Application of topological optimisation methodology to finitely wide slider bearings operating under incompressible flow

Abstract

The search for the optimal bearing geometry has been on for over a century. In a publication from 1918, Lord Rayleigh revealed the infinitely wide bearing geometry that maximises the load carrying capacity under incompressible flow, i.e. the Rayleigh step bearing. Four decades ago, Rohde, who continued on the same path, revealed the finitely wide bearing geometry that maximises the load carrying capacity, referred to as the Rayleigh-pocket bearing. Since then, the numerical results have been perfected with highly refined meshes, all converging to the same Rayleigh-pocket bearing. During recent years new methods for performing topology optimisations have been developed and one of those is the method of moving asymptotes, frequently used in the area of structural mechanics. In this work, the method of moving asymptotes is employed to find optimal bearing geometries under incompressible flow, for three different objectives. Among the results obtained are (i) show new bearing geometries that maximise the load carrying capacity, which performs better than the ones available, (ii) new bearing geometries minimising the coefficient of friction and (iii) new bearing geometries minimising the friction force for a given load carrying capacity are presented as well.

Application of topological optimisation methodology to hydrodynamic thrust bearings

“…7 However, when the mesh was refined, shark-fin like features appeared in the transition zone between the pocket’s trailing edge and the flat land, similar to the ones found by the authors in the present work in Ref. 15 The shark fins were also found to contribute to an increased LCC. The geometries minimising the COF were also of pocket type, but without shark fins at the back end of the pocket.…”

“…A mesh convergence study was conducted for the LCC and the COT objectives, even though the methodology has already in Refs. 13,15 been proven to give convergence. The bearing geometries maximising the LCC obtained when using coarser meshes, were observed to closely resemble the pocket bearing that was found in Ref.…”

“…The main difference between the two differently refined geometries are the trailing edge of the pockets, here a finer mesh results in shark fins appearing. These shark fins have been previously addressed by Kalliorinne and Almqvist, 15 and they direct the fluid towards the centre line of the pocket, resulting in a slight increase in pressure build up. What is different here is that the size of the shark fins are different depending on which side of the pocket's middle line they are located, having larger shark fins with a larger radius.…”

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

“…The methodology was verified through comparison with the Rayleigh step-bearing [341] and successors [342][343][344][345][346][347][348][349][350]. One important result they found, was that increasing the mesh resolution unravelled features contributes to the increased load-carrying capacity and decreased friction [339,340]. Other results of interest are the outstanding performance and topographies of the optimised thrust bearings and washers (Fig.…”

“…In the series of papers, Kalliorinne et al [338][339][340] adapted and applied the globally convergent method of moving asymptotes (GC-MMA) optimisation methodology to optimise the geometry of HL bearings. They used the film thickness as control variable and considered the load-carrying capacity, the coefficient of friction, and the frictional torque as the optimised | https://mc03.manuscriptcentral.com/friction targets.…”