Fluid and Matrix Properties
Use the Fluid and Matrix Properties node to define which domains contain porous material and to define the porous matrix properties, such as the porosity and permeability in these domains. The Forchheimer Drag subnode is available from the context menu (right-click the parent node) or from the Physics toolbar, Attributes menu.
Domain Selection
Choose domains from the Selection list, to solve for porous media flow governed by the Brinkman equations. In the domains not selected, the Free and Porous Media Flow interface solves for laminar flow governed by the Navier-Stokes (or Stokes) equations.
Porous Matrix Properties
The default Porous material uses the Domain material (the material defined for the domain) for the porous matrix. Select another material as needed.
Porosity
The default Porosity εp (a dimensionless number between 0 and 1) uses values From material as defined by the Porous material selection. For User defined enter another value or expression. The default is 0.
In this node you specify the porosity εp, whereas in other nodes the volume fraction of solid material θp=1-εp is required instead. See Porous Medium in the Heat Transfer Module User’s Guide for an example.
Permeability
The default Permeability κbr (SI unit: m2) uses values From material as defined by the Porous material selection. For User defined select Isotropic, Diagonal, Symmetric, or Anisotropic from the list and then enter other values or expressions. The components of a permeability in the case that it is a tensor (κxx, κyy, and so on, representing an anisotropic permeability) are available as fp.kappaxx, fp.kappayy, and so on (using the default name fp). The default is 0 m2.
Source Term
Enter a value or expression for an optional mass source (or sink) Source term Qbr (SI unit: kg/(m3·s)). This term accounts for mass deposit and mass creation within domains. The physics interface assumes that the mass exchange occurs at zero velocity.
Effective Mass Transport Parameters
A correction factor (Bruggeman, No Correction, or User defined) to the mass transport parameters (defined in the Transport Properties node) can be applied for the porous domain. Species diffusivities and mobilities are automatically adjusted by the porous media corrections. For User defined enter a value or expression for the Conversion factor feff. The default is 1. Species diffusivities and mobilities are automatically adjusted by the porous media corrections.