[openThanos]

Good morning,

Im new to the forum, thank you for having me. I anticipate that this is not a previously covered topic because Ive done my due diligence searching high and low. I apologise in advance if Im repeating.

I'm new to openFoam; at the stage where I've challenged myself to model my own geometry from scratch (on the framework of the motorbike tutorial). Using the motorbike tutorial as a framework and following Calum Douglas' tutorial (https://www.youtube.com/watch?v=ObsFQUiVi1U) for guidance with my own geometry (grabcad sourced exhaust manfd.)

I am able to 'mesh' and start the run making it a few iterations before diverging. I suspect this is due to my mesh. More specifically, when looking at the mesh in paraView, the inlet and outlet boundaries are patch and discontinuous. That is it appears that not every node on the boundary is associated with the inlet region. Please see attached photo. I suspect this needs to be fixed - and have been working at it for a few days now. Ive been trying a few different parameters in my shmDict, surfFeatExtractDict, surfaceFeaturesDict, blockmeshDict. They do influence the outcome, but not drastically.
Can anyone help me figure out why this is happening and help me fix it?


Notes on the geometry:
The geometry was imported to solidworks and exported as three asci STL files; one solid domain encapsulating all geometry as a solid [volume.stl], and two surface STLs for the inlet [inlet.stl] and outlet [outlet.stl] . I created a fourth merged geometry by concatenating these STLs [merge.stl] and am using that for my 'surfaceFeaturesDict' but not my 'surfaceFeatureExtractDict'. I should not that using volume.stl instead does not change the outcome.

Having exported these stl files independently, I suspected that variations in the exported geometry may be causing this. I used blender to create new inlet and outlet meshes as carbon copies of the volume mesh in the respective regions. This did not change the outcome. The regions are still patchy.


Do you folks have any insight or recommendations? Happy to elaborate or provide the case files.

Many thanks!
Thanos

Please see attached for shmDict, surfFeatExtractDict, surfaceFeaturesDict, and blockmeshDict