The present work aims at studying mainly the wall shear stress of
a laminar steady flow of an incompressible Newtonian fluid which
is conveyed through a collapsed tube with a straight centreline.
This tube is composed of a tapered segment, a contact segment
where the opposite walls touch and a reopening segment. The tube
geometry and steady flow characteristics are obtained from
measurements in a collapsed tube. The Navier-Stokes
equations associated with the classical boundary conditions are
solved using the finite element method. The tridimensional flow
results from the tube configuration. In particular, the flow
consists of two side-jets due to two tear-drop shaped outer
passages in the downstream contact segment associated with
reversed flow. In order to compute both the stream-wise and
cross-wise components of the shear stress on the wall, a local
basis is defined in each wall node. Downstream of the contact
segment, flow is separated in two jets which are studied though
the help of the velocity field and the wall shear stress.