The Fluid Properties node adds the momentum and continuity equations solved by the physics interface. For the viscoelastic fluids, the constitutive relations for the extra elastic stress tensor are also added. The node also provides an interface for defining the material properties of the fluid.
Viscoelastic (default),
Specify dynamic viscosity and
Inelastic non-Newtonian options are available. If
Viscoelastic constitutive relation is selected, the
Fluid Properties node also adds the variables and equations for the components of the elastic stress tensor.
For Viscoelastic constitutive relation, specify
Solvent viscosity μs and select a
Material model —
Oldroyd-B,
Giesekus, or
FENE-P. Viscoelastic material can be described as consisting of one or more branches. For each viscoelastic branch, enter parameters in the table. See the setting for each viscoelastic model that follows.
For Oldroyd-B enter the model parameters in the table. In each
Branch raw enter the polymer viscosity
μem in the
Viscosity column, and the relaxation time
λem in the
Relaxation time column.
For Giesekus, in each
Branch raw enter the polymer viscosity
μem in the
Viscosity column, the relaxation time
λem in the
Relaxation time column, and the mobility factor
αem in the
Mobility column.
For FENE-P, in each
Branch raw enter the polymer viscosity
μem in the
Viscosity column, the relaxation time
λem in the
Relaxation time column, and the extensibility parameter
Lem in the
Extensibility column.
To display this section, click the Show More Options button (
) and select
Advanced Physics Options in the
Show More Options dialog box. Select shape function type for the components of the auxiliary viscoelastic tensor. The default setting is
Linear.
To display this section, click the Show More Options button (
) and select
Advanced Physics Options in the
Show More Options dialog box. Enter initial values or expressions for the components of the auxiliary viscoelastic tensor. The initial values can serve as an initial condition for a transient simulation or as an initial guess for a nonlinear solver. The default values are 0 N/m
2. Note, that if several branches are specified, the initial values entered above are applied to all branches.