Multiple Integral Constitutive Equations in Unsteady Motions and Rheometry

The use of the integral fluid of order three to predict some simple nearly viscometric unsteady flows of viscoelastic liquids, driven by periodic forcing, is discussed. Flow enhancement effects, due to the parallel and orthogonal superposition of oscillatory and simple shear fields, are predicted. It is shown that it is feasible to determine the constitutive constants involved from a series of experiments of rheometry.