The inletOutlet boundary condition is normally the same as zeroGradient, but it switches to fixedValue if the velocity vector next to the boundary aims inside the domain (backward flow). The value of that fixedValue is inletValue. See figure ().
Figure: The meaning of inletOutlet boundary condition
U:
boundaryField
{
".*_outlet"
{
type inletOutlet;
value $internalField;
inletValue uniform (0 0 0);
}
}
k, omega, epsilon, T:
boundaryField
{
".*_outlet"
{
type inletOutlet;
value $internalField;
inletValue uniform 0;
}
}