A computer model of mixed lubrication in point contacts

A numerical model of mixed lubrication is presented in this paper. The idea introduced here is that asperity contact may be viewed as a result of a co ntinuous decrease in film thickness, so that the transition between contact and non-contact is continuous and the same mathematical model should work for both regions. The pressure over the thin films is assumed to obey the R eynolds equation, and the solution of the equation, under the condition of h-->0. is expected to be the same as that predicted by the theory of elasti city. To achieve convergent and stable solutions, the left-hand side terms of the Reynolds equation are switched off when the local film thickness app roaches zero, leading to a reduced Reynolds equation. Pressure distribution s over the entire computation domain are thus obtained through solving a un ified equation system without identifying hydrodynamic or asperity contact regions. Computations were conducted for several example cases and results show that convergent solutions are achievable on different types of roughne ss, over a wide range of lambda ratios (0.01 to infinity), and for differen t slide-to-roll ratios (0.0-2.0). (C) 2001 Elsevier Science Ltd. All rights reserved.