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[blockMesh] what does this syntax mean?

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Old   July 2, 2021, 00:48
Default what does this syntax mean?
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qutadah
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Hallo, im pretty new to openFoam and when doing the tutorial of incompressible steady turbulent flow over a backward-facing step, the following syntax in the BlockMeshDict comes up. Can someone explain how to understand this?


This is the code:


hex (0 3 4 1 11 14 15 12)
69 (18 30 1)
70 simpleGrading (0.5 $posY 1)
71
72 hex (2 5 6 3 13 16 17 14)
73 (180 27 1)
74 edgeGrading (4 4 4 4 $negY 1 1 $negY 1 1 1 1)




what do the $negY and $posY mean? Thanks!
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Old   July 2, 2021, 02:21
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These are variables declared somewhere else, probably within the blockMeshDict itself (at the top?), or, maybe in another file in your case. In the latter case, then this file would be included in the blockMeshDict at the top by an include statement.
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Old   July 2, 2021, 11:10
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Hello, yes they are defined in my file, but what do they represent? this is only mentioned in the grading... thanks


negY
(
(2 4 1)
(1 3 0.3)
);

posY
(
(1 4 2)
(2 3 4)
(2 4 0.25)
);

posYR
(
(2 1 1)
(1 1 0.25)
);
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Old   July 2, 2021, 11:21
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Quote:
Originally Posted by AtoHM View Post
These are variables declared somewhere else, probably within the blockMeshDict itself (at the top?), or, maybe in another file in your case. In the latter case, then this file would be included in the blockMeshDict at the top by an include statement.

plus i have noticed the hex block vertices are defined weirdly, (not like previous examples... even looking at the mesh I am not able to follow which block is which... and there are no 3d vertices)


blocks
(
hex (0 3 4 1 11 14 15 12)
(18 30 1)




any idea how is this exactly defined? thanks
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