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flow through a periodic array of posts

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Hi,

I want to explore the flow of fluid through a periodic array of posts. The array is tilted with regard to the flow direction. I aim to do this by using a unit cell and periodic boundary conditions. I have two questions:
1. which boundary conditions will allow me to make the flow truly periodic but also allow me to control pressure differences across the unit cell. Will i have to map the flow out of my unit cell back into it and if so how is this done?
2. while the array i want to model is large, it is not infinite. The walls in my real device force the flow to move parallel with them. In the periodic model this doesn't occur and the flow changes direction according to the rotation of the array. I have heard that the flow direction in the model can be controlled using a stream function that forces flow lines through defined points in order to simulate distant walls but i have no idea how to set this up. Any pointers?

Thanks for any help!

1 Reply Last Post 19.10.2010, 05:21 GMT-4

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Posted: 1 decade ago 19.10.2010, 05:21 GMT-4
it turns out that by making sure the Physics Model is set to incompressible flow then the option to set a pressure difference across the periodic boundaries appears in the periodic boundary condition settings. Great! But it would still be good to get some advice on how to use a stream function.
it turns out that by making sure the Physics Model is set to incompressible flow then the option to set a pressure difference across the periodic boundaries appears in the periodic boundary condition settings. Great! But it would still be good to get some advice on how to use a stream function.

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