The free surface on a liquid between cylinders rotating at different speeds part II

This paper is a further contribution to our work on the Weissenberg effect. One goal of our work is to show how the free-surface deformations on a viscoelastic fluid which is sheared between two concentric rotating cylinders can be used to determine rheological data about the fluid. In this paper we report the results of an experimental program in which free surface shapes have been measured on three viscoelastic fluids undergoing shearing in an apparatus consisting of a stationary outer cylinder and four interchangeable rotating inner cylinders. Experimentally-measured profiles are compared with profiles predicted from second-order theory, and found to be in excellent agreement for STP and TLA-227 in the range of applicability of the second-order theory, but there is some disagreement in the results for a 2% solution of polyacrylamide in 49% water −49% glycerin.