[Gmsh] question about CharacteristicLengthMax

[Peter Johnston]

Hello,

I was under the impression that CharacteristicLengthMax was used to control the mesh size in gmsh. However, I seem to he having some issues.

In the attached python script, I read in some STL files that define surface. I then define some volumes and then mesh them. If I do not set CharacteristicLengthMax I get a volume mesh as shown in no-max.jpg. This is OK, but I would like some more nodes within and around my heart. If I set CharacteristicLengthMax=0.5, then I get a similar mesh around the heart, but it is finer away from the heart (max-0-5.jpg). However, if I set CharacteristicLengthMax=0.05, then I appear to get rubbish, especially around the heart (max-0-05.jpg).

Clearly, I have missed something.

I also tried to use a ball around the heart region, but that didn’t achieve anything. Given the above comments, I was unsure what to put in for VIN and VOUT.

Any thoughts would be much appreciated.

Thank you,

Peter.

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Associate Professor Peter Johnston (FAustMS, FIMA)
School of Environment and Science
Griffith University | Nathan | QLD 4111 | Technology (N44) Room 3.19
T +61 7 373 57748| F +61 7 373 57656 Email p.johnston at griffith.edu.au
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