(Barely) acceptable growth rate
 

I'm trying to reduce the cell count in my stent model, whose intricate geometry that requires a ridiculously high resolution on the wall. The interested quantities are only on the wall (wall shear stress) and no where else. Since the growth rate has a big impact on the cell count, I wonder how far I can raise it. I know that the best practice is to keep it no higher than than 1.2 (20%), but in my desperation I have raised it to 1.25 in my minimal model (the actual one will be 42 times as large) without much impact on my result. I am tempted to raise it further until I can't without affecting the result.

Is there an absolute limit that I should not cross under any circumstance? If there's a growth rate at which my results will simply lack credibility regardless of my assurance to the contrary, what is it? Thanks.

This might help

Thanks, but my flow is laminar, so the boundary layer is not a concern.