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UDM (user-defined memory) boundary condition?

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Old   September 30, 2010, 13:03
Default UDM (user-defined memory) boundary condition?
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I've written a k-w-v2-f turbulence model, where epsilon is stored as a user-defined memory term. I need to set the boundary condition for epsilon at an inlet.

Does anyone know how to set a boundary condition for user-defined memory terms?
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Old   October 1, 2010, 05:04
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I also have similar prob for uds bc..expecting
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Old   October 1, 2010, 10:04
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Do you mean UDM BCs? UDS BCs are simple, I can help you with that if you'd like.
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Old   October 1, 2010, 13:17
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Quote:
Originally Posted by tstorm View Post
Do you mean UDM BCs? UDS BCs are simple, I can help you with that if you'd like.
Thanks a lot!

For specified flux at outlet (pressure outlet)

I am wondering what does specified flux means exactly?

and there is one part (even i choose specified flux), i need to fill in the specified value, for one thing it is difficult to know; another thing, I put roughly guessing value there. it turned out 0 and 1 , there is not influence for the result at all.

could u give me some hint? thanks!
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Old   October 1, 2010, 13:36
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The flux is the rate of flow. A specified flux of 0 for a UDS at a wall, for example, would mean that there's no change in the UDS value between the wall and the first cell above the wall. I generally use a specified flux of 0 when I don't know the boundary condition - like at an inlet or outlet.
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Old   October 1, 2010, 14:44
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Thank you a lot! that is very clear
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