Setting Up Viscous Flow Physics

The Viscous Flow model appears alongside the Segregated and Coupled Flow models for a physics continuum.

To select the physics models:

  1. For the physics continuum, Continua > Physics 1, select the following models, in order:
    Group Box Model
    Enabled Models Three Dimensional (Selected automatically)
    Time Steady
    Material Liquid
    Flow

    Viscous Flow

    Constant Density (Selected automatically)

    Laminar (Selected automatically)

    Optional Models Residence Time
    Rheology Generalized Newtonian
An important step in preparing a viscous flow simulation is choosing the rheology model that best represents the fluid that you are working with. In this tutorial, the viscous behavior of liquid polystyrene fits the characteristics of a Non-Newtonian Generalized Carreau-Yasuda Fluid. Here, the model parameters were previously tuned to match the fluid behavior.
  1. Select Physics 1 > Models > Liquid > H2O and rename it to Polystyrene.
  2. Select Polystyrene > Material Properties and set the following properties:
    Node Property Value
    Density > Constant Value 1500 kg/m^3
    Dynamic Viscosity Method Non-Newtonian Generalized Carreau-Yasuda Fluid
    Non-Newtonian Generalized Carreau-Yasuda Fluid Power Constant 0.25
    a Parameter 2
    Zero Shear Viscosity 1100000 Pa-s
    Infinite Shear Viscosity 3000.0 Pa-s
    Relaxation Time 8.0 s