jjn9128 wrote: ↑29 Jul 2020, 17:22
Hoffman900 wrote: ↑29 Jul 2020, 15:31
With the struggles F1 teams have correlating their wind tunnel to CFD to real world performance, it will be interesting to see how these cars perform in anger.
A lot of the correlation issues in the wind tunnel stem from wall interactions - i.e. when pushing the front tyre wake outboard the outwash hits the wind tunnel walls and straightens more than it would at the track; and tyre squirt from the bulbous high aspect ratio tyres. With less outwash and lower profile tyres the correlation
should be simpler.
The bulbous tires and barge boards aren't anything new, and some of the wind tunnels were built after their existence. This is the whole reason for adaptive wall wind tunnels, scale models, etc. I have no doubt this isn't the full issue and part of it is that CFD is hard. I know a Boeing aerodynamics department manager and they struggle with it at times, and with resources that are more than the F1 grid combined, several times over. The amount of computing power needed to approximate the real world is staggering, and even with the best systems, it still can't fully replicate it.
As we all know, models are useless without correlation, be it CFD, FEA, engine pressure dynamics, etc.
A NASCAR builder I was listening to talk mentioned how despite all the R&D they do, and having great engineers, stuff still doesn't work out like what was thought on the computer screen. Those guys have the benefit of long term static rule set so their models are
very well correlated. His words are the engineers come back with "but it's dimensionally correct", but sometimes it just doesn't work, and it's back to the drawing board and remeasuring and reworking their models to understand why and find further improvements.
It's fun to talk about, but with the hype surround the rules package and the better racing, I worry we're headed for a NASCAR COT situation when things don't play out exactly how people think or have been hyped.