Texture shape effects on hydrodynamic journal bearing performances using mass-conserving numerical approach

Abstract

lt is a known fact that incorporating textures in the contact surfaces can significantly enhance bearing performances. The purpose of this paper is to outline the effects of texture bottom profiles and contour geometries on the performances of hydrodynamic textured journal bearings. The analysis was conducted using computational approach to test eight texture shapes: rectangular, cylindrical, spherical, triangular (TR, Tl, T2, T3) and chevron. The steady state Reynolds equation for modelling the hydrodynamic behaviour of thin viscous film was solved using finite difference technique and mass conservation algorithm (JFO boundary conditions), taking into account the presence of textures on both full film and cavitation regions. The comparison with the benchmark data shows good consistency and an enhancement in bearing performances (load carrying capacity and friction). The results clearly show that the mechanisms of wedge effect and micro-step bearing for the full/partial texturing feature are the main crucial parameters, where the convergent wedge effect present in T2 triangular texture shape can significantly enhance the load-carrying capacity, while the divergent wedge action causes a net load loss. Considering the right arrangement of textures on the contact surface, their surface contours can have a significant impact on the performance of hydrodynamic journal bearings at high eccentricity ratios.

Computational investigation on the performance of hydrodynamic micro-textured journal bearing lubricated with micropolar fluid using mass-conserving numerical approach

“…These have also been reported by many researchers. 70,71,74,77,78,87 In comparison with the Newtonian case, the pressure and the load capacity are higher and the friction coefficient decreases with micropolar fluids. 17,18,19…”

“…The most common mechanisms were the “micro-wedge action”, 67 the “collective dimple effect”, 68 the “ inlet roughness”, 69 the “inlet suction mechanism”, 70,71 and the “balancing wedge action”. 72 Based on these mechanisms, several studies 73–77 have reported that textures with flat/wedge bottom profiles containing a micro-wedge and/or a micro-step bearing tend to increase film thicknesses and pressure lift. In a previous paper, 78 we have presented a comparative study concerning the combined influences of textured surface and journal misalignment on the performance of hydrodynamic journal bearing.…”

Implication of Surface Texture and Slip on Hydrodynamic Fluid Film Bearings: A Comprehensive Survey

“…Similarly, Tala-lghil & Fillon [91] and Wang et al [92] investigated the effect on overall temperature rise with different texture geometries on journal bearings. Wang et al [92], Manser et al [93], and Ramos et al [94] compared the static performance characteristics of textured journal bearing with smooth journal bearing surface. Similarly, Matele et al [95], Jiang et al [96], and Jhoon et al [97] compared dynamic performance characteristics of textured journal bearing with smooth journal bearing surface.…”

Proposal of texture shape optimization algorithm under constant load condition and considerations on new shape update equation (Texture shape optimization for minimization of friction coefficient)

“…The effect of texture on tribological properties also depends on the shape of the texture. This has prompted some research into texture shapes (Codrignani, 2018;Sharma, 2019;Manser, 2020). However, these studies mostly involve parameter studies and size optimization.…”