Behavior of Polymer Solutions and Melts in Shearing and Elongational Flow Using Streak Photography and Birefringence
An experimental analysis has been carried out for the kinematics of a Newtonian (glycerin solution) and a non-Newtonian (polyacrylamide solution) fluid undergoing flow past a radially oriented cylinder in both a converging and uniform flow field. The glycerin and polyacrylamide solutions are found to follow Newtonian and power law behavior, respectively, in Poiseuille flow between parallel plates and the lubrication approximation was found to give an accurate description of the kinematics in the converging flow geometry. The local flow kinematics near the cylinder end were, however, found in the two flow geometries to be the same for both fluids and well described by the solution to the Stokes equations for constant free stream flow past a long slender prolate spheroid. Elongation rates in the vicinity of the cylinder axis are significantly enhanced over those in the mainstream and in a region within about two diameters downstream of the cylinder end the kinematics can be classifed as "strong" becoming "weak" thereafter.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign