On the Role Played by the Extensional Behavior of Giesekus Fluids in Plane Stagnation Flow

An exact solution has been found in plane stagnation flow for a viscoelastic fluid obeying the Giesekus model. The flow Was found to tender itself to a local similarity solution in the vicinity of the stagnation point. The solution so obtained Could easily enable one to investigate the effects of parameters such as Reynolds number, Weissenberg number and the mobility factor on the velocity and stress fields. Unlike Newtonian and Maxwellian fluids, the thickness of the boundary layer was found to be a decreasing function of the distance from the stagnation point. It will be shown that this effect may have roots in the extensional behavior of the fluid.