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#1 |
Member
Guifan Li
Join Date: Apr 2011
Location: New York City, U.S.
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Hi everyone,
I am simulation the blood flow in the bifurcation( I used Gmsh to mesh the bifurcation and import it to Openfoam). When I icoFoam it, the courant number always explode at the intesecation which you can view it one the picutures below. It seems like the velocity is reflected by the sharp corner and pierce the wall then cause it explode. I am quite new to Openfoam and not sure whether it is because my mesh or because of other reasons. Can anyone point out what's going wrong? Screenshot.jpg Screenshot.jpg Screenshot-1.jpg |
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#2 |
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Guifan Li
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p file
dimensions [0 2 -2 0 0 0 0]; internalField uniform 0; boundaryField { wall { type zeroGradient; } inlet { type zeroGradient; } bent_outlet { type fixedValue; value uniform 0; } straight_outlet { type fixedValue; value uniform 0; } } U file dimensions [0 1 -1 0 0 0 0]; internalField uniform (0 0 0); boundaryField { wall { type fixedValue; value uniform (0 0 0); } inlet { type fixedValue; value uniform (0 0 0.05); } bent_outlet { type zeroGradient; } straight_outlet { type zeroGradient; } } Last edited by liguifan; June 28, 2011 at 05:43. |
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#3 |
Senior Member
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Can you check whether there's any "funny" cell in that region?
I would open the mesh in paraview (or whichever software you prefer) and do some slices... |
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#4 | |
Member
Guifan Li
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Quote:
Thanks for replying my post. I tried to use paraview to slice it. First of all , there is no hole in that region and I didn't find any wired cells in that region. Could other reasons lead to explode? |
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#5 |
Senior Member
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Can you please post a picture of that region? just the mesh.
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#6 | |
Member
Guifan Li
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Picture 4.jpg
Screenshot-3.png Screenshot-4.png Picture 2.jpg Picture 3.jpg Screenshot-4.png Quote:
Here are some pictures of the mesh, please let me know if you need more. thanks |
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#7 |
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Guifan Li
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Screenshot-5.png
and this thanks |
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#8 |
Senior Member
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Could you please post a slice of the region where you're having the blown up?
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#9 |
Member
Guifan Li
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Screenshot-6.png
Screenshot-7.png Screenshot-8.png Screenshot-9.jpg Hi lore, It is quite hard to slice the exact point where it blow up, but here are some mesh slice that is the blow up region. hope it helps . If you want, I can send you my file which is too large to upload here. Cheers |
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#10 |
Senior Member
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Guifan, you should slice the pipe with a zx plane, ie a plane wich lies in the flow direction.
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#11 |
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Guifan Li
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#12 |
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Mmm, your mesh seems to be ok...Maybe you should wait for somone with more experience than me...
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#13 |
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Guifan Li
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lore, thanks for that anyway
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#14 |
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Have you tried changing the time step?
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#15 |
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Guifan Li
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#16 |
Senior Member
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Yes, that's what I meant: in both cases you changed the Courant number. I only mentioned the time step and not the cell size because I thought you wanted to keep the mesh the same.
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