Rule Interpretation - Double deck diffusers

[feni_remmen]

@femi: you don't need an account, just go to imageshack.us and upload your grafic, you even get bbcode to post it here.

I read the rules on suspensions, so basically with clever suspension design you can create to hole that are covered by the rear wishbones.
I don't see the wishbone that is covering the rearword yellow hole in the picture, how is it legal?

Thanks kNt, I will have a go later.

You don't need any thing to "hide" the hole there as it is behind the axle line... You can do what you want there so long as it complies with other bits of the rules.

[feni_remmen]

If the start of their main diffuser is the minimum rearward position at rear wheel line, and the 3rd deck of Toyota's diffuser starts before that, it seems logical the non DD teams may be annoyed.

1. First opening - seems to be part vertical and part horizontal? It looks like they are taking air out from under the floor, using the gap between the outside sidepod floor level and the central lower floor level of the tub, engine area etc. (??)
2. Second opening - again seems to be part vertical and part horizontal?
3. How is this continous!? Seems like a break in the line to me?
4. What's going on with these scultped bits of the floor?

Astro,
This is a great photo as it shows the rear leg of the lower rear wishbone and the hole it is being used to "create"! The wishbone is the CF part crossing the picture, just above the word RW centreline and the number 1. It crosses from the endplate on the left, all the way to the third diffuser chamber, then then meets the gearbox on the right. The white box extends further forward under that part. I think. I may be missing something, but that is what i see there.

That is indeed a lovely picture. It shows that the team is using both loopholes in the regulations, namely the discontinuity and lack of transition that is allowed at the rear wheel centerline, which allows for the vertical opening labeled as 3 in the picture, and the loophole which allows a suspension member to form a part of the deck of the diffuser (opening 1).

That said, while the design of hole 3 looks "proper", there must be doubts as to how well the suspension member can seal the upper side of the deck, as well as how good is the quality of flow acutally with the suspension member in the channel.

I also don't think that the loophole as used to form the opening 1 in the picture necesarily requires a suspension member to be present. One could simply just open up the floor ever so barely such that there can be a horizontal gap between the reference and step planes close to the hole, which then allows for the two planes to not be joined by a transition, and then one would continue the upper deck of the diffuser above the reference plane at the level of the step plane. There will be a small horizontal gap between the step plane and the deck through which the unwanted air would want to enter from above, but this can be offset somewhat by placing a gurney flap around the hole. Is there a "hole" in this interpretation?

Yes, I've been thinking all those things. Sealing and what you are willing to compromise to acheive it. The seal from the sides of the wishbones would be the tough as the gap would changes frequently without much suspension movement. All that said, it is fairly silly solution, only created by silly rules. This is why F1 sucks these days. The designers are smart, but their compromises are absurd, due to regulation. Anyway, I don't really care about riding that horse.

[kNt]

What do you think of this interpretation? It should add quite a bit of diffuser exit area and also help with rear-wing interaction.
Oh just saw it should say car-centerline not wheel-centerline. Hope it is clear anyway.

[Gecko]

Your solution unfortunately goes against many of the regulations that specify the allowed bodywork, especially in the wing region.

[kNt]

No, I don't think it does, maybe (ok, maybe not maybe ) I didn't make myself clear with the drawing. The channel would be around the centerline of the car, exiting in the zone 7.5cm to each side of the car centerline. Basically it would be above the crash structure and be feed from quite the front (the more forward wishbone).

[Gecko]

Ah, I see more clearly what you mean. As long as you keep your channel within the bodywork in front of the rear wheels then indeed there is probably nothing illegal about it.

I think it is an interesting idea that may again couple the diffuser to the low pressure area below the rear wing. The length of the channels might reduce the effectiveness of the device a bit, and it might create additional drag by widening the body in the areas where it should be becoming quite tight (where you channel things around the gearbox), but I can imagine it could be capable of giving a real benefit.

[kNt]

Here's another try.

I don't know how the length of the tunnel comes into play, but packaging would certainly quite tough to do.

The drag penalty could be decreased by incorporating an oilcooler or something similar into this.

[Gecko]

I was also just about to suggest that it would probably be worth it to extend it all the way down to the gearbox, but you beat me to it .

Oil coolers and such are a bad idea, you want as clean an airflow as possible through the device. As I said, there is certainly going to be a bit of a drag penalty, but it might be that the benefits far outweigh this. With the way you've drawn it now, the additional frontal cross section surface is all covered by the diffuser when seen from behind anyway, so it's hardly a dead area.

All in all a very original idea! I wouldn't be too surprised to see some variation of it on actual cars.

[Metar]

Couldn't they incorporate it into an RBR-style Sharkfin?

[kNt]

I guess it could have some of the same positive effects a sharkfin has.

I've drawn up another picture from behind with a multi deck diffuser.

[Metar]

Just what I had in mind - a gargantuan venturi that also serves as "that single opening" - assuming, of course, packaging allows such a whacky arrangement.

[kNt]

I think I found some more possible loopholes.



If the rearwheels are moved inward a little the beam wing (lower rear wing) could be connected to the brakeduct area and made full width.


Lower down the Diffuser could also be connected to the brakeduct area to expand it.

Another thing is some wheel-rim-fan (used by toyota last year) could be used to extract air from the diffuser (along the red arrows).
The wheel-rim would be a fan and some ducting can be used to guide the air trough the wheel and around the rear brakes.

[aguri]

New RBR5 DDD feeder:

[Callum]

New RBR5 DDD feeder:

It seems to me to have proper scoops... rather than just a hole but maybe its just the picture.

[djos]

New RBR5 DDD feeder:

It seems to me to have proper scoops... rather than just a hole but maybe its just the picture.

Yeah they are scoops alright! Nice Work Newey. =D>