The time-dependent, two-dimensional compressible Newtonian flow over the reservoir-die region is solved assuming that slip occurs along the die wall following a nonmonotonic slip law. The combination of compressibility and nonlinear slip leads to self-sustained oscillations of the pressure drop and of the mass flow rate at constant piston speed, when the latter falls into the unstable negative slope regime of the flow curve. The effect of the reservoir volume on the amplitude, the frequency and the waveform of the pressure oscillations is studied and comparisons are made with experimental observations concerning the stick-slip polymer extrusion instability.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.