Manufacturing Solutions

# Outflow Boundary

The Outflow boundary type is used to impose conditions at the domain outlet.

Syntax

OutflowOutlet{ {(X_Velocity = Ux| X_Traction = tx ,

Y_Velocity = Uy| Y_Traction = ty,

Z_Velocity = Uz| Z_Traction = tz),

([Pressure = Po],)

(Temperature To | HeatFlux = qout )}

Comments

"Outlet" is the name of the user-specified outflow boundary. For each component of the momentum equation, you must specify either the velocity or the tractions. The X_Velocity, Y_Velocity, and Z_Velocity entities specify the primary degrees of freedom for each component of the momentum equation. The X_Traction, Y_Traction, and Z_Traction entities specify the secondary degrees of freedom. Pressure is specified only if tractions are imposed. Either Temperature or HeatFlux is specified for the energy equation when solving non-isothermal flows. The velocities, tractions, pressure, temperatures, and heat fluxes can be input as a function of space and time.

Valid data types for each field are given in the following table:

## Variable Name |
## Description |
## Valid Data Types |

Velocity (Ui) |
Velocity component (i=x,y,z) |
CONSTANT, EXPRESSION f(x,y,z,t) |

Traction (ti) |
Traction component (i=x,y,z) |
CONSTANT, EXPRESSION f(x,y,z,t) |

Pressure (P) |
Static pressure |
CONSTANT, EXPRESSION f(x,y,z,t) |

Temperature (T) |
Static temperature |
CONSTANT, EXPRESSION f(x,y,z,t) |

HeatFlux (q) |
Magnitude of surface heat flux |
CONSTANT, EXPRESSION f(x,y,z,t) |

Note: | Pressure must be specified on at least one element face of either the Inflow or Outflow boundary. |