Fluid materials and their physical properties determine the fluid response. You create the fluid material in the Property module. Depending on the analysis, you may need to specify the following properties:
Density
Fluid density must be defined for fluids in an Abaqus/CFD analysis; it is required for transient Navier-Stokes computations. The fluid density is considered constant for incompressible flows.
Viscosity
You must specify the viscosity for viscous flows, and only a constant viscosity is supported.
Specific heat
For an incompressible fluid dynamic analysis that includes an energy equation, you must define the specific heat and thermal conductivity. A specific heat using constant pressure is required; you can define the specific heat using constant pressure, or you can define the specific heat using constant volume and specify the ideal gas constant.
Thermal conductivity
Only a constant isotropic thermal conductivity is supported.
Thermal expansion coefficient
The coefficient of thermal expansion is used with the Boussinesq approximation for natural convection flows.
Permeability
You can specify isotropic permeability (with dependence only on porosity) or permeability using a Carman-Kozeny relation.
