The Effect of a Translating High Aspect Ratio Particle in a Plane Slider Bearing

An approximate solution of Stokes equations is presented to determine the pressure and velocity fields in an infinite slider bearing containing a two-dimensional high aspect ratio particle of arbitrary cross-section. The particle may translate in two directions as well as rotate about its centroid. The fluid field is divided into four regions: upstream, above, below, and downstream of the particle. The governing Stokes equations are applied to each region and solved through specific continuity requirements and pressure matching conditions. For illustrative purposes, this method of analysis is applied to a plane slider bearing containing a rectangular particle which can translate in one direction. Approximate solutions are given for the pressure and velocity fields. The solution reveals a pressure drop which develops in the pressure field at the particle location. The magnitude of this drop is shown to be dependent on a particle size, velocity, and location. It is shown that the particle has a major effect on the bearing pressure field when it is able to significantly obstruct the flow of the lubricant. To support the theoretical analysis, experimental research is performed. An experimental apparatus is used to measure the transient pressure in a slider bearing as a high aspect ratio two-dimensional rectangular particle is passed through the fluid film. The apparatus measures pressure at a particular location in the bearing and simultaneously measures the particle’s displacement with respect to its initial starting location. Results are given to demonstrate the effect of particle velocity on the pressure field in the bearing. The experimental results presented are in good agreement with analytical results obtained from the theoretical analysis.