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2D buoyantBoussinesqSimpleFoam weird solution

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Old   August 29, 2016, 08:06
Default 2D buoyantBoussinesqSimpleFoam weird solution
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Hi,
Currently I am trying to simulate a simple HVAC case, an inlet in a room, vith 6 K deltaT. I used Pimple and simple solvers, but the problem is the same.
I have two models, a 3D model and a 2D simplification.
The 3D case works well, the solution is logical, as you can see in the first image (slice of the symmetry plane of the room,U magnitude). But, when I use the 2D case it isnīt (second image). I thought that adding more iterations was the solution but still have the same problem after 200.000 iterations.
If anyone knows the solution, please tell me.
Best regards,
Daniel
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File Type: png DD_PAT_200_color.png (26.4 KB, 9 views)

Last edited by danielbanos10; August 31, 2016 at 07:13.
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Old   October 3, 2016, 10:45
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One of the solutions I found is using 3D with few cells in "y" direction and setting symmetryPlane BC.(pic attached).
Anyone had a similar problem ?
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Old   October 4, 2016, 01:50
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It looks to as if your solution is not converged yet. Lower your tolerance in fvSolution and remove the relaxation in the temperature field. (h/e). Or raise them to 0.9 or something similar.
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Old   October 4, 2016, 02:00
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Quote:
It looks to as if your solution is not converged yet. Lower your tolerance in fvSolution and remove the relaxation in the temperature field. (h/e). Or raise them to 0.9 or something similar.
Yes, that's was my first thought (reffering to the first post), so I changed the tolerance, did 200000 iterations, modified the relaxation of T to 0.8. And nothing changed... (in 2D case)
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