[Gmsh] mesh refinement according to orography slope

[Tumolo Giovanni]

 Dear all,

 thank you so much for your quick help,

 we've followed the tutorial steps. Using the .pos file from the tutorial
 you suggested we were able to get a mesh refined as expected.

 Then we've tried to create different .pos files (see attachments) closer
 to our needs.

 For example, distance.pos sets the distance from the boundaries as the
 field (the domain is the same as t1.geo). However, the mesh we get does
 not look good because it has some strongly distorted elements (very long
 in one direction) in a region (close to the right vertical boundary) where
 we would expect a refinement.

 In addition, in file distance_inv.pos we calculated the inverse of the
 previous field as 1 / (distance_val + 0.01) limiting to 60.0 the values
 too high. In this case, after merging the .pos file, and
 setting it as background mesh, the obtained mesh is even uniform.

 Can you detect errors in the attached .pos files?

 We cannot understand why the mesh is not refined where the background
 field assumes small values.

 Thank you a lot for your help!

 Best,

 Giovanni e Stella

>
>
>>> With this target in mind we are looking for a method to refine the mesh
>>> according to orography"s slope.
>>> We saw that for such problems usually the function MathEval is used,
>>> but
>>> in our case no analytic expression is available for the orography
>>> description.
>>> Is it possible in gmsh to define the local density of the mesh as a
>>> pointwise defined function? Or could you please suggest us some
>>> alternative solution for refining the mesh using only pointwise
>>> information about mesh size.
>>
>> Does tutorial 7 do what you want?
>> http://gmsh.info/doc/texinfo/gmsh.html#t7_002egeo
>
>
> --
> Giovanni Tumolo, Ph.D.
> Earth System Physics Section
> The Abdus Salam International Centre for Theoretical Physics (UNESCO-IAEA)
> Strada Costiera 11
> 34151 Trieste, Italy
> phone: +39 040 2240 308
> mobile +39 3386533935
> fax:   +39 040 2240 7 308
> http://www.ictp.it/research/esp/members/postdoctoral-fellows/giovanni-tumolo.aspx


-- 
Giovanni Tumolo, Ph.D.
Earth System Physics Section
The Abdus Salam International Centre for Theoretical Physics (UNESCO-IAEA)
Strada Costiera 11
34151 Trieste, Italy
phone: +39 040 2240 308
mobile +39 3386533935
fax:   +39 040 2240 7 308
http://www.ictp.it/research/esp/members/postdoctoral-fellows/giovanni-tumolo.aspx
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