Heat conduction in GEOM in BFDS

[ESett5555]

Hi everyone,

First of all, I want to thank Emanuele Gissi for this Blender add-on, which simplifies a lot of things while working with GEOM in FDS.

I have been using BFDS for the past few weeks, and I have a little question about how BFDS handles GEOM geometry, regarding the geometry we see in Edit Mode on Blender. I made a test geometry on a CAO tool that consists of a vertical hollow cylinder with a dome on top. I exported then imported it in .glb format and I used QuadriFlow Remesh to get a solid mesh that satisfies me.

When going into Edit Mode, I can see that there are 2142 vertices and 2140 faces. When clicking on Show Geometry on my GEOM volume in BFDS, it looks like BFDS divide all quadrilateral faces into triangles. If I am correct, there should be 2142 vertices and 4280 faces.

But when I try to show code, it shows :

Does BFDS remesh the solid GEOM with the cartesian mesh specified in Domain? Or does it remesh it with any other mean?

Thank you for your answers, and have a great day !

[ESett5555]

Hello again,

I took time to look into the source code, and I think I found the answer in source/lang/ON_GEOM/ob_to_geom.py :
BFDS does not remesh the solid GEOM in any way. It writes a .bingeom with the vertices, edges and faces you can see while clicking on show geometry. If you have any quadrilaterals or other types of faces, it simply triangulates them.

To display the number of vertices and faces you can see while clicking on "Show Code", the code uses len(fds_verts) and len(fds_faces), but :

• fds_verts is a flat list of the coordinates of each vertex, meaning its length is 3 x nb_verts
• fds_faces is a flat list of vertices index, where each face is define by 3 vertices, meaning that its length is 3 x nb_faces

This means that the numbers displayed while clicking on "Show Code" are three times the real number of faces and vertices. If possible, I think that it would be great to address this minor UI issue with a division by 3 directly in source/lang/ON_GEOM/ob_to_geom.py .

Have a great day !