Viscoelastic flow due to a rotating disc enclosed in a cylindrical casing - (Influence of aspect ratio)

This paper deals with viscoelastic flows due to a rotating disc enclosed in a cylindrical casing with variable axial clearances. The behavior of visco elastic flows due to a rotating disc has been characterized based on an exp erimental study using a flow visualization technique and numerical simulati on using several models for constitutive equations. The pattern of secondar y flow for the region of competition between the elastic force and the iner tial force is a radially arranged double-cell structure (Type DC 1 ') which differs from Type DC 1. Type DC 2 was reproduced qualitatively by numerica l simulation with Giesekus and Phan Thien-Tanner models, but not by numeric al simulation with the upper convected Maxwell model or power-law model. Fu rthermore, the profiles of the tangential velocity component V-theta and th e radial velocity component V-r obtained by numerical simulation with the G iesekus and Phan Thien-Tanner models for small H/R agreed with those measur ed using particle tracking velocimetry (PTV).