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Solving Geometry Piecewise.
Posted 28 mai 2012, 05:18 UTC−4 Fluid & Heat, Computational Fluid Dynamics (CFD), Geometry, Studies & Solvers Version 4.2a 3 Replies
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I am having some problems with RAM limitations and so I have to split my geometry in pieces so I can handle it a lit bit better.
My geometry is quite simple, but the mesh requirements made it necessary to split the geometry.
At first I tried to import the results from each section but I keep getting the same error, in spite of refining my mesh...
"Segregated group 2
Attempt to evaluate negative power of zero.
- Function: ^"
So, I though about breaking the geometry into pieces and using the periodic flow BC or the flow Continuity BC,
and setting up the solver to solve each piece at a time.
However I am struggling a bit to implement the solver (see attached file). It only solves for the first section.
Is this possible to implement? Anf if so, can anyone provide insight into my mistake in the solver.
Thank your in advance.
Best Regards,
Rui Silva
Attachments:
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I do not undersand what you try to do here ;) you need to explain a bit more.
What I can anyhow say: you have NO CHANCES to get a turblent flow solving if you do not use an appropriate mesh, the default physics induced mesh is rather adequate with boundary layers etc
you are in 2D and not 2D-axi so I understand this as a flow between two plates of typically 1[m] depth (depth = Z = out of plane direction), do we agree (it remains a first approach to a pipe flow thow).
I do not understand the periodic condition linking in the two geometries
If your problem is that the pipe is looong, well what changes over the length, for me the turbulent flow needs some distance to develop, then it will not really change a lot, (OK if you heat it up things will change) bt if you model a first 1[m] then you could get a first approximation for the response "per meter" and you could start using this as a linear estmator for a longer length
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Good luck
Ivar
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this case that I have uploaded is just a test for what I'm trying to achieve.
The real mode is much more heavier and the mesh is really dense, which makes the upload impossible.
You are correct in your assumptions, but I really need to model a 1.5 meter entrance length pipe.
But since the mesh is so dense, the RAM that I have is not enough so I'm trying to split the geometry and solve it piecewise (if this is possible I do not know).
So I went into 2 different directions:
1) to solve part of the geometry and import those results into another file with the remaining geometry. But i got the error I mentioned in my previous post.
2) to solve the geometry piecewise (in the same file) through the manipulation of the solver and either using the "Periodic Flow Condition" or "Flow Continuity Condition". I used to different mesh for each part of the geometry, but the solver only resolves for the first part. And I get a warning stating that the mesh in part 2 does not exist.
Hope I was clearer this time around.
Thank you for your reply.
Rui
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for uploads its better to clear the mesh and the solution, then the file is much smaller and each user can rerun the model.
Splitting up a model istricky, but indeed possible, isung symmetry is one way, decoupling the physics another
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Good luck
Ivar