the dimple bottom shape affected the film thickness. Papadopoulos et al [9] performed simulations using commercial CFD software and found a higher load capacity when a squared dimple surface was applied. Zhang et al [10] performed three-dimensional CFD simulations for water-lubricated step thrust bearings with different bearing dimensions, film thicknesses, and step heights and positions.…”

Influence of surface texturing on the hydrodynamic performance of a thrust bearing operating in steady-state and transient lubrication regime

“…The increase of the load-carrying capacity of thrust bearings would allow a reduction of their dimensions, which would be consistent with the current technological trends that require a downsizing of mechanical components. Therefore, the optimization of thrust bearings through surface texturing has been the subject of an increasing number of both theoretical and experimental works [2][3][4][5][6][7][8][9][10].…”

Study of coating's effects on mechanical performances for sleeve of cotton picker with fluid–structure interaction method

“…The conventional Reynolds equation, however, will largely underestimate lubrication performances for tribological pairs with big Reynolds number of the lubricant or small bearing clearance. 9,10 Correspondingly, computational fluid dynamics (CFD) method and further fluid-structure interaction (FSI) method have been recently adopted for analyzing lubricated components by a few researchers only. For the CFD method, the general Navier-Stokes equation is solved without any simplification.…”