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OpenFOAM: Interesting cases of bad meshes and bad initial conditions

Posted September 15, 2013 at 06:03 by wyldckat

This year (2013) has been an interesting one for me, regarding OpenFOAM. Even beyond the amazing features that OpenFOAM 2.2 brought to the world (at least to my world) and everything that I keep discovering about it.

This blog post is about the various threads/posts were I took the time to diagnose what was specifically wrong with the case and where the bad results are astonishingly wrong... simply because the details were not easily seen. The list might get updated along time, as I...
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Wave Action Equation Solver for OpenFOAM

Posted September 3, 2013 at 07:18 by egp

Hi Tom,

This sounds like an interesting problem! Ignoring the wave space issue for a moment, I think you need to first cast the problem as a 2D surface using either the finiteArea machinery of 1.6-ext, or the thin film model in 2.2.x (see reactingParcelFilmFoam).

The wave space issue is a bit more complex and I don't have a good recommendation for an elegant solution. Brute force for a fixed number of wave-space bins would be doable, but ugly. What is the typical...
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second order schemes

Posted August 28, 2013 at 10:43 by skeptik (CFD notes)

Quote:
Originally Posted by alberto View Post
Hi,

both limitedLinear and linearUpwind are bounded. What is different is how the boundness of the scheme is obtained (see table 4.10 of User's guide).
  • limitedLinear is the linear scheme stabilized with the introduction of a limiter (Sweby limiter)
  • linearUpwind in an upwinded scheme
About their accuracy, limitedLinear is in my experience slightly less diffusive, but I had good results with both the schemes.

I believe the second order upwind scheme in commercial
...
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A few simple questions about linearUpwind and limitedLinear

Posted August 28, 2013 at 10:36 by skeptik (CFD notes)

Quote:
Originally Posted by chegdan View Post
I am a writing about the schemes that I used in my simulations in my thesis and could use some clarification on the linearUpwind and limitedLinear schemes. I have read http://www.cfd-online.com/Forums/ope...r-schemes.html and Alberto did a good explanation, but I need a little more clarification.

linearUpwind:

I know linearUpwind is second order and bounded by a limiter (e.g. cellMDLimited from http://www.cfd-online.com/Forums/ope...lllimited.html).
...
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Mesh OK!

Posted August 23, 2013 at 03:53 by skeptik (CFD notes)

13e6 elements with SALOME (4 core CPU, 8Gb, Linux)

10e6 - tetra,
3e6 - prism layers.

Meshing time is about 2 hours.

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