When generating a C grid around the airfoil what boundary condition do we apply along the top and bottom cut.I have not been able to find any information on the implementation of boundary condition along those lines.

Thanks a lot

add two row of halo grid for bottom and top cut and copy value of bottom cut to halo row of top cut and vise versa(we don't have physical boundary in cut and so this boundary is virtual)

Or i believe you can just deal with it directly since there is actually no boundary. u'll 've to modify the cell connection tt's all.

btw, u can look at blazek CFD book

http://www.amazon.com/Computational-.../dp/0080430090

Since there are two points for each point (if you get that) on the wake cut. An accepted route to go is simply to use the average of the points on either side of it, i.e.

Q(n=1) = Q(n=2) + Q(n=nmax-1) / 2 Q(n=nmax) = Q(n=1)