Theoretical analysis of an infinitely wide rigid cylinder rotating over a grooved surface in hydrodynamic conditions

Abstract

A theoretical model that evaluates the frictional properties of an infinitely wide rigid cylinder rotating over a grooved surface in a hydrodynamic lubrication regime is presented in this article. The parabolic approximation of the film thickness is used in order to analytically compute the pressure distribution in the fluid film. At the discontinuities of the grooved surface, the conservation of the flowrate is applied. The pressure distribution was also computed using a commercial CFD software. Different groove depths are tested using the two methods in order to establish whether the Reynolds equation is valid for low dimple aspect ratios. It is found that the Reynolds equation is not valid when the depth of the groove is comparable with its width. In the case where the width of the grooves is much larger than their depth, the obtained results (CFD and analytical) are perfectly similar. The load-carrying capacity and the friction force of the couple are also computed.

Research on the influence of micropits structure on the tribological performance of friction pairs

“…10 Marian et al. 11 established a theoretical model of the textured surface of an infinitely wide rigid shaft, and introduced the boundary conditions of Jakobsson–Floberg–Olsson (JFO), and then analyzed the influence rules of the texture surface on the rigid rotation axis. Yu 12 established a numerical model for cylindrical dimples, showed that the depth-to-diameter ratio and area ratio of micro-dimples were the important factors that affected the surface lubrication properties of textured surfaces.…”

“…[5][6][7] The main mechanism of the effect of surface microdimple structure on the friction performance of the friction pairs is shown with regard to three aspects: under the condition of fluid lubrication, the microdimple structure can effectively produce hydrodynamic lubrication effects; under the condition of mixed friction, micro-dimples can be used as microoil tanks to make lubrication more effective; the worn abrasive particles can be stored effectively, and the occurrence of second wear can be reduced under the condition of boundary lubrication and dry friction. 8,9 With regard to the theoretical simulation calculation, the influences of different texture shapes including rectangles, circles, triangles on the working performance of journal bearing were researched based on the Reynolds equation by Rahmani et al 10 Marian et al 11 established a theoretical model of the textured surface of an infinitely wide rigid shaft, and introduced the boundary conditions of Jakobsson-Floberg-Olsson (JFO), and then analyzed the influence rules of the texture surface on the rigid rotation axis. Yu 12 established a numerical model for cylindrical dimples, showed that the depth-todiameter ratio and area ratio of micro-dimples were the important factors that affected the surface lubrication properties of textured surfaces.…”

Dynamic analysis of the rotor supported by journal bearing with micro-spherical surface texturing

“…The theoretical results were also confirmed by the experimental study of the authors. Jang and Marian et al 12,13 carried out theoretical analysis of journal bearing with a grooved surface, and they found that the parameters of the texturing have significant influences on the stability, load capacity, and tribological characteristics of journal bearing. Sinanog˘lu et al 14 investigated the effects of surface texturing on the load capacity, and the research showed that the trapezoidal texture is better than that of saw.…”

Experimental study of the effect of surface groove micro‐texturing on lubrication characteristics

“…The research on surface textures can be divided into theoretical and experimental approaches. With the theoretical approach, numerous studies have utilised the Reynolds equation or the Navier-Stokes equations to analyse the mechanism behind textured surfaces [4][5][6][7]. For example, Bai et al [8] numerically investigated partial texturing with elliptical dimples, and the results showed that the orientation of dimples can greatly enhance the hydrodynamic effect.…”

“…The research on surface textures can be divided into theoretical and experimental approaches. With the theoretical approach, numerous studies have utilised the Reynolds equation or the Navier–Stokes equations to analyse the mechanism behind textured surfaces [4–7]. For example, Bai et al .…”