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Boundary condition again

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Old   November 26, 2005, 10:07
Default Hi, everyone. I have some q
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Efimenko Evgenii
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Hi, everyone.

I have some questions about boundary conditions.
1.Is it possible in boundary condition specify only 2 vector components? I mean, for example, E.x=0, E.y=0, E.z - has arbitrary value(there is no any conditions)
2. If I don't have any conditions can I write "calculated"? I've tried, but it didn't work. It returns error.
3. Can I specify boundary conditions in solver code?

Thank you
Eugene
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Old   November 26, 2005, 10:40
Default 1 The (x y z) decomposition do
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Hrvoje Jasak
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1 The (x y z) decomposition does not make sense to me - you probably mean "normal to the boundary" and "tangential to it" when you think about it a bit more. There is a directionMidex b.c. and a more general form which allows you to have a separate mixed b.c. on each component (normal and tangential)

2 "Don't have any conditions" in the FVM probably means zeroGradient. Try that. "calculated" is for special cases, where the code genuinely does not know the b.c., e.g. when it's doing fv calculus: consider the b.c. on div(U) :-)

3. Yes and no. If you build teh field completely in the code, you can give it a list of b.c.-s, but hooking them up and setting parameters in most cases requires casting. If you read the field from a file, and you know what the b.c. is, you can cast it in the code and mess about with it.

Enjoy,

Hrv
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Old   November 26, 2005, 11:04
Default Yes, I really mean that tangen
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Efimenko Evgenii
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Yes, I really mean that tangential component is equal 0, and normal component doesn't have any conditions.

Yes, probably "zeroGradient" is something I need.

Thanks a lot, it's very useful fo me
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