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[Alex Chiella]

Hi all!

I was having a look at the CAD Import tutorial for Fluent, and I was wondering what's the difference between those two inputs.
I did understand something about 0 value being a "toggle off" input for Tolerance, making the tessellation the coarsest possible in that regard when chosen. I also payed attention to the rule of thumb of having said Tolerance be 1/10 of the intended minimum (tile?) size.

But none of that makes much sense to me without understanding what Max Size does. I understand that it makes for a finer tiling too, and that either one can be used, but I'd rather know the different ways in which they let the user achieve said results.

In the tutorial, faceting refinement was obtained modifying just the tolerance first, switching it from 0 (off) to 0.01. Then, similar results were achieved leaving the Tolerance off but lowering the Max Size.
Again, this clearly showed that both can be used, but with hardly any idea about what's the governing logic behind it.
It looks almost as if they were redundant upper bound size values, since the coarsest Tolerance 0 still lets you lower the Max Size indefinitely and vice versa...

So yeah, I'd love to learn more about it!!

[Keyur Kanade]

Fluent Meshing does not have CAD kernel. So when you import any CAD geometry in Fluent Meshing, it converts it into facets. As geometry may have curvatures but facets do not have curvature. So to represent geometry correctly, facets are refined further. Default values work best in most of the cases. If you want more refined facets then tolerance value must be decreased. Please note that lowering tolerance values will increase number of facets and file size. Please go through help manual for more details 

Regards,

Keyur

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