On the flow of non-Newtonian polymer solutions

Abstract

This paper presents a study of the flow of non-Newtonian polymer solutions. The predictions obtained by a numerical technique are compared with a derived analytical solution and with experimental measurements. Poly(vinyl chloride) (PVC) solutions in cyclohexanone were prepared in the concentration range between 16.67 and 20.24% w/w to determine the shear viscosity functions by means of a Brookfield RVT viscometer. A computer code was employed to simulate the laminar flow of a 20% w/w solution in a pipe. Results for the fully developed flow are in excellent agreement with the derived analytical solution and are also verified experimentally by measuring fluid velocity in a real pipe, using a laser-Doppler anemometer. Furthermore, the laminar flow of a Newtonian and an Ellis fluid in a pipe as well as the flow of a power law fluid in a sudden enlargement are simulated with the same code, giving predictions consistent with theory. It is concluded that computer simulation is a powerful and accurate technique for predicting the flow behavior of non- Newtonian polymer solutions.