On the slider-bearing flow of a viscoelastic fluid

Abstract

This paper considers the slider-bearing flow of a model viscoelastic fluid. It is shown that the standard lubrication theory leads to some results which are in good agreement with a full numerical solution by a Boundary Element Method. The normal load per unit width is enhanced by a term of O( N 1 L), where N 1 is the first normal stress difference and L is the bearing length, while the drag force remains essentially unchanged. This leads to a reduction in the frictional coefficient, which increases with Weissenberg number. The full slider bearing flow problem consists of three regions: the inlet flow, the bearing flow, and the outlet flow. The two free surfaces associated with the inlet and outlet flows must be found as parts of the solution. The full problem is unsteady, and the main effect of the free surfaces is to decrease the load-carrying capacity of the bearing. A simple global balance of momentum can account for the observed numerical behaviour.