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Free-slip boundary condition

Jose Antonio Castillo Torres

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i'm simulating a open water channel. I don't know, what are the options for implement the free-slip condition in the upper part of the water channel?

1 Reply Last Post 5 nov. 2012, 16:44 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 5 nov. 2012, 16:44 UTC−5
Hi

if you check the equations, Wall "slip" and symmetry are the same, but they "block" the surface flow normal direction, nothing is crossing the boundary, else you need an open boundary.
Now open boundary and outlet no visous stress are the same (check the equations). But often its usefull to set a gauge pressure somewhere, therefore the outlet pressure no viscous stress seems adequate for me, if I have understood correctly your short model description

--
Good luck
Ivar
Hi if you check the equations, Wall "slip" and symmetry are the same, but they "block" the surface flow normal direction, nothing is crossing the boundary, else you need an open boundary. Now open boundary and outlet no visous stress are the same (check the equations). But often its usefull to set a gauge pressure somewhere, therefore the outlet pressure no viscous stress seems adequate for me, if I have understood correctly your short model description -- Good luck Ivar

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