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In certain applications where the lubricant is subjected to
rapidly changing conditions along its flowing path (such as an
elastohydrodynamic contact), the inherently time dependent nature
of the lubricant may be significant. The simplest type of model
to correctly account for such time dependence is the second-order
fluid, which is a systematic small departure from Newtonian
behavior, involving higher order rate-of-rate-of strain tensors.
As in a companion paper using the Maxwell model, the formalities
of applying such a model to thin film flow are emphasized. Using
a regular perturbation in the Deborah number, with the
conventional lubrication solution as the leading term, a solution
can be obtained. Viscoelasticity may raise or lower pressure
depending on the nature of the edge boundary conditions.
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