Boundary conditions for c-grid airfoil
 

Hi,

I'm trying to test my code on flow past an airfoil. My code is FVM cartesian structured fractional step NS solver with collocated variables. The eqns are solved in phyical space, no transformation.

I've generated a half NACA0012 c-grid using Meshpilot (since it's symmetrical). The northern side of my curved structured grids correspond to the inlet and top boundary, western to the symmetry plane, eastern to outlet and southern to foil surface and symmetry.

However, I'm not very sure how the BC can be implemented, after reading quite a few papers.

Here's my choice of BC: surface of foil: u=0,v=0,d(vel)(n)/dn=0 inlet:u=u(infinity),v=0 top: du/dn=0,v=0 outlet: du/dn=0,dv/dn=0 dp/dn=0 on all sides d(vel)(n)/dn=0 because diffusive flux into wall is 0. Pls comment on whether all these are suitable BC

The inlet and top is now a half "c" shape(due to sym), which is the northern side. So how do I implement these 2 different BC on the same side? I guess at some horizontal face, u is no longer equal to u(infinity). is that right?

hope that I've posed my qn in a clear fashion. thank you very much!

Re: Boundary conditions for c-grid airfoil
 

hi,

your boundary conditions seems to be correct, u=u (infinity) is correct coz there is no disturbance assumed to the flow at infinity (analogous to Farfield conditions) your stagnation point BC also is fine, but you might m=want to cheack on the BC on dp/dn=0.

You can refer papers on the AIAA Journal regarding the closed loop control for stall conditions for an Airfoil, where you might get the answer, i think the author name is Volkan Kamaci. You can check on tht.