implementation boundary condition for non-orthogonal mesh
 

hi everybody
I am writing a code that solves diffusion for non-orthogonal mesh and I don't know how could I insert boundary condition
I mean for example for 2D orthogonal system we have:

ap*phip=de*phie+dw*phiw+dn*phin+ds*phis+su

but in non-orthogonal system some terms will be added to source term, that is we will have:

ap*phip = deksi*phie+dwksi*phiw+dneta*phin+dseta*phis+deeta( phine-phise)-dweta(phinw-phisw)+dnksi(phine-phinw)-dsksi(phise-phisw)+su

and it is simiplified to :

ap*phip=deksi*phie+dwksi*phiw+dneta*phin+dseta*phi s+su

in which ;
su=su+deeta(phine-phise)-dweta(phinw-phisw)+dnksi(phine-phinw)-dsksi(phise-phisw)

NOW I DON'T KNOW HOW SHOULD I INSERT BOUNDARY CONDITION TYPE I AND TYPE II FOR THIS SYSTEM:confused:

THANKS EVERYBODY

look into cfd wiki and how diffusion term is descretized. Work the same way.