ANSA hexblock mesh to OpenFOAM
 

Dear everybody,

i have been working these days with ANSA meshing the pipe tutorial (hexablock meshing, pipe junction) with the new hexblock feature.

I have associated the hexboxes to the geometry and meshed it correctly. I setup the boundary conditions and the solver, etc. in ANSA and export it to OpenFOAM files, then I simulate the case.

the problem seems that the boundary conditions specified in ANSA are not applied in the cells and the solver gives always errors of 0 and 0 number of iteration in all parameters. I think there is a step that I haven't done in the process of exporting or i have to specify something more in ANSA (ANSA tutorials doesn't says anything, the other tutorial of the pipe bend "case setup and morthing for OpenFOAM" it works just fine because i think the mesh is created within the surfaces of the geometry and b.c. are applied to these surfaces).

kind regards

yosuu

dear yosuu

after you create the hexa mesh and are satisfied with the result, you should use the VOLSKIN function of the hexablock menu.
this will generate new quad elementsaround the volumes.
these elements will take the same pid as that of the original geometry, so they will have the proper bc's
finally when you output make sure you have Macros visibility off, so that you do not output any meshed geometry, but have Vokume and FE-mod mesh ON so that you output the hexas and quads respectively.
hope this helps

Regards
Vangelis

thank you vangelis!

it worked perfectly.

you are very welcome!
v

Hi vangelis,

I wanted to ask you if you know any way to define the boundary layer in the hexblock mesh. I found one but it's quite manual: first i have the hexblock, then I use the o-grid function. to create the boundary layer i split in one of the new edges i have created. I attach a image here.

Hi Yusuu

as you understand O-GRID function is supposed to create the boundary layers, but indeed the layer height is not so well respected (layers get
more inflated inwards).
I assume you have ended up with this workaround to ensure this.

What I would recommend is that you download the new version
v13.2.0
In this version the OGRID function generates layers with accurate
height values.

Regards
Vangelis

Hi Vangelis,

thanks for the tip. In the company, we are currently using the v13.1.3; I'll try to speak to my boss and think about upgrading to v13.2.0. I really appreciate all your help :)!

kind regards,

Yosuu

Hi Yosuu,

Indeed there are several improvements in v13.2.0 for Hexablock
with respect to O-Grid generation and accuracy in mesh generation.
I would recommend that you tried it.

Best regards

Vangelis