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pisoFOAM - internal pipe flow - convergence

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Old   December 18, 2017, 13:12
Default pisoFOAM - internal pipe flow - convergence
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gu1
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Hello,

First, I'm using OpenFOAM 5.0 (komegaSST), the mesh is attached below as well as the link to Dropbox, where you can see all my settings.

Re = 5300 (R = 0,006035 - L=5D)
DROPBOX

I believe my settings are ''good'', but they can improve and I need your help for this.
Inside the file there are two images related to RESIDUAL. With a shorter timeStep I was able to converge faster, but to certain extent (300 iterations), then tend to behave steadily ... I would like to improve performance, because according to bibliographical references it was possible the convergence with 1200 iterations (if not verified in my configurations).

And a question that arises is with respect to the Courant number, for deltaT = 1e-4 the value is around 0.1, while for deltaT-1e-6 this value drops significantly (Co = 0.01). Would it be necessary to have such a low Co to accelerate convergence?

Quote:
yPlus yPlus write:
writing object yPlus
patch pipe y+ : min = 0.0264039, max = 0.0322391, average = 0.0302202
For this reason (y + ~ 1) and according Tobi, I set my settings:

Quote:
-boundary conditions for walls:
U=(0,0,0), p=zeroGradient, k=1e-15, omega=omegaWallFunction, nut=calculated
to eliminate the wall conditions. Did I execute correctly?

... and, according to my settings, I set the internal velocity to be 1 m/s (because it is a cyclic domain, there is a need for a fvOption file). This velocity was not constant throughout the iterations, reducing it. This is normal?

Thanks
Attached Images
File Type: jpg mesh.jpg (105.2 KB, 14 views)

Last edited by gu1; December 20, 2017 at 13:12.
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komegasst, openfoam, pisofoam, wallfunction

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