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Momentum source term problem

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Old   February 10, 2009, 13:00
Default Hi. I have a momentum source
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Ken Darcovich
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Hi. I have a momentum source I need to use (in 2d) that operates with a positive value in the x-direction, but a negative value in the y-direction.

Is there a way to apply source terms to individual components of vectors???

I want to do something along the lines of:
+ fvm::Sp(S,U.component(0)) - fvm::Sp(S,U.component(1))

Any ideas??

thanks,
Ken
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Old   February 10, 2009, 14:53
Default As far as I know its not curre
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Eugene de Villiers
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As far as I know its not currently possible. The diagonal coefficient always has to be a scalar, you are trying to make it a vector.
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Old   February 10, 2009, 16:17
Default One way to do this may be to s
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Ken Darcovich
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One way to do this may be to simply specify Ux and Uy as scalars, and solve them separately with their own different source terms. The U vector can simply be recomposed afterwards for other standard operations.

Any obvious problems (that aren't occurring to me!!) with doing this???

Thanks.
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Old   February 11, 2009, 08:52
Default Well the Laplacian operator th
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Eugene de Villiers
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Well the Laplacian operator that you need for the pressure equation, is not defined for a vector. I am not sure how you would get around this problem. Perhaps use a sparse tensor?

Other than this I don't see anything fundamental, but I'm sure there will be a lot of operational issues that will complicate the problem.

I have a vague recollection that someone else wanted to do this kind of thing a few years back. Have you tried searching the forum?
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