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Jan Ramboer September 19, 2007 04:35

Opening BC: Normal to boundary
Hello all,

In a calculation, i specify the opening boundary condition because I am having problems with backflow at the outlet. There is an option set "Normal to Boundary" for the velocity direction. Everything converges well, but when I plot the velocity vectors on my outlet surface I notice that they are not at all normal to the boundary. Is this a bug? (using CFX 10).



johnny September 19, 2007 06:42

Re: Opening BC: Normal to boundary
No it's not a bug. On an opening boundary condition, the "Normal to Boundary" part refers to the flow entering the domain only. The flow exiting the domain can be in any direction.

alex September 19, 2007 18:37

Re: Opening BC: Normal to boundary
if u want that velocity vector are normal from your outlet, you could force it by redefining your BC with a velocity profil. bye alex

scrijnczw September 21, 2007 15:06

Re: Opening BC: Normal to boundary
I think forcing the outlet condition will not solve the problem. Better try to extend the outlet geometry longer thus u can avoid backflow at the outlet.

Viele Gruß scrijnczw

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