Renault R31

[luca]

Of course, if you do introduce exhaust gases so far upstream of your rear tyres, you need to be very careful the plume does not spread so much as to "boil" the tyres. That is not something that would be apparent in a windtunnel, and given the known limitations of 2 eqn turbulence models and jets, not something that I would feel comfortable relying solely on CFD for. But I'm quite sure Renault would have considered all that (if they did go with a weird location)...

That's exactly what I was thinking.

[SLC]

The exhaust gases would not be pointing fowards (as in, against the direction of motion) - this just doesn't make any sense.

And CFD analysis would be good enough to make sure the tyres don't melt!

[kilcoo316]

And CFD analysis would be good enough to make sure the tyres don't melt!

To be honest, I don't think it would be... not with all the transient behaviour going on in the "freestream".

If you look at the accuracy of CFD sims of jets into cross-flows, they are ok... nothing more (google it, there should be a load of papers about on it, its a popular test of numerics).

What is happening in an F1 car, under say braking, is so much more complex.

[SLC]

And CFD analysis would be good enough to make sure the tyres don't melt!

To be honest, I don't think it would be... not with all the transient behaviour going on in the "freestream".

If you look at the accuracy of CFD sims of jets into cross-flows, they are ok... nothing more (google it, there should be a load of papers about on it, its a popular test of numerics).

What is happening in an F1 car, under say braking, is so much more complex.

It is accurate enough, I've done it Granted, the simulation may not have been perfect, but the work ensured that no bodywork nor rubber overheated.

[Tim.Wright]

The material on splitter is definitely for protection from heat. Perhaps they've presented only blank cover with no outlets at all?

That material on the splitter is just kevlar in the laminate. Its quite common for teams to use carbon kevlar on parts susceptible to stone/debris damage since its a tougher material than carbon. Have a look on the little flaps on the Ferrari under the wishbones.

Its definately not heat protection in itself.

Tim

[horse]

I think the concept is counter productive. Blowing upstream should only be done on top of the floor. If it's bellow the heat wont be good for the car and the high pressure coming out the engine can cause the floor to lift. Blowing high pressure turbulent air underneath the car can't be good.

But hot air, in itself, is at lower pressure than atmospheric, so it should improve the efficiency of the floor if hot air were to flow underneath.

It only works in a diffuser throat, downstream, becuase of the ejector principle.

What is the ejector principle? Surely just exciting the air forward of the diffuser opening will get the same positive effects as blowing directly into the diffuser.

[PlatinumZealot]

I still think pointing the exhaust forward on THIS PARTCULAR car is BS! There are some tricks that you can do with it as kilcoo said. But, Insulated or not I cannot imagine 2 red-hot 900 degree Celsius three inch pipes sandwiching the driver's thighs in that space.

Then there is the hole, why is it square? That is a poor shape for that purpose.
Square holes produces turbulence. This is one of the basic things you learn about ducts in fluid dynamics or HVAC.

@horse..

Hot doesn't mean low pressure.

[youtube]http://www.youtube.com/watch?v=9bcArT6T ... re=related[/youtube]

An F1 car is doing this on a smaller scale. So you will literally be pushing the car backwards with the exhaust.

[dren]

I am expecting a very trick EBD once the team fits the exhaust for the first test. I don't think it is routed to the front of the car.

[n_anirudh]

The beam wing is split in the central section as a 2 element airfoil. Wondering if this is legal as its in the central section?



And a fairly large number of slits 6 on the rear wing

[horse]

@horse..

Hot doesn't mean low pressure.

An F1 car is doing this on a smaller scale. So you will literally be pushing the car backwards with the exhaust.

Aye, granted. But what about once the gases have escaped/mixed a bit? Would they still be at high pressure? And if you exited sideways would this not balance on either side?

(I'm struggling to believe it's true, by the way, but I'm interested in testing the hypothesis)

[djos]

Scarbs seems to think there may be some exhaust being routed to the front of the car, personally I think this sounds very far fetched but he's usually right about these things.

[manchild]

Perhaps they use exhaust(s) positioned at the front as virtual skirts?

I mean, since volume and speed and exhaust gasses is mush faster than speed of car, perhaps the gasses could prevent spilling of airstream sideways? Having them spilled sideways would be no loss since they need to go somewhere anyway, and if they could at least partially seal the space between stepped floor and the longitudinal outline of the floor (at least at the beginning of the floor), than the air traveling below the floor would be less spilled, right?

I mean like these small vertical fins on top of airplane wing that serve for same purpose, only "virtual" since floor must be skirt-less, flat that is.

[scuderiafan]

I noticed that little piece in the center of the rear wing, has someone gone over that?

[FerFa]

...should be the connection for the wing switch, no?

My theory about the front exhaust is, that we only can see air inlets, but not the exhaust outlets. The exhaust outlets will be under the car. With increasing speed the air pressure into the angular inlets increases. This leads to a somehow different stream of the exhaust air trough under-body and diffusor. This is a "F-duct like exhaust stream bender", creating more down-force on the rear suspension at high exhaust pressure but low speed and less at high speed with low exhaust pressure.

Brilliant...

[mx_tifoso]

BTW, these calipers seam unusual, as they seam to cover almost 50% of the disc.

[img]http://img534.imageshack.us/img534/5476/new14c.jpg[img]

The calipers are surrounded by cf molding, as per the usual brake system cover but just extended out that far. IMO.

They are coolings ducts which bring air from the drum plenum on the inboard side of the disc out and over the disc onto the outboard side of the caliper.

Right on, I should have specified more. Thanks for adding to my bit though.

http://img534.imageshack.us/img534/5476/new14c.jpg

Why is the caliper not at the bottom?

Maybe worth your while:
F1T - Position of a caliper