The Fluid Properties node adds the momentum and continuity equations solved by the physics interface, except for volume forces which are added by the Volume Force node. The node also provides an interface for defining the material properties of the fluid.

Volume Force is described for the Pipe Flow interface in the Pipe Flow User’s Guide.

Enter a value for the and Background mean flow pressure p0 (SI unit: Pa). This pressure will also serve as input the material parameters that depend on the pressure.

Enter a value or expression for the Background mean flow velocity u0 (SI unit: m/s)

Physically sound background variables for the pressure p0 and velocity u0 can be obtained by solving a Pipe Flow model on the same geometry.

Select a Fluid model—Linear elastic (the default).

The default Density ρ (SI unit: kg/m3) and Speed of sound cs (SI unit: m/s) use the values From material. For User defined enter different values or expressions.