[Junjunan]

Dear all,

I make a code for Navier-stokes equations
but, I confuse about the boundary conditions at the viscous flow
particularly at the outflow boundary
for example, at supersonic outflow, when I do the Euler equations, there's no problem. all properties extrapolated.
but how about Navier-Stokes? in the region near the wall is subsonic, then I have to specified 1 property or no?
Please somebody help me, thank for your information