Performance of Hydrodynamic Journal Bearing Under Influence of Solid Contaminants

Journal bearings are crucial in marine applications, such as ship propulsion systems and underwater turbines, where they reduce friction and support loads. However, the infiltration of solid contaminants, such as sand particles, can increase friction and wear, compromising bearing integrity. Despite extensive research on journal bearings, the impact of high concentrations of solid contaminants remains underexplored. This study explores the effects of sand particles on water-lubricated hydrodynamic journal bearing using Computational Fluid Dynamics (CFD) simulations. The investigation considers key parameters such as contaminant concentrations (up to 24.8 vol.%), rotational speeds (500, 750, and 1000 rpm), and eccentricities (0.3, 0.5, and 0.7). Notably, the presence of solid contaminants significantly impacts the pressure distribution, load-carrying capacity (LCC), and the coefficient of friction (COF) in journal bearing. The highest LCC (approximately 18 kN) occurs under specific conditions: an eccentricity ratio of 0.7, a rotational speed of 1000 rpm, and the highest sand concentration (24.8 vol.%). In comparison, pure water exhibits a significantly lower LCC (only 1.5 kN) under the same conditions. Conversely, the presence of sand particles increases the COF in the journal bearing. Specifically, the highest percentage difference in COF for 24.8 vol.% of sand is 1.53%, while the lowest percentage difference in COF for 6.2 vol.% of sand is 0.57%, both compared to pure water, at an eccentricity ratio of 0.7 and a rotational speed of 1000 rpm.