Application of IF-WS2 nanoparticles in lubricants to enhance load carrying capacity of plain bearings

Abstract

Hydrodynamic journal bearings have been widely used in heavy industry machinery to support rotating shafts due to their superior durability, low maintenance cost, and excellent load capacity. Inorganic fullerene-like tungsten disulfide nanoparticles (IF-WS2 NPs) are the most studied additive for lubrication purpose due to their excellent mechanical characteristics. In this work, a numerical simulation approach with discrete phase modeling of suspended nanoparticles was used to evaluate the load carrying capacity of journal bearings in heavy industry where the normal loads are very high relative to the bearing footprint. For accurate simulation, nanofluid viscosity was calculated using available empirical models, considering the aggregation effect of NPs. To characterize the aggregations of nanoparticles, scanning electron microscopy (SEM) imaging of the nanofluid samples were employed. The simulated pressure distribution was then used to calculate the load capacity of the bearing. The results show about 20% improvement of load capacity at 5% weight fraction of IF-WS2 nanofluid.