Dear Praveen, Unfortunately there are no characteristic boundary conditions implemented (We have never really used cgcns very much for external aerodynamic flows). If you enclose your airfoil in a big rectangle (or multiple rectangles) then you may be able to use the existing BC's Regards, Bill Praveen C wrote:
Thanks. I now understand this a little better and able to do some computations. Are there any characteristic-based boundary conditions available in cgcns ? What type of BC would I use for compressible flow for a curved outer (farfield) boundary. I may not know the direction of the velocity there since the boundary is curved.Thanks praveen praveenOn Wed, Jul 15, 2009 at 9:05 AM, Bill Henshaw <henshaw@xxxxxxxx <mailto:henshaw@xxxxxxxx>> wrote:Dear Praveen, Sorry, that error message is not very good. Try using backGround(1,0)=subSonicOutflow mixedDerivative(1.*t+1.*t.n=300.) as in cg/cns/cmd/cicSubSonic.cmd Regards, Bill