Very thin boundary layers and y+ on complex geometry

[DaleKramer]

@Get_Barried

Absolute tolerance 1e-15? That seems way overkill.

@Get_Barried AHA, I finally found Dylans explanation that I think sortof relates to the Absolute tolerance 1e-15 and for sure, the larger relative tolerances that I use, basically for quicker convergence in steady state analysis’s :

@dylan

It is very useful to use a large relative tolerance in steady state, because in this case it is the initial residuals at the start of each SIMPLE loop (time step) that matter, rather than the final residuals at the end of those loops. With a large relative tolerance, the solve will then quickly move onto a newer SIMPLE loop and therefore the initial residuals will drop more ( with more iterations ). The same outcome can be achieved by limiting max number of iterations within each loop.

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EDIT on 11-2-2023: The project where this WHOLE topic is mostly summarized is located here: 'Crop duster lateral stability' simulation project by jhartung
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