Influence of Viscosity Changes on Magneto-Hydrodynamic Squeeze Film Lubrication Between Rough Circular Plates Using Couple-Stress Fluid

Abstract

This paper examines the influence of viscosity fluctuations and magnetic fields on squeeze film lubrication between rough circular plates using a couple-stress fluid. A modified Reynolds equation is derived based on Christensen’s stochastic theory to account for surface roughness. The analysis specifically investigates two types of one-dimensional roughness patterns: radial and azimuthal. Expressions for pressure, load-carrying capacity, and squeeze film time are formulated, with discussions centred on the variation of various non-dimensional parameters, supported by 2D and 3D graphical representations. The results reveal that radial roughness tends to reduce, while azimuthal roughness increases, the pressure, load-carrying capacity, and squeeze film time. Furthermore, the presence of viscosity variation, couple stress, and magnetic fields significantly enhances these parameters compared to the smooth plate scenario. The study also calculates the relative percentage changes for these attributes, offering valuable insights for design engineers to optimize bearing performance by selecting appropriate surface structures, magnetic fields, and lubricant additives to prolong bearing life.