F1technical.net

Metar wrote:I agree - it was visibly easier to follow other cars.

I do wonder, too - will the new diffusers affect the wake negatively? Doesn't the difference in height and volume mean different exit-speeds at different parts of the diffuser, thus creating additional turbulence?

not necessarily, the extra diffusers, if you will, on the williams have a higher angle of attack to the air going into them, making them more efficient at lower speeds, ie creating a bigger wake in a corner than the normal diffuser, and less efficiency at higher speeds, ie it will have no real effect in downforce or wake area when compered to a car with a normal basic diffuser. overall it will be a little harder to follow a car like the williams brawn or toyota into a corner but they will be creating an ever so slightly bigger wake on the straits, but most likely not noticeable enough to anyone driving behind them.

I seem to recall that McLaren did this back in 1997 or 98 but abandoned the approach for much the reasons Wesley123 stated.

Am I right in thinking that all Toyota and Williams have done have reshaped the rear floor and crash structure to create a second 'area' and then add the diffuser to that. If so how's it been passes legal if it exceeds 175mm? Is it because it's classed as part of the crash structure?

chris17 wrote:Am I right in thinking that all Toyota and Williams have done have reshaped the rear floor and crash structure to create a second 'area' and then add the diffuser to that. If so how's it been passes legal if it exceeds 175mm? Is it because it's classed as part of the crash structure?

Quite brilliantly, yes!

wesley123 wrote:letting the exhaust flow into the diffuser is a bad idea, then it gets really sensitive to throtling, when yo odnt use any thirothlle you'll get a big downforce loss.

Good point about the throttle, I guess you'd be in trouble if you had to lift mid-high speed corner in somewhere like Turkey.

Nealio wrote:I seem to recall that McLaren did this back in 1997 or 98 but abandoned the approach for much the reasons Wesley123 stated.

Cheers for the tip on McLaren, I didn't realise it's been tried before.

Would the Rads provide a stable enough heat source?

axle wrote:Yes not exhaust gasses but the more constant temp of the air that been through the rads at removed latent heat might already be in use.

Cool.
To my mind it the 3 controversial diffusers might be best placed to exploit this...

the toyota one seems just taller and longer on the middle section than the regular "renault", which should be legal

the brawn also seems to be meeting all requirements

but, to me, the williams diffuser doesn't seem to follow this rule:
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

in any case, the brawn design seems much better, if not just because the car is faster, then because, unlike the williams one, it looks decidedly simple, which is usually a feature of good engineering

what I see looks like a regular diffuser, plus somethink like a spoon on the middle section, which maybe accelerates the air that comes from the sides (if the air flowing over the spoon comes from the sides), maybe accelerates the air that comes from below the driver (if the car structure is working as a diffusser, with an air input that comes forward to the standard diffusser, if the bottom part of the car becomes higher before the diffuser starts -at a lower height), or maybe it is just like the spoon they don't let him use in the front wing anymore (which might create a high-pressure section above the diffusser, increasing the pressure differential but just in that area)

the first one shouldn't be outrageously efficient, as the sides of the undercar are higher and an acceleration of the air flowing there is more difficult to achieve, and the third one would only increase downforce on the limited-surface area of the diffusser (which may be where you need it most this year, but wouldn't be great), so I think it's the second one which is most plausible... but then I don't know if you can legally increase the height of the bottom of the car in the middle section, below the motor

does that make any sense?

The main purpose of the spoon is IMHO to meet the regulations. It hides the upper part so that there is no part visible from beneath that is higher than 175mm from the reference plane. It'll surely also work as a guide for the airflow, but that's more a side aspect.

hecti wrote:

n smikle wrote:hmm.. good question.. I am leaning toward the wings to be a cause of that for some reason.


Is it only me? I think those Double Decker diffusers are actually Diffuser + Spoiler all in one. Yes the air has more Area to escape but at the same time there is an extra surface for the air to press down on.

If you look you can see that the diffuser is not only taller but has the extra slanted surfaces going across the middle that make the "decks"

Its about area and volume or, more properly, volume and flow rate(flow rate involves area)

Yes you also get more volume.. I agree.. but let me clarify.

If you look on the regular diffusers such as that on the Ferrari they only have vertical slats.



Look on the extra surfaces on the Williams Diffuser.. they have an angle of attack on them which vertical slats can not provide.
So when air runs over them, it presses the diffuser down.

n smikle wrote:So when air runs over them, it presses the diffuser down.

I thought that might work on the brawn difusser, which has a bigger aperture on the higher deck, but on the williams it's a pretty small aperture, so I guess that wouldn't work: creating a high pressure zone in the higher deck would press down the lower half of the difusser, but would press up the higher half, so the total downforce wouldn't be that high, and you would only increase drag

it has to be something else...

about the brawn one, looking at this pic (from previous post on this thread):

it looks like the v-spoon is directly connected to the reference plane, so on its lower side it works as a difusser for that part; and the air flowing over it comes from the sides, from the gap between the reference plane and the deck plane
before seeing the brawn crush its competition, I'd have said that with so little air flowing over that spoon the effect wouldn't be so great (actually, I'm starting to think there may be some other magic things in that car that we haven't found out about yet)

by the way, about the williams difusser, I correct my previous post: the full paragraph in the regulation says:
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
the upper deck of williams' difusser is not visible from beneath the car, so obviously the intersection need not be visible from beneath the car either
is there any other rule that restricts what bodiwork may exist over the difusser, which could prevent the existence of these difussers' higher horizontal section?

I have no technical experience but I personally think this whole diffuser situation is a big smoke screen.

Their is no denying that the double decker is worth an extra half a second of what ever it is, but lets not forget - if this double decker design is cleared in April this wll enable developers to design a car on a completly new level, and enable them to venture areas they wouldnt have been able to previously explore!

I personally believe that McLaren will be the first to develop their interpretation of the double decker shortly followed by Red Bulll... although im very shocked that Newey didnt think of this idea being the man he is! Maybe he is loosing his touch, although their is no denying tha the Redbull is shaping up to be something special!

I find it arrogant of Dudes like Briatore pretend, that if they were to do a DDD, it would mean a quantum leap and would make the cars far more dangerous. I mean, at first they don't get it right but afterwards they say that Williams, Brawn and Toyota where dumb asses because they weren't able to use the full potential of the DDDs. How stupid is that?

jason.parker.86 wrote:I have no technical experience but I personally think this whole diffuser situation is a big smoke screen.

Their is no denying that the double decker is worth an extra half a second of what ever it is, but lets not forget - if this double decker design is cleared in April this wll enable developers to design a car on a completly new level, and enable them to venture areas they wouldnt have been able to previously explore!

I personally believe that McLaren will be the first to develop their interpretation of the double decker shortly followed by Red Bulll... although im very shocked that Newey didnt think of this idea being the man he is! Maybe he is loosing his touch, although their is no denying tha the Redbull is shaping up to be something special!

Red Bull have already stated that they asked the FIA last year if the double deck diffuser was legal and where told no, that is why they (and others) are so pissed off that now the story has changed!

Look, I'm no aerodynamisist (cant even spell the word) but something things strike me as odd and I see no escape from it by the other teams is this. Actually there are 2 things.

First is you can argue that the spirit of the rules doesn't exist, but it sertainly didn't stop the FIA from ruling by claiming something against it. (aka. Ferrari flex floor, wings). So I don't think that the "umberfuser" teams, can just say there is no such thing. [-X Though I, would want to side with them and state that isn't as well. Rules are black and white and there are no spirits. I and everyone though have seen that the FIA doesn't entirely think that the spirit of the rules doesn't exist. This is another issue all together though as banning on the idea of the "spirit of the rules" is a controversial idea and alone may not be enough for a ban.

There is this issue though of..."the hole". Mainly the starter hole.

Certainly, its a very obvious issue. But the rule still says "solely". Which we all know means "for no purpose other than...X" And designing a hole to create aero effect and benefit, is a real and tangible action.

Some and teams may argue that the hole in of itself cannot do anything. But if they did, then the FIA might tell them that they think it is there for something other than "solely" purpose.

What would be the team's official response to that question?

AKA.....Dear..(insert name here) Is the hole there for the "sole" purpose of starting the motor? They will have to carefuly formulate the response not in simple concrete technical terms, but also to not take the FIA for dumba$$es.

We have seen in the past (BAR fuel tank) the FIA act less than favorably to teams blatantly misleading somebody about the function of a device.

In the case of these diffusers when those questions come up, the answers better be formulated with more than just the premise that the FIA are as black and white as the rule book appears to the reader.

And, surely an answer of..."It's there to circumvent and exploit a loophole created by the allowance of a hole for a starter and in the end generate more downforce" will not fly and spawn plenty of "spirits" to answer to.

Moreover, I doubt that the "protesting" teams, would simply take whatever response they get from the "umberfusers" and stick it right in their face with a response formulated with a "but what about....and we asked you about that before" (Red Bull/Renault).

Just a thought....

Been skulking on this forum for quite some time, thought I'd finally add something.

Might be of some use to those who wanted to hold the bgp diffuser in their hand and have a good look at it. Wondering how this italian lot got such good renderings of it, can they be considered accurate?

Admittedly stolen from the thread discussing these diffusers in the autosport forum.

http://vbox7.com/play:9c408f41

In italian though anyone want to translate.

Very interesting and informative discussion so far, thanks.

jimmy8v wrote:Been skulking on this forum for quite some time, thought I'd finally add something.

Might be of some use to those who wanted to hold the bgp diffuser in their hand and have a good look at it. Wondering how this italian lot got such good renderings of it, can they be considered accurate?

Admittedly stolen from the thread discussing these diffusers in the autosport forum.

http://vbox7.com/play:9c408f41

In italian though anyone want to translate.

Very interesting and informative discussion so far, thanks.

Awesome find! I was wondering how this really worked. =D>