Example of inflow/outflow boundary conditions

Click here for the previous page on the inlet boundary conditions
Click here for the previous page on the outlet boundary conditions

This example is defined for a 2D geometrical configuration. The size of the domain is The flow is homogeneous (no multi-species gas) An inlet is located at the down left side of the domain (red line on the figure). An outlet is located at the top right side of the domain (green line on the figure). Conditions are constant in time

(inlet in red line, outlet in black line, walls in green lines)

Inflow data

Example 1

The flow is homogeneous (no multi-species gas) Conditions are constant in time

&Inlet_Boundary_Conditions
Type_of_BC= "INLET", Direction_Normal_Plan= 1 ,
Plan_Location_Coordinate= 0.0 ,
Start_Coordinate_of_First_Span = 0.0, End_Coordinate_of_First_Span = 0.5,
Start_Coordinate_of_Second_Span= 0.0 , End_Coordinate_of_Second_Span= 0.0 ,
Flow_Direction= 1 ,
Normal_Velocity_Reference_Value= 1.0 ,
Temperature_Reference_Value= 293.0 ,
Density_Reference_Value= 1.2,
Define_Velocity_profile= 0 ,
End_of_Data_Block= .true. /

Example 2

Not for the release SUNFLUIDH_EDU

The flow is homogeneous (no multi-species gas) The temperature and the density are constant. The normal velocity component is time-dependent : The function is sinusoidal. The mean value of the time function is given by “Normal_Velocity_Reference_Value”. the frequency is 10 Hz The magnitude is 40% of the mean inlet velocity

&Inlet_Boundary_Conditions
Type_of_BC= "INLET", Direction_Normal_Plan= 1 ,
Plan_Location_Coordinate= 0.0 ,
Start_Coordinate_of_First_Span = 0.0, End_Coordinate_of_First_Span = 0.5,
Start_Coordinate_of_Second_Span= 0.0 , End_Coordinate_of_Second_Span= 0.0 ,
Flow_Direction= 1 ,
Normal_Velocity_Reference_Value= 1.0 ,
Temperature_Reference_Value= 293.0 ,
Density_Reference_Value= 1.2,
Define_Velocity_profile= 0 ,
Time_Fct_Name= "Sinus" , Time_Fct_Threshold= 0.0 ,
Time_Fct_Time_Scale= 0.1 , Time_Fct_Magnitude= 0.4 ,
End_of_Data_Block= .true. /

Outflow data

Example 1

The outflow is based on the mass flowrate conservation. The normal pressure gradient is zero (Neumann boundary condition).

&Outlet_Boundary_Conditions

Type_of_BC= "OUTLET", Direction_Normal_Plan= 1 ,
Plan_Location_Coordinate= 1.5 ,
Start_Coordinate_of_First_Span = 0.5 , End_Coordinate_of_First_Span = 1.0 ,
Start_Coordinate_of_Second_Span= 0.0 , End_Coordinate_of_Second_Span= 0.0 ,
Flow_Direction= 1 ,
End_of_Data_Block= .true. /

Example 2

Not for the release SUNFLUIDH_EDU

The outflow is based on pressure conditions. The (dynamic) pressure value is given by “Pressure_Reference_Value”. It is imposed out of the domain and located at a distance “Length_Scale” from the outflow plan (Robin condition). Keep in mind that the pressure is here related to the dynamics, not to the thermodynamics of the flow. It is therefore defined from a reference value which can be null.

&Outlet_Boundary_Conditions

Type_of_BC= "FREEBC", Direction_Normal_Plan= 1 ,
Plan_Location_Coordinate= 1.5 ,
Start_Coordinate_of_First_Span = 0.5 , End_Coordinate_of_First_Span = 1.0 ,
Start_Coordinate_of_Second_Span= 0.0 , End_Coordinate_of_Second_Span= 0.0 ,
Flow_Direction= 1 ,
Pressure_Reference_Value = 0.0 , Length_Scale= 0.2 ,
End_of_Data_Block= .true. /

Click here for the previous page on the inlet boundary conditions
Click here for the previous page on the outlet boundary conditions