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 viscoelastic flows due to a rotating disc has been characterized based on an experimental study using a flow visualization technique and numerical simulation using several models for constitutive equations. The pattern of secondary flow for the region of competition between the elastic force and the inertial force is a radially arranged double-cell structure (Type DC 1') which differs from Type DC 1. Type DC 2 was reproduced qualitatively by numerical simulation with Giesekus and Phan Thien-Tanner models, but not by numerical simulation with the upper convected Maxwell model or powerlaw model. Furthermore, the profiles of the tangential velocity component V_θ and the radial velocity component V_γ obtained by numerical simulation with the Giesekus and Phan Thien-Tanner models for small H/R agreed with those measured using particle tracking velocimetry (PTV).