[immortality]

Hi Bruno
I need it on OF 2.2.0

[akidess]

Originally Posted by immortality

Hi Bruno
I need it on OF 2.2.0

Ehsan, go ahead and try the code and see if it works. There is a good chance no changes are required.

[immortality]

OK.thanks.compiled without error.
but in conventional way we have for example:

hex (0 1 4 3 9 10 13 12) (400 40 1) simpleGrading (2 4 1)

in (2 4 1) each number is related to (positive x-direction,y-direction,z-direction)
and its clear.
but in simpleGrading how it is implemented?
I expected something like: ((1 2 3)(4 5 6)(7 8 9)) for double grading,could anyone enlighten me?

hex (0 1 2 3 4 5 6 7) (20 10 20) simpleGrading (-5 1 1)

[wyldckat]

Greetings to all!

@Anton:

Originally Posted by akidess

Bruno, did you ever test it on 2.2? If so, we could add the 2.2 template to the wiki...

Nope, I only had time to build it and to fix the zip related instructions. I'll try to give it a spin tomorrow, using the case from post #25.

@Ehsan: Check the wiki: http://openfoamwiki.net/index.php/Co...ckMeshDG#Usage - and check the examples shown in this thread you're reading.

Best regards,
Bruno

[greenleader]

Originally Posted by akidess

Bruno, did you ever test it on 2.2? If so, we could add the 2.2 template to the wiki...

I've used it with OF v2.2.0 - no issues with it - it just works!

[immortality]

its only this:

For example, simpleGrading (1 -2 1) in blockMeshDict means the created mesh has cells two times larger in the center than those at the side.

which side we are talking about in grading?if its a 3D mesh it means it has less cells in the middle of domain but we want both sided grading in each face of domain.
what we can do when we want different grading in different directions?it seems nothing!
although this work is valuable but has some defects in it.

[wyldckat]

Greetings to all!

@Steve: Many thanks for the report!
@Anton: Wiki page updated.

@Ehsan:

Originally Posted by immortality

which side we are talking about in grading?if its a 3D mesh it means it has less cells in the middle of domain but we want both sided grading in each face of domain.

"simpleGrading (1 -2 1)" - The minus 2 is for the Y direction.

You might not see much with just "(1 -2 1)", because it's just an example; it implies that the person reading the instructions already has some experience with blockMesh's original grading capabilities, which are explained in the OpenFOAM User Guide, section "5.3 Mesh generation with the blockMesh utility", more specifically subsection "5.3.1.3 The blocks": http://www.openfoam.org/docs/user/blockMesh.php

Best regards,
Bruno

[immortality]

thanks.so it only do double grading.if someone likes single grading in x-direction as well as double grading in y-direction can combine blockMesh and blockMeshDG together?I still think we need a more powerful tool in meshing.
------------------------------------------------------
I tested it by a very coarse mesh:

hex (0 1 2 3 4 5 6 7) (10 8 1) simpleGrading (-2 -4 1)

and works fine as the attachment.it made me free of so many excess points and blocks!

[GerhardHolzinger]

Hello,

I noticed a problem when using double grading and an uneven number of cells.

[akidess]

Please attach your blockMeshDict.

Originally Posted by GerhardHolzinger

Hello,

I noticed a problem when using double grading and an uneven number of cells.

[GerhardHolzinger]

Here is my blockMeshDict.

[akidess]

Gerhard, I think your edgeGrading is botched. Double check while referring to figure 5.5 of the user manual for the edge numbering.

Edit: I take that back for now Need to look into this a bit more carefully.

[greenleader]

Yes, I seem to recall that doublegrading does not work with an odd number of cells. I always make sure I use an even number.

[kingmaker]

Hello

Do any one know if this utility works with edge grading also.. ?
Like if we say one of the values in edge grading to be -ve ... will that edge be graded on both sides .. ??

Thank you

[akidess]

I think Gerhard had success using edge grading. Just be sure to specify an even number of cells.

[kingmaker]

Originally Posted by akidess

I think Gerhard had success using edge grading. Just be sure to specify an even number of cells.

Hello Thank you for your answer. I will try and post if I have any problems.
Mean while, I have one more question, can we use snappy hex mesh after blockMeshDG with out any problems ... ??

Thank you

[roamer]

Hello Everyone,

Thanks for sharing. But for some meshes using this "double grading" create high aspect ratio meshes and non-orthogonal faces.
I found that a minor editing to the file curvedEdges/lineDivide.C solves the problem.

        if ( xratio > 0 )
        {
        for (label i=1; i < ndiv; i++)
        {
            divisions_[i] = (1.0 - pow(xratio, i))/(1.0 - pow(xratio, ndiv));
        }
        }
        else
        {
            for (label i=1; i < ndiv; i++)
            {
                if ( i <= ndiv/2.0 )
                {
                    divisions_[i] = (1.0 - pow(-xratio, i))/(1.0 - pow(-xratio, ndiv/2))/2;
                }
                else
                {
                    divisions_[i] = 1.0-(1.0 - pow(-xratio, ndiv-i))/(1.0 - pow(-xratio, ndiv/2))/2;
                }
            }
        }

To this:

        if ( xratio > 0 )
        {
        for (label i=1; i < ndiv; i++)
        {
            divisions_[i] = (1.0 - pow(xratio, i))/(1.0 - pow(xratio, ndiv));
        }
        }
        else
        {
            for (label i=1; i < ndiv; i++)
            {
                if ( i <= ndiv/2.0 )
                {
                    divisions_[i] = (1.0 - pow(-xratio, i))/(1.0 - pow(-xratio,ndiv/2.0))/2.0;
                }
                else
                {
                    divisions_[i] = 1.0-(1.0 - pow(-xratio, ndiv-i))/(1.0 - pow(-xratio, ndiv/2.0))/2.0;
                }
            }
        }

I hope it helps somebody.

[akidess]

I pushed your patch to the repository: http://code.google.com/p/blockmeshdg...a63253d80a5c93

If you would like to be acknowledged differently please let me know.

[immortality]

Hi Anton
I can't have access to this link by this message "Request not allowed from your country That’s all we know."could you upload it anywhere else?
thanks.

[akidess]

Sorry Ehsan, but I do not have the time to repackage and re-upload every commit. The code changes however are minimal and are within this thread, so you could easily make your own executable.