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scale factor By simon

Posted January 6, 2013 at 19:17 by diamondx

Scale factor lets you adjust all the sizes in the model at once...

By default, you should probably leave it as 1, which means that all the other sizes could be taken at face value.

Then if you want to make the model 20% coarser, you can come back and set the scale factor as 1.2. Get it?

Scale Factor times Max Element size gives you the largest element in your model. For Octree, this is the size of the initial subdivision when Octree is first initialized....
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Hexadominant method...

Posted December 20, 2012 at 11:42 by diamondx

I agree with "Far", but don't recommend the Hexadominant method for CFD.

The Hexadominant method starts by paving quads at the walls and then marches inward with isotropic hexas which can crash somewhat badly in the middle. This is good for FEA structural analysis where most of the interesting stuff happens near the surface and uniform elements are sufficient to capture it all, but it is not good for CFD.

However, if you tried Multizone (or sweep) with...
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Animation of Fluent transient data

Posted December 17, 2012 at 12:23 by diamondx

Actually CFD Post does support FLUENT transient files, but you should open a dat file that uses the FLUENT transient naming conventions, that is, filename-XXXXX.dat, where XXXXX is the timestep number. Your cas file should be named filename.cas (without the timestep number). If you have other cas files with the timestep number, try moving them to another folder.

I use it here a lot and it works fine.

Cheers.

By BRUNOC
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improving quality after merging tetra and prism

Posted December 1, 2012 at 10:19 by diamondx

you can only merge meshes if one side is all tetra... It needs the flexibility of the tetra mesh make it work. Prisms are too restrictive. We are working on ways to improve this situation.

Prism quality looks worse than it is... No worries there either.

As for the poor tetras, run the smoother with the prisms and hexas frozen... see what it can do. It should fix most tetras. The tetras it can't fix are those that are stuck between close layers of prisms... ...
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Mesh quality criteria in ICEM

Posted November 23, 2012 at 10:18 by diamondx

First of all these values are relative. There are many values which are not acceptable to Fluent but CFX. For example fluent is more tolerant of angle issue than the CFX. But Fluent does not like the pyramid shape and CFX does not mind it because of its internal working.

Keeping in view they have (meshing guys) have devised some metrices with factor of safety. Following are the most important quality metrics with thier range.

Angle : Must be greater than 18 deg (But...
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