PRESSURE-DROP OF THE POLYMER MELT FLOW IN A PIPE

Rheological properties of polymer melts are often described with a lin ear model, the two-parameter power-law model in industrial application s, while the real polymer melts behave more or less nonlinearly, parti cularly in the low shear rate regions. In a lot of real flows, such as the simple pipe now, there is even a zero shear rate region. Therefor e, the adequacy of this linear approximation has to be examined, in th is paper, the polymer melt flow in a pipe is studied using the nonline ar three-parameter Powell model. Numerical results are presented in se veral graphs, which can be used in engineering calculations. A compari son with the test data has been given. The restrictions of using the p ower-law model and the impact in handling the experimental data are di scussed.