This is the default setting of the Fracture Flow interface, and implements the fracture flow as described in Equation 4-31. The values for the fluid properties (density and dynamic viscosity) can be taken from the material node or be defined by an arbitrary expression. The same can be done for the fracture’s properties, such as porosity and permeability. Enter the fracture’s thickness in the corresponding field.

The governing equation takes the slightly different form, compared to Equation 4-31:

where Sf is the fracture storage coefficient (SI unit: 1/Pa).