Use the Fluid node to define the density, dynamic viscosity, and heat convection and conduction properties.

The default Density ρ (SI unit: kg/m3) uses the value From material. For User defined enter a different value or expression.

The default Dynamic viscosity μ (SI unit: Pa·s) uses the value From material and describes the relationship between the shear rate and the shear stresses in a fluid. Intuitively, water and air have a low viscosity, and substances often described as thick, such as oil, have a higher viscosity.

Enter a value or expression for Dc (SI unit: m2/s). The default is 1 × 10-9 m2/s.

Select a Dispersion model — User defined (the default), Taylor (laminar, circular cross section), or Taylor (turbulent, circular cross section). For User defined, enter a value or expression for the Dispersion coefficient DD (SI unit: m2/s). The default is 0 m2/s. For detailed information about dispersion, see the theory section Dispersion.

The default Heat capacity at constant pressure Cp (SI unit: J/(kg·K)), Ratio of specific heats γ (dimensionless), and Thermal conductivity k (SI unit: W/(m·K)) all use values From material. For User defined enter different values or expressions.