How to calculate the divergence on the boundary?
 

Hi,I am discretizing the N-S equtation on a co-located no-orthogonal grid with finite volume method. I meet a problem when I deal with the source term of momentum equation. There is a partial derivative calculation for divergence term ( <Partial(div(U))/Partial(x)>in the source term. As we all know a node locates on the boundary with the volume equal zero, and there is also no definition for the node on the corner formed by two boundaries. How to discretize it, and is the divergence on the boundary equal zero? thanks!! maximus

Re: How to calculate the divergence on the boundar
 

maximus,

I am not quite sure I understand your question.

Usually the divergence term is manipulated in the FVM by the divergence theorem to yield surface integrals on the control volume (cell) faces. On the other hand, on boundaries you should apply (discretized) BC, e.g. Dirichlet- or Neumann- type, rather than the conservation equation, and hence there is no divergence term there.

I hope this helps.