I am having the same issue with my project. I used the Hex-dominant meshing because it is the default one for CFD. Do you have step by step instructions on how to manually create a mesh?
Getting back to you as soon as possible, give me some time to investigate your case.
Here are my concerns:
You should close the outlet of your geometry as well as the small hole from the inlet. Additionally you will see that when you try to mesh the geometry right now that plenty of parts will vanish. If you make the geometry “watertight”, namely close all the holes that I previously mentioned you will see that the outer layer of your double-layered geometry will be deleted. Simply delete the outer layer and you can keep the round cylinder in the upper half which won’t affect the meshing.
Have a look at this demo case: https://www.simscale.com/projects/demo2/cfd_homework_1/ - here you can see that if you hide one face that there is no other layer, just one!
Does that make sense to you? So the most important points are:
- One layer for the sake of having a clear and distinct modeling approach.
@CFD-SQUAD, your impetus is highly appreciated here. Also let me know if I missed something important!