CFD Online Discussion Forums

Useful article about mesh types

Posted September 23, 2013 at 02:08 by skeptik (CFD notes)

Polyhedral, Tetrahedral, and Hexahedral Mesh Comparison

http://www.symscape.com/polyhedral-t...esh-comparison

skeptik

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NACA23012 numerical modelling, wing body in tube

Posted September 19, 2013 at 08:42 by skeptik (CFD notes)

Result line fit really good.
And it's much more better than 2D calculations of the same airfoil

Cx, Cy

Click image for larger version

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Residuals

2D results
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OpenFOAM: Interesting cases of bad meshes and bad initial conditions

Posted September 15, 2013 at 07:03 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...

wyldckat

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Posted in Links and tutorials for OpenFOAM and dependencies

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Wave Action Equation Solver for OpenFOAM

Posted September 3, 2013 at 08:18 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...

egp

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second order schemes

Posted August 28, 2013 at 11:43 by skeptik (CFD notes)

Quote:

Originally Posted by alberto

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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