[Gmsh] Problem meshing a sphere. gmsh crash meshing or not recognize the volume.

Esteban Vargas vb.esteban at gmail.com
Wed Sep 24 06:32:43 CEST 2014


Thanks hugo.

That works nice and finally can get the mesh.

But, how do I proceed to get the volume of the sphere with no mesh? It's
possible?

2014-09-23 8:00 GMT-05:00 Hugo Fernando Maia Milan <
hugomaiamilan at hotmail.com>:

> Hi,
>
> It looks that the size of the point that you defined are very small
> compared to the size of the object. I had created a new file, check it in
> the attached.
>
> In this file, you can specify the radius of the sphere and the lengths of
> the rectangle. Pay attention in the size of the points because they are
> critical in regard of the size of your elements (and the mesh,
> consequently).
>
> If it is too slow or you can't create the mesh, just increase the values
> of lc and lesfera in the file.
>
> Hugo.
>
> ------------------------------
> Date: Mon, 22 Sep 2014 10:28:20 -0500
> From: vb.esteban at gmail.com
> To: gmsh-request at geuz.org; gmsh at geuz.org
> Subject: [Gmsh] Problem meshing a sphere. gmsh crash meshing or not
> recognize the volume.
>
>
> Hi.
>
> I'm a new user of gmsh, I have developed some tutorials in it, but now i
> have several problemas.
>
> I'm trying to simulate the flow around a sphere, the main goal is
> calculate the drag force and drag coefficient in OpenFOAM. However, I'm
> having a lot of problems creating the mesh, I've made two process to
> generate the mesh with no success at all.
>
> First way.
> 1. I generate a CAD model in solidEDGE, in that model I draw a solid
> volume with the hole of the sphere (boolean operation). The volume
> represent the all fluid.
> 2. I export the CAD Model into step, stl and igs files.
> 3. In gmsh, merge the step model.
> 4. gmsh show the surfaces, points and volumes rigth (gmsh show the walls
> in gray solid color).
> 5. Define the physical groups, surfaces with no problem.
> 6. When I try to select the volume in physical group is just impossible.
>
> Second Way
> As the geometry is a bit simple, I decided to draw the sphere and the box
> in which its embeded in gmsh.
>
> 1. I draw some points to define the sphere.
> 2. Create circle arc to define the sphere.
> 3. With those circle arcs created I defined ruled surface in the sphere.
> 4. Then Create the box around the sphere.
> 5. The surfaces in physical groups are defined normally, but I created a
> surface call sphere, in which I select the all ruled surfaces created on
> the sphere.
> 6. Select the volume in the physical groups (WHEN I DEFINED THE PHYSICAL
> GROUPS I'VE ALREADY DEFINED THE VOLUME AND SURFACES IN ELEMENTARY ENTITIES)
> 7. Then, with everything O.K. I try to create the mesh, but the program
> just crash, and close.
>
> I have a problem to open gmsh to, everytime I try to open it I have to
> write in the console (Ubuntu) this: gmsh primary.geo -tol 1e-9
>
> I attach the geo file.
>
> Thanks! I really appreciate any comment about it.
>
> spheredesarrollada.geo is the second way file generated.
> sphereNueva.geo is the first way file
> --
> Esteban Vargas Bolívar
> Metálicas Léguz S.A.
> Tel.: (4)5203600 Ext. 103
>
> _______________________________________________ gmsh mailing list
> gmsh at geuz.org http://www.geuz.org/mailman/listinfo/gmsh
>



-- 
Esteban Vargas Bolívar
Metálicas Léguz S.A.
Tel.: (4)5203600 Ext. 103
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