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Courant Number Cell Size

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Old   June 3, 2016, 10:41
Default Courant Number Cell Size
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vitor gabriel silva
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Dears,

I have some questions about Courant number.



Example of solver IcoFoam:




This 0.5 for “endTime”. Did it do the calculation by the lenght of the geometry and the velocity of the flow? Just made a guess how long is it necessary to flow around all the geometry?


The Courant number must to be less than 1 for 1 cell (for this case). He put the worst case Co =1. Ok.

So he jumps to the “dx” that is the “deltaT”. Ok


But now the calculate the “dx” by the cell size “d” per “n”. I don’t know where did it take the cell size and what is it the “n”. From where did he take “d=1” and “n=20”? I looked the “checkMesh” and this extension for OpenFOAM.

http://openfoamwiki.net/index.php/Sc...g_calculation)


This “r” ratio between one cell size and the next is cell-to-cell expansion ratio? Where can I have this information when I’m not using blockMesh. I know in blockMesh have to see in simpleGrading or edgeGrading.


Although I’m using SolidWorks and Ansys to do the Geometry and Mesh, and after I change by fluent3DMeshToFoam. I tried “checkMesh” but there are


“Minimum face area = 0.00336069. Maximum face area = 0.140432. Face area magnitudes OK.”


Is this “face are” the face of the cell?




Thank you very much.
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