When simulating a membrane using the porous jump sub-model, it is necessary to define a dataset for the material parameters in Equation 8–17 by performing the following steps:
Click the Define material datasets item in the Define sub-models menu.
Define material datasets
The Define material datasets menu opens.
Click the Create a new material dataset item.
Create a new material dataset
A panel opens in which you can revise the default value for New value, which will act as the name for the dataset. Click in the panel to close it. Then read any warning panels that open, click in these panels, and take any necessary corrective actions. The <material dataset name> menu will then open (where <material dataset name> is the name you entered in the previous panel).
Click the Add data item.
Add data
The Add data to a material dataset menu will open, where you can specify which material parameters will be defined in the dataset.
Click Add porous medium and fluid viscosity.
Add porous medium and fluid viscosity
For nonisothermal flows, click Add temperature dependence of viscosity.
Add temperature dependence of viscosity
Click Upper level menu to return to the previous menu.
Define the material parameters for Equation 8–17.
Define the permeability (
) of the porous membrane and the reference
viscosity (
) of the fluid as it flows through the membrane.
Porous medium and fluid viscosity
The Porous medium and fluid viscosity menu will open.
Click the Modify permeability item.
Modify permeability
Enter a New value for the permeability in the panel that opens, and click .
Click the Modify fluid viscosity item.
Modify fluid viscosity
Enter a New value for the fluid viscosity in the panel that opens, and click . The fluid viscosity is represented by a single number, and should be selected in accordance with the actual fluid viscosity and the geometry of the porous membrane.
Click Upper level menu to return to the previous menu.
For nonisothermal flows, define the relationship between temperature and the viscosity of the fluid as it flows through the porous membrane (
).
Temperature dependence of viscosity
The Temperature dependence of viscosity menu will open. Select the law you want to use, and specify the relevant parameters:
Click No temperature dependence if you do not want the viscosity to be temperature-dependent (that is,
). No further inputs are required. Click Arrhenius approximate law to define
using Equation 10–20 with temperatures at constant
shear rate. The inputs for this law are 
and 
. Click Arrhenius law to define
using Equation 10–18 with temperatures at constant shear rate. The inputs for
this law are 
, 
, and 
. To specify 
as an absolute temperature, set the
temperature shift 
to 0. Otherwise, set 
to the appropriate temperature shift and
then specify 
relative to 
. Click Fulcher dependence to define
using Equation 10–21. The inputs for this law are 
, 
, and 
. Click WLF dependence to define
using the WLF equation (Equation 10–22)
based on shear rate (that is, with only a vertical shift in
the 
- 
diagram). The inputs for this law are
, 
, 
, and 
. The default values for 
and 
are appropriate for many polymer
processing applications.
Click Upper level menu repeatedly to return to the Define material datasets menu, and then repeat the steps 2.–4.(b) for each additional material dataset you want to create.