Renault R31

[myurr]

So it's like a blown flap upside down, in effect, accelerating air under the entire floor. Would you see this being coupled to quite a steep rake on the car to, in crude terms, increase the effective volume of the diffuser and help draw more air through?

[Pup]

If it works the way I think it does (no guarantees implied or otherwise), then I think it's more like a wing turned sideways, drawing air from the sides rather than from above or below. So we're talking about just increasing the pressure on top of the diffuser/floor rather than decreasing it underneath.

But it would be a neat trick if they could pull air from below. I think you'd need slots in the floor to accomplish that, which ain't kosher. But who knows - smarter men than I are designing these things.

I don't think there's a problem with the boundary layer detaching under floor, since the rake isn't all that. Maybe at the diffuser, maybe back when they were much larger. So I think blowing the exhaust under the floor would be entirely counter-productive.

But you could easily get the boundary layer detaching on the trailing edge of the sidepods - I'm sure that issue has been discussed here more than once. And what I'm talking about might help prevent that a bit.

[vall]

They can overcome it partially with ignition retardation providing somehow constant flow.

That was my question as well. I'd love to see the underside of the R31. If this exhaust solution proves to be "the next big thing" Renault may have a few races before other teams devise their own solutions. It appears a lot of the magic of this system may be occurring underneath the car which is hard to see unless Kubica or Petrov pull a "Mark Weber."

but wasn't the floor supposed to be plain flat without holes, slots, winglets, etc.? How could they play with that?

[fausto cedros]

What if they were simply trying to improve the flow to the smaller rear wing and to the top of the diffuser by simply drawing away the exhaust and the related crossflow problems? Will that make renault easier to be closely followed next year? I generally think that longer exhaust pipes decrease engine performance, by the way... so the deal must have been relevant.

[mx_tifoso]

Please direct all of the front exiting exhaust talk to the following thread since the concept is taking over this thread.

viewtopic.php?p=221264&f=6#p221264

[mith]

I wonder about one additional thing. If all that previous speculations are correct, how are they making hot air travel under the floor to the diffuser, when exhaust pipes are pointed sideways rather then directly to the back? Wouldn't it make it escape at sides instead of going to the back of the car?

Or are they maybe able to sculpture some 'tunnels' in the floor? I thought floor has to be flat, but maybe it's not that it must be flat but rather it can't have anything below it's level, but can be curved to the top. Normally teams wouldn't be doing it, because they want floor as low as possible. But for that purpose, maybe it would be feasible? I have something like that on my mind:



P.S. It was actually made with GIMP and on Linux. I don't even have MS Paint here It looks so bad, because of my total lack of drawing skills.

To mods: You asked to move FEE talk to another thread while I was writing this post, so feel free to move it there with earlier posts. But until now I will post it here, as it's answer for previous discussion here and is rather pointless without context. And sorry for my misbehaviour

[mith]

Oh, and I have read interview with Petrov where he stated, that their problems today were connected with brakes rather than exhaust. He was also asked about whether it works or not, but said only 'everything's fine'.

It was exclusive for Polish site, so here's google translate link: http://translate.google.pl/translate?js ... ml&act=url

EDIT: I've just read in the another article on that site, that Boulier's saying FEE was working fine and they didn't notice any anomalies in the temp sensors. What's more he said they also did little KERS test. It's surprising, because I thought it wasn't put in the car for the first test. They've also tested movable flap and it's also working. Here's the google translate link: http://translate.google.pl/translate?js ... ml&act=url

[manchild]

I thought floor has to be flat, but maybe it's not that it must be flat but rather it can't have anything below it's level...

No, it must be flat. No curvature, absolutely flat plane.

[mith]

I thought floor has to be flat, but maybe it's not that it must be flat but rather it can't have anything below it's level...

No, it must be flat. No curvature, absolutely flat plane.

OK, I believe you, but my idea came from curved up edges of the floor which are quite popular among various teams. How are they making it legal?

[forty-two]

I thought floor has to be flat, but maybe it's not that it must be flat but rather it can't have anything below it's level...

No, it must be flat. No curvature, absolutely flat plane.

OK, I believe you, but my idea came from curved up edges of the floor which are quite popular among various teams. How are they making it legal?

+1
Good question. Perhaps there's exceptions allowed in the front section?

[marcush.]

there is a maximum radius rule allowance at the corners of the floor methinks.

what about mechanics and drivers when the engine is running? I bet we will see some hot air dancing when things get a bit hectic ...

[manchild]

I think Scarbs' explanation is ok as far as it considers approximate position but nothing further than that. No pun intended, just my thoughts.

Orange temperature stickers are glued exactly where he said that the exhaust pipe is pointed out. I think that if that would be the case than whole area would be covered with heat resistant material rather than painted.

What I think is that stickers are glued to a tunnel which no one mentioned. There is clearly a tunel or a pipe, call it whatever you want - a space around the exhaust pipe to enable entrance of air in order to cool the exhaust. Its exit can be seen where sidepods end (boxy shape).

I still claim that exhaust pipe isn't reaching all the way, isn't pointed forward, but bended to blow into several tiny tunels sculptured on top of the floor, which than distribute the gasses below the car to create virtual skirts, and above the floor to generate more downforce as they hit the lip of the floor bent upwards, as well as to aid virtual skirts below the floor as they travel over undercut and floor's longitudinal edge.

[manchild]

Good question. Perhaps there's exceptions allowed in the front section?

No exception regardless on position. The curvy bits you see on front or sideways are not below bodywork. Floor must be flat only if there is bodywork above it. They can bent it upwards where there is no bodywork on top of it (anti ground-effect rule).

[forty-two]

Good question. Perhaps there's exceptions allowed in the front section?

No exception regardless on position. The curvy bits you see on front or sideways are not below bodywork. Floor must be flat only if there is bodywork above it. They can bent it upwards where there is no bodywork on top of it (anti ground-effect rule).

So there is an exception, but based not on position, but instead on whether or not bodywork is placed above it?

[marcush.]

to me the thing looks like they are blowing the cup holders with the hot exhaust gas .These are airfoil shaped and in side view of the car you can even see how the profile forms a gurney -even if it´s longitudinally orientated.
With the exhaust blowing this wing section this generates downforce ,downforce close to the leading edge of the sidepod,near the CoG of the car this cannot be a bad thing even though ,admittedly the span of that wing is not big.

But what about the outer boundaries of this airflow? will it follow the undercut of the sidepods ?

If nothing else hot air is considerably less dense than cold air .So putting hot air into areas of positive lift or not usable for producing downforce due to their shape this could be used to reduce drag?