A default Outflow Boundary subnode is added to the Asymptotic Far-Field Radiation. The outflow condition has to be added where the background mean flow leaves the computational domain to ensure that vorticity and entropy waves are not created here.

When solving, the interface can return an error if the condition is added where there is no background mean flow, u0 = 0. Here certain terms evaluate to zero. Adding the condition at boundaries where the background mean flow enters the computational domain can result in unphysical results.