60 likes | 74 Views
Example: Polymer Extrusion. Polymer extrusion. Non-Newtonian flow, Carreau viscosity. S tudy the influence of shear rate dependent viscosity . L inear polystyrene solution . Carreau viscosity model. Polymer extrusion - Equations. Equations. M omentum and continuity equations.
E N D
Polymer extrusion Non-Newtonian flow, Carreau viscosity • Study the influence of shear rate dependent viscosity. • Linear polystyrene solution. • Carreau viscosity model .
Polymer extrusion - Equations Equations • Momentum and continuity equations. • The viscosity is dependent on the shear rate • The Carreau-viscosity is given by
Polymer extrusion - Geometry Geometry Due to rotational symmetry, we can reduce the model dimensions from 3D to axisymmetric 2D.
Polymer extrusion - Results Velocity field • The average velocity is substantially lower at the outlet compared to the inlet, due to the rotational symmetry.
Polymer extrusion - Results Non-Newtonian viscossity • Large variations in the contraction between the piston and the walls of the device. • The narrow channel generates large shear rates close to the walls.