Could one of the forum engineers provide some insight into how teams scale the "60% model" test results to predict the results on a "100%" F1 car?
Do they use standard texts or tables?
Does each team create their own secret formulas?
And, is this more experience, practical knowledge from previous seasons... is it more art than calculation?
And secondly, do the teams also test individual parts, like a front wing, as a 60% model or would they build the 100% size wing. Or both? I'd guess they'd want to test the new r&d parts on a complete car - so they'd use the scale model. And then test the real part at a race. Anyway, thanks...
Yes 'JetSki', it's a mixture of all things and the 'scaling factor' is a fairly common formula. Each tunnel though, is different and a great deal of time & effort is put into measuring results consistently. - That's the Holy Grail. Rolling roads that can yaw & adaptive walls all help to achieve realistic results. The best models can steer, pitch, roll & yaw & even blow hot air through the exhaust pipes. All good for measuring transient conditions such as turning into corners, braking & acceleration effects on the underbody aero, crosswinds etc. Tyres are pneumatic & designed the replicate the 'squished' shape they take on - very important, believe it or not.
Model sizes have increased over the years & 60% was a size that some better off teams felt they could justify & afford. (Requires vastly stronger model & support components & more power to run the greater volume of tunnel air consistently. Indeed, the bigger tunnels that are used in F1 require electricity generators that could easily power a small town.
These days, most areas of the car are simulated by 'full size' CFD before being verified with tunnel parts. (One organisation claimed to design a sports car using CFD only. They managed to keep secret the fact that there was a wind tunnel program going on in another country..)
Running wings & other components on their own isn't particularly helpful because every component has effects on other components. A front wing for example will have effects that influence the rear of the car. Most things are looked at in the whole.
Those mechanical components that can be, are tested in the R&D department before being signed off for testing at the track. (Usually in the Friday practices.) The effects of aero component parts can only be finally verified on car & it's not unusual for new components to be junked when the effects are not what they were predicted to be. Loadsamoney is wasted on wind tunnel components - but that's development & the spend is justified by results.
The F1 cars being designed for 2014 will require more work because of the changes to engine & ERS. This will require greater than the iterative changes that relatively stable rules have promoted. These rule changes will affect chassis rear, & side pods particularly. So there will be plenty of different solutions going on next year.
The results from 60% models are considered good enough not to need the greater expense & complication of larger models, or even full size.
The F1 rules are now that 60% is the maximum allowed, 'wind on' time is restricted, the air speed is restricted & there is a trade off between CFD & tunnel development. There is plenty of wind tunnel capacity going spare now after some huge investments by some teams.
Full sized cars have been used in the past, to verify things but you need a bigger rolling road & have the problem of tethering them. There's a lot of mass & energy to dissipate if something breaks. You'd be shocked if you could see the damage even a 60% wheel & tyre can do, if it breaks loose & goes spinning down the tunnel!
Hope I didn't bore you with stuff you already know.
Regards
DogEarred
