Vortices in non-Newtonian fluids

The research carried out under the subject contract has been directed to the analysis of the manner in which the vorticity in an incompressible viscoelastic fluid propagates and decays. The fluids considered are such that for shearing flows the shear stress at an instant of time t depends linearly on the history of the velocity gradient in the fluid for all times up to and including t. Although in the problems considered most of the analysis is carried out for arbitrary linear dependence of the shear stress in the velocity gradient history, illustrative numerical results are obtained for the case when the fluid is Maxwellian and, for purposes of comparison, when it is Newtonian.