Outlet
This node is used to prescribe conditions at boundaries where the two-phase mixture exits the computational domain. The settings available in the node specifies conditions for the entire mixture, as opposed to the Inlet, Outlet and Wall nodes where the conditions for can be specified for each phase individually.
Mixture Boundary Condition
Select Mixture boundary conditionsPressure, no viscous stress, Pressure, normal flow, Velocity, Degassing, or Filtration.
Pressure Conditions
When Pressure, no viscous stress or Pressure, normal flow is selected as the Mixture boundary condition, specify the Pressure p0 (SI unit: Pa) at the outlet. Note that the prescribed pressure should be consistent with the reference pressure level specified at the interface level as well as consistent with present volume forces (including gravity).
Velocity
Select Velocity to specify the Velocity field, continuous phase uc0 (SI unit: m/s) together with the Velocity field, dispersed phase ud (SI unit: m/s) at the outlet.
Degassing and Filtration
Selecting Degassing allows the dispersed phase to exit the domain but prevents the continuous phase from exiting. This is achieved through a pressure (p0), no viscous stress condition for the dispersed phase, in combination with a no penetration condition for the continuous phase.
Selecting Filtration on the other hand allows the continuous phase to exit the domain but prevents the dispersed phase from exiting. This is achieved through a pressure (p0), no viscous stress condition for the continuous phase, in combination with a no penetration condition for the dispersed phase.
Pressure, no viscous stress is the least constraining option and allows the flow to exit the domain in non-normal directions.
Pressure, normal flow restricts the flow to be completely normal to the outlet boundary. This option can influence the flow quite a bit upstream of the inlet.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options.