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Geometry with one reapeating unit

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Hi,

I have a geometry that consists of a geometry unit that repeats one time while both units are connected on one boundary. It's a fluid flow simulation in 3D and I wonder if I can somehow reduce the DOF if I use the periodicity. But unfortunately I cannot apply a real periodic boundary condition since it only repeats one time. For simplification: Imagine a rectangle which I can split into two squares. While they have a common inner edge, where fluid can flow between the two squares, the outer edges are walls. So I don't have a periodicity.

Unfortunately I cannot apply a simple symmetry boundary condition on the inner edge either, since there are some additional elements attached to the repeating unit due to which the whole geometry is not reflection symmetric.

Now, of course I can mesh the complete rectangle. But it would spare me elements and calculation time if I could somehow exploit the one-time-periodicity.

Does anybody has an idea how to make use of the "one-time-periodicity" of a geometry?

Best regards,
Christian

2 Replies Last Post 07.10.2014, 03:59 GMT-4
Jonas Inhestern COMSOL Employee

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Posted: 10 years ago 06.10.2014, 11:45 GMT-4
Dear Christian,

is it possible for you to attach your model? Then I could take a look if there is some kind of simplification possible. Now I can not imagine how there could be some periodicity in your fluid flow simulation, when one of the two elements has some additional elements.

Kind regards,
Jonas
Dear Christian, is it possible for you to attach your model? Then I could take a look if there is some kind of simplification possible. Now I can not imagine how there could be some periodicity in your fluid flow simulation, when one of the two elements has some additional elements. Kind regards, Jonas

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Posted: 10 years ago 07.10.2014, 03:59 GMT-4
Dear Jonas,

thank you for your answer. Meanwhile, I think that it is not possible to simplify it because of the boundary condition of the inner boundary. But maybe I overlook something and you have an idea. I clicked a simple example with a 2D geometry together in order to show you, what I mean.

Best regards,
Christian
Dear Jonas, thank you for your answer. Meanwhile, I think that it is not possible to simplify it because of the boundary condition of the inner boundary. But maybe I overlook something and you have an idea. I clicked a simple example with a 2D geometry together in order to show you, what I mean. Best regards, Christian

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