The size-dependent elastohydrodynamic lubrication contact of a coated half-plane with non-Newtonian fluid

Abstract

Based on the couple-stress theory, the elastohydrodynamic lubrication (EHL) contact is analyzed with a consideration of the size effect. The lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian fluid. The density and viscosity of the lubricant are dependent on fluid pressure. Distributions of film thickness, in-plane stress, and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative method. The effects of the punch radius, size parameter, coating thickness, slide/roll ratio, entraining velocity, resultant normal load, and stiffness ratio on lubricant film thickness, in-plane stress, and fluid pressure are investigated. The results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter, stiffness ratio, and coating thickness.

A General Case of a Line Contact Lubricated by a Non-Newtonian Giesekus Fluid

“…The assumptions (11) and ( 23) regarding α and λ 1 remain the same. Then, using the same dimensionless variables as in (16) and asymptotic representations of solution components in which terms proportional to h 1 are omitted, one obtains Equations ( 29)- (32), in which terms proportional to h 1 are omitted. To derive the expressions for u 0 , w 0 , and u 1 , one needs to use asymptotic boundary conditions (34) and (35) following from (66) and (67), in which h 1 (x 0 ) 2 on the lower and upper surfaces should be replaced by h 11 (x 0 ) and h 21 (x 0 ), respectfully.…”

“…An overview and analysis of different fluid rheological models is given in [11,12]. One of the simplest rheological models of non-Newtonian lubricant behavior among generalized Newtonian fluids [13] is the Ree-Eyring model [14][15][16]. Some studies of fluids with complex non-Newtonian rheology were presented in [17][18][19][20][21][22].…”