Analysis of Nanoparticle Additive Three-layered Journal Bearing

This work presents an analysis of nanoparticle additive three-layered journal bearing. A three-layered fluid film of different Newtonian dynamic viscosities at the surface (journal and bearing adjacent fluid film layers) and core is considered in the analysis. The modified classical Reynolds equation is derived taking into consideration of surface adjacent and core fluid film layer’s film thickness and viscosity of nanoparticle additive fluid. All the three fluid film layers are assumed to be Newtonian. The Reynolds boundary conditions are used in the steady state analysis. Pressure distribution is obtained by integration of modified Reynolds equation using Reynolds boundary conditions.
Load capacity parameter and coefficient of friction are analyzed with surface (journal or bearing) adjacent fluid film layer thickness ratio using (i) dynamic viscosity ratio of surface to core layer; (ii) dynamic viscosity ratio of core to surface layer; and (iii) nanoparticle volume fraction. Nanoparticle additives increase lubricant viscosity and hence influence the fluid film bearing performance characteristics.

Based on the analysis presented in this work, higher non-dimensional load capacity (W) is obtained for a three-layered journal bearing operating with (i) higher dynamic viscosity of fluid film layers and (ii) nanoparticle additive fluid. The coefficient of friction (Cf) decreases with high viscosity surface adjoining layer fluid film. However, coefficient of friction (Cf) for a three-layered journal bearing is not influenced by the addition of nanoparticles.