The Fluid Properties node adds the momentum and continuity equations to solve for free flow in nonporous domains. The node also provides an interface for defining the material properties of the fluid.
By default, the single-phase flow interfaces are set to model isothermal flow. Hence, the Temperature is
User defined and defaults to 293.15 K. If a Heat Transfer interface is included in the component, the temperature may alternatively be selected from this physics interface. All physics interfaces have their own tags (
Name). For example, if a Heat Transfer in Fluids interface is included in the component, the
Temperature (ht) option is available.
The default Absolute pressure pA is
p+pref where
p is the dependent pressure variable from the Navier–Stokes equations, and
pref is from the user input defined at the physics interface level. When
pref is nonzero, the physics interface solves for a gauge pressure. If the pressure field instead is an absolute pressure field,
pref should be set to 0.
The Absolute pressure field can be edited by clicking
Make All Model Inputs Editable (
) and entering the desired value in the input field.
The Dynamic viscosity μ describes the relationship between the shear rate and the shear stresses in a fluid. Intuitively, water and air have low viscosities, and substances often described as thick (such as oil) have higher viscosities.