Kinematics of two-sided surface features in elastohydrodynamic lubrication

A Newton-Raphson scheme is used to solve the transient elastohydrodynamic l ubrication line-contact problem with two-sided features and waviness for mo derate loads. Surface features such as dents, bumps and waviness are studie d; pressure and film thickness distributions in time are presented for each case. The analytical solution of Greenwood and Morales-Espejel for transie nt one-sided waviness is extended for two-sided waviness and the results co mpared with numerical simulations; they show again that the transient solut ion is made of two steady state components (one from each surface) travelli ng with each surface velocity and two propagated waves coming from the inle t (pumping-up effect from each surface) travelling with the average velocit y of the lubricant. The results are in good agreement with theoretical pred ictions; they also establish the importance of the complementary function's shift of phase to determine the distributions of the pressure and the film thickness with time for a fixed location.