Thermohydrodynamic analysis of a textured sector-pad thrust bearing: effects on mechanical deformations

Abstract

-In this paper, a computational investigation of thermohydrodynamic performance and mechanical deformations of a fixed-geometry thrust bearing with artificial surface texturing is presented. A parallel eight-pad bearing is considered; the surface of each pad is partially textured with square dimples. Here, a CFD-based thermohydrodynamic modeling approach, recently introduced by the authors, is used to calculate the performance of the bearing; the THD results are then used to quantify the deformations of the bearing mechanical parts. The bearing is modelled as a sector-shaped channel, consisting of a smooth rotating wall (thrust collar) and a partially textured stationary wall (bearing pad). The bearing performance characteristics are computed by means of numerical simulations, based on the numerical solution of the Navier-Stokes and energy equations for incompressible flow, as well as on the solution of the elasticity equations for the bearing solid parts. Here, a reference texture geometry is considered, while proper thermal and structural boundary conditions are implemented. For representative film thickness values, the effect of rotational speed and collar thickness on bearing performance is quantified, and the resulting pad and rotor deformation fields are computed. It is found that, due to oil heating, the load carrying capacity decreases with rotational speed for values higher that approximately 2000 rpm. The computed rotor deformation field is representative of a fixed support beam, characterized by substantially higher levels than those of the bearing pad. Rotor deformations increase substantially at low values of collar thickness.

Numerical micro-texture optimization for lubricated contacts—A critical discussion

“…However, texturing both surfaces resulted in additional improvement. Based on CFD approaches by solving the Navier-Stokes equations as well as the energy equation in the fluid and heat transfer equation in the pads, Papadopoulos et al [40][41][42][43] showed a considerable increase of the load-carrying capacity only for lower to moderate sliding velocities, while the improvement was reduced for higher velocities. However, the partially textured linear plain bearing exhibited lower friction due to the lower lubricant film height.…”

Effects of the dimple geometry on the isothermal performance of a hydrodynamic textured tilting-pad thrust bearing

“…In 2011, Papadopoulos et al [13] presented an optimization study where they used a CFD code to solve the Navies-stokes and energy equations; the authors neglected the effects due to the cavitation. The optimization goal is the maximization of the bearing load carrying capacity.…”

Performance of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and couple stress lubricant

“…The presence of certain textured features is known to may benefit some lubricant systems by acting as microreservoirs, storing and providing the fluid directly to the contact zone. The use of a textured bearing system has been found to be more demanding due to its advantageous features such as low value of friction, higher load carrying capacity, decreasing surface damages and increasing service life of bearing [11,12]. In the recent year, many bearing designers focused on the influence of surface texture in the fluid film journal bearing system.…”