Using COMSOL Multiphysics to Model Viscoelastic Fluid Flow

B.A. Finlayson
Department of Chemical Engineering, University of Washington

Viscoelastic fluids have first normal stress differences even in rectilinear flow. Thus, they are more complicated than purely viscous non-Newtonian fluids modeled as a power-law model or Carreau model.

Viscoelastic effects must be included when modeling the flow of polymer melts and concentrated polymer solutions in situations for which the normal stresses matter. The extrudate swell problem involves a free surface whose location must be obtained such that it is a streamline in the jet.

This paper describes some key parameters of polymers, creates some models of viscoelastic fluids, and shows how to use COMSOL Multiphysics to solve such models.