An Average Flow Model for Couple Stress Fluids

Abstract

The interactions of surface roughness and flow rheology of couple stress fluids on thin film lubrication problems are modeled. The generalized average Reynolds equation as well as the flow factors is derived. The effects of couple stress parameters (l), the standard derivation of surface roughness (σ i ), the Peklenik number (γ i), and the roughness orientation angle (θ i) on the flow factors (φ p ij , φ s ij) are discussed. In results, the related Reynolds-type equations and flow factors for Newtonian fluids, power-law non-Newtonian fluids, mixtures of Newtonian and power-law non-Newtonian fluids, and couple stress fluids are tabulated.