The Fluid Properties node is always present and adds the momentum and mass balance equations solved by the physics interface. If volume forces are needed in the model, they should be added by a
Volume Force node. The node also provides settings for defining the material properties of the fluid. If a Liquid-Gas option is selected in the Pipe Flow node settings, properties for both liquid and gas can be entered here.
This subsection displays when Newtonian>Single phase is selected as the
Fluid model for the Pipe Flow interface.
The default Density ρ (SI unit: kg/m
3) 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 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.
This section displays when Newtonian is selected as the
Fluid model for the Pipe Flow interface and then
Gas-Liquid, friction factor multiplier or
Gas-Liquid, effective Reynolds number are also chosen.
Select the Liquid material—
Edge material (3D components) or
Boundary material (2D components). If you have more than one material added to the model, you can toggle this setting between the different designated materials.
The default Density ρL (SI unit: kg/m
3) uses the value
From material. You can change this to
User defined to enter a different value or expression.
The default Dynamic viscosity μL (SI unit: Pa·s) uses the value
From material and describes the relationship between the shear rate and 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.
This section displays when Newtonian is selected as the
Fluid model for the Pipe Flow interface and then
Gas-Liquid, friction factor multiplier or
Gas-Liquid, effective Reynolds number are also chosen.
Select the Gas material—
Edge material (3D components) or
Boundary material (2D components). If you have more than one material added to the model, you can toggle this setting between the different designated materials.
The default Density ρG (SI unit: kg/m
3) uses the value
From material. For
User defined enter a different value or expression.
The default Dynamic viscosity μG (SI unit: Pa·s) uses the value
From material and describes the relationship between the shear rate and shear stresses in a fluid.
This section displays only when Newtonian is selected as the
Fluid model for the Pipe Flow interface and the
Gas-Liquid, effective Reynolds number is also chosen.
The default is the Extended Einstein which is considered the most accurate method for a large range of gas fractions. The list of options include