Non-swirling axisymmetric flow of the ω-D fluid

In this paper a constitutive equation for the extra stress tensor τ is considered, which can be used for steady axisymmetric flows when u _ϕ=0 (non-swirling). It is explicit with coefficients which, in case of incompressibility, depend only upon three invariants. As such it should prove useful in numerical calculations, especially so if used in its simplest form, namely the quasi-Newtonian fluid. Here, a purely viscous code can be used. The constitutive equation is self-consistent and receives additional justification from the fact that any constitutive equation is bound to result in the form proposed if the flow is a constant stretch history flow. Received: 30 March 1998 Accepted: 6 August 1998