Rule Interpretation - Double deck diffusers

[myurr]

This could get messy

Great leadership shown there by Mosley. What the hell is the FIA for if not to provide a solid framework for F1 that avoids these ridiculous situations? Frankly this is 100% the FIA's fault, and reflects very badly on Mosley.

[nudger]

Isn't Ross Brawn the chairman of the OWG? Or does he chair another group?

i think that may be true...at least he has some admin role.
the technical work was done by mclaren renault and ferrari though.

[imightbewrong]

A question regarding the brawn diffuser. The rules state that:

3.12.7 No bodywork which is visible from beneath the car and which lies between the rear wheel centre line and a point 350mm rearward of it may be more than 175mm above the reference plane. Any intersection of the surfaces in this area with a lateral or longitudinal vertical plane should form one continuous line which is visible from beneath the car. A single break in the surface is permitted solely to allow the minimum required access for the device referred to in Article 5.15.

In this picture you can clearly see that there is an opening in the surface:


This hole is probably right on the rear wheel center line, right? And being exactly there it finds a neat loophole in the rules. As far as I can tell there is nothing in the rules stating that the surfaces before and after the rear wheel centerline must be connected and they have simply made two separate surfaces that are not really connected.

Is this how they have done it or am I completely out of line here? If it is this way then it would be a piece of cake for FIA to simply clarify the rules and say that the surfaces must be joined.

[Shaddock]

Would it be possible to join the endplates to the diffuser without losing the diffuser width as below



You would still have the extra channels outside of the endplates, with the main gains coming within the central section?

[ISLAMATRON]

defiantly worth trying at least in CFD

[wesley123]

yep, that idea is worth a CFD, i think it will work, but only if you pull the whole end plate all the way down. I guess this will increase interactrion with the diffuser and wing

[donskar]

From a translated interview with Domenicali, appearing in another forum, without attribution, Domenicali was asked:

We're now in the paradoxical situation in which Brawn is head of technical matters of the FOTA while at the same time his car has a diffusor that's being questioned by at least 7 out of 10 teams. Is it legal according to Ferrari or not ?

[SoliRossi]

http://www.paddocktalk.com/news/html/mo ... =1&catid=1

"Seven teams - including Red Bull - are united: they are illegal," said Marko, raising the probability of a formal protest at the scene of the season opener this weekend.

He claims both Renault and Red Bull discussed the legality of a similar aerodynamic concept with the FIA early last year and "at that time there was a negative answer".

Now im not sure how legit this site is...but the story originated here http://www.sportnet.at/red_bull_protest ... brawn.urla

If this is legit then the Diffusers for Willy, Toyota and Brawn give them .5 per lap!!!! That is light years.

IF this is the case why have the other teams not copied them?? They must be pretty confident that the FIA will disallow them other wise its a massive gamble to take. Surley the teams have all been fabricating up their own interpretation to bolt on if they get the green light.

Now here is a question for the boffins.... could a similar concept difusser fit on the other cars? ie is the rear rain light/crash structure in the same spot on all the cars or is the rear crash structure slightly higher on the Williams and Toyota?

Also with Red Bulls interpretation could they incorporate a similar design in some way or form?

[donskar]

If this is legit then the Diffusers for Willy, Toyota and Brawn give them .5 per lap!!!! That is light years.

IF this is the case why have the other teams not copied them?? They must be pretty confident that the FIA will disallow them other wise its a massive gamble to take. Surley the teams have all been fabricating up their own interpretation to bolt on if they get the green light.

Now here is a question for the boffins.... could a similar concept difusser fit on the other cars? ie is the rear rain light/crash structure in the same spot on all the cars or is the rear crash structure slightly higher on the Williams and Toyota?

Also with Red Bulls interpretation could they incorporate a similar design in some way or form?

You can't just slap a diffuser on a car and assume it will work -- it's just one part of the whole aero package. I'm sure our more technially adept members can explain in detail (and already have).

The 7 out of 10 number works, right? Brawn + Toyota + Williams being the "three."

[SoliRossi]

sorry i cant source this any more than i came across it at www.markwebberforum.com

Anyhow gives a good idea about the differences, but once again can one of you knowledgable people tell me if the other teams will be able to 'bolt' one of these on?

As donskar said, it has to work with your whole package, which i get but lets just assume that its a better option to use for said car (Ferrari or RBR) then are therer crash structures in a position to allow the instilation?

[myurr]

That diagram is a really good illustration of what the other teams have done and how it is certainly against the spirit of the rules if not the letter.

I am not an aerodynamicist but just bolting one of those diffusers is not guaranteed to work as they require a certain amount of airflow from under the car. In much the same way as McLaren are rumoured to have been having issues with either their rear wing or diffuser stalling due to inadequate airflow directed at them from the front of the car, just bolting on one of these diffusers would likely result in a similar problem. Modifications at the front of the car would be required in order to generate sufficient airflow under the car to make it all work.

I think that McLaren are making preparations to go down that route - the latest diffuser they tested looks remarkably similar to the Brawn diffuser with the central disputed channel reduced in height and filled in. It could be that they are preparing to open up that channel in the event that it is deemed legal - whether at Aus or at a subsequent GP when they can make any requried changes to the front of the car.

[Paul]

I suppose all, maybe almost all, other teams already have such diffusers on standby in case FIA confirms they're legal in Australia. It seems to be too big of an advantage to waste time on complaining while doing nothing themselves...

[Matt Somers]

In my analysis of the BGP001 over on my blog I highlighted the reason why retro fitting one of these diffusers won't work. From front to back the Brawn GP, Williams and Toyota cars have been designed differently. I'll talk about the Brawn car as thats the one I know. The front wing is higher than its counterparts just as its nose is lower. The aim of the Brawn GP is to use the underside of the car and the rear diffuser to generate more downforce (rumoured to be around 10% more) without the front end and floor design the rear diffuser design is useless.

[donskar]

Very nice work, SoliRossi. Thank you.

[scarbs]

I’d disagree with the logic that the double decker set up couldn’t be retro fitted.

The structure around the rear of the car is not such a huge obstacle and can be left intact. In fact it’s a fallacy that the rear crash structure is forming these extra channels. The channels are in an area allowed for the crash structure and the rear of the sidepods, but these components do not form any of the surfaces.

The biggest obstacle would be getting the upstream airflow sorted first, you can a huge diffuser for no benefit unless you get the flow to it correct. Toyota, Williams and Brawn each have reasonably large flow conditioners upstream to replace the function of bargeboards.

For a team to switch to this set up I would imagine a major front end redesign would be required to get enough flow control ahead of the floor