The Goddard expansion and the kinetic theory for solutions of rodlike macromolecules

The Goddard memory‐integral expansion for the stress tensor of viscoelastic fluids differs from previous expansions in that it uses a deformation rate referred to a co‐rotating reference frame. It is shown how to get the kernel functions in the Goddard series in terms of the structural parameters occurring in the kinetic theory of macromolecular solutions.

That the series has much better convergence properties than previously used expansions is demonstrated by comparison with exact kinetic theory results for steady‐state shear flow and elongational flow.