RECTILINEAR MOTION OF A MAXWELL FLUID

Abstract

We consider the steady rectilinear motion of a Maxwell fluid in straight tubes of arbitary cross section. This type of motion in a circular tube is possible in the absence of body forces. The velocity at any point of a croos section is less than the corresponding velocity of a Newtonian fluid, the midstream velocity being the same in both cases. We derive the conditions necessary for the maintenance of a purely rectilinear flow in a tube of arbitrary section in the absence of body forces. These conditions restrict the form of the strain energy function in its dependence on the strain  invariants.