For cell-centered control volumes (triangular cells), how can one implement the moving rigid lid boundary conditions for the test case described in Ghia et al. Any suggestions and pointers to papers would be greatly appreciated.

Thanks, Nashat

Boundary conditions must be enforced by proper definition of the boundary flux. If n is the normal and τ is a tangent along the direction of motion of the lid, then u.n=0 and u.τ=U, where U is the specified lid velocity. Some other variables like pressure and stress tensor may have to be interpolated from inside the computational domain. Other possibility is to use normal momentum equation to find the pressure on the wall and then use this pressure to find the boundary flux.

Thanks Praveen.