Crazy idea for flaps and chicanes

[Ciro Pabón]

Warning! Long post filled with photos...

First: a lifted kerb

Well, you all saw Kubica's car crash. On Saturday, before the race, I received, out of the blue, a couple of photos from Manchild, like this one (photos that I saw after the race):



The first thing that came to my mind is "the kerb is wrong". Notice that is shaped like a bump, instead of "going flat". A normal suspension at 120 khp cannot follow the shape of the kerb (yes, I know that's the idea of kerbs, but...).

Now, if the green mat were "lifted" and it "filled" the "hole" formed on the ouside of the kerb, that problem would be solved (not mentioning that the car would be "tilted" towards the track, instead of launched into the blue sky...).

Second: a flapped underbody

I've seen "NASCAR flaps" for ages. They are something like this (invented by Jack Rouse of the University of Michigan, bless him):



When the car generates lift, low pressure air above the flaps pulls open the first flap, shaped like a wing. Once this flap opens, it kills the lift.

The high pressure area in front of the first flap is connected through a tube with the second flap, and this high pressure deploys the second flap to kill the lift as the car rotates. I quote: "the roof flaps keep the cars on the ground as they spin... allowing the driver to regain control. If not, at least the speed is reduced before the crash."

I think you must have seen the "old style" NASCAR crashes, where a car started to spin slowly and suddenly it lifted itself from the track and started to tumble like a rolling dice down the track: Mr. Rouse's idea ended that.

Thinking about that, I came out with this contraption:

Ciro's Flap


I tried to depict a cut of the underbody of the car. There, I imagine a rotating flap (in this image it can only rotate counterclockwise), sucked down by the low pressure under the car (?). This low pressure holds it in place when the car is running normally, because the rear part, behind the axis of rotation, is larger than the frontal one.

When the car gets airborne, the air hits the underbody, creating high pressure (?) and opening the flap. Air flows through a vent behind it.

This flap is shaped like a wing, creating lift to rotate a second "lift killer" flap. This would create drag on the back of the car, pointing the nose down again. I call this, with all the modesty that characterizes me, "Ciro's flap"...

When the car flies, it deploys automatically a kind of spring-loaded "air brake", if you follow my drift.

Of course, the car, once it hits the ground, finds that the run-off areas are paved and, hopefully, allow the driver to point the car into a better attitude for a crash... Grass run-off areas are ridiculous, if you ask me: they're like putting ice on the sides of the track. Which leads me to:

Third and final: a twisted chicane

Now, about the chicane, I'll try to be concise.

You all know the graphs you can make of a car acceleration capabilities, called a G-G diagram. They are like this:



From this diagram you can find the possible trajectories of a car (including the limit case, when the car goes straight because is flying).

Now, I hereby proclaim that putting a wall on the envolvent of all possible trajectories is not a good idea, if you follow my drift again.

That's why I came with this second idea for chicanes, that, again, I baptized modestly as "Ciro's chicane":

Ciro's chicane


As you can "clearly" see, on the left is the "Mosleyescan" version, and on the right is the right one, my version of course.

I tried to show how on the first option you have a chicane (in red) that is there supposedly to brake the cars and make safer the Casino hairpin that follows. The envolvent of trajectories (in violet) goes against the wall, in case a car flies over the kerbs.

Now, on the right, I put a large radius, spiral curve and countercurve before the chicane, "twisting it" 45 degrees aproximately and aligning it with the general axis of the track. The envolvent now points straight towards the "safe area" (towards the "right-of-way" of the track).

Notice that what makes the first chicane a wrong solution is how far is the track from the wall.

So, I also hereby sustain that a wall, like the "Wall of Champions", that is inches from the track, is less dangerous than this wall (that eerily reminded some people of Tamburello, didn't it?), perhaps ten or fifteen meters away from the track.

I think that a close wall, like Monaco's, "deflects" you, while a far-away-from-the-track wall "contains" you.

I rather take the first option.

[mx_tifoso]

Excelent information Ciro.

2.) I have seen those "lift killer" flaps in action while, briefly, very briefly (!) watching NASCAR. And by what you have mentiond on your "Ciro's flap" section, it appears as if your application for F1 of that invention would work.

A weakness however, is that they would be extremely susceptable to damage, while riding over curbs, bumpy grass or sand traps. Rendering them "useless" afterwords.

3.) A prime example of a why being contained by a wall is bad, especially at high speeds: San Marino GP 1994.

[zac510]

Ciro, are you sure that this problem of the flying car is actually a problem that needs to be fixed? Any car would fly over the shape of a kerb like that at those speeds, with or without 'Ciro' flaps
I understand it's the nature of an F1 car's underbody that after a little kick on the front that it won't continue to fly - the front will fall back to ground quickly.
Therefore I don't think there is an issue that needs to be addressed.

Although I do like your new chicane very much. The sight of the cars changing direction through that would be great

[Steven]

I don't think that chicane would be a good solution. Although it will be spectacular without a doubt, the overtaking possibilities will be zero. Therefore I don't think it should be introduced before downforce on the cars is limited (and that is not likely to happen in the next few years).

As for the flaps, since F1 cars don't have roofs, where would you locate them?

And btw, I don't think Kubica's accident was caused by the problematic kerb that you mention.

[manchild]

No circuit can prevent cars getting airborne and it is less of a danger than "landing zone" configuration. I'll be pain in the ass again for the sake of the safety and say that neither Ratzenberger, Senna would die if FIA has instructed race organizers to isolate walls with old tyres.

The place where Kubica hit the wall is wide enough to be isolated with at least 3 layers of old tyres barrier and on the left side of the circuit there's space for at least one layer.



Can someone please compare price of that giant screen with how much would it cost to isolate whole hairpin with old tyres? Is it more important to give audience zoomed pic of driver dying or to prevent tragedies?

Why isn't it done so on ALL circuits? Because Max is busy with banning technology and work on environmental friendly F1 while safety and especially the circuit safety remains not just very backward but very disregarded.

I really don't want to hear explanation how "no one expected car to go that way". That can be said only by dilettante who has no experience with racing. Isolate ALL walls and armcos! ALL! No matter how illogical it may seam that a car will hit them. It costs so little and saves life!

Even the most modern circuits suffer from same problem - look how Horrific crash Heikki had in Bahrain. Once again unprotected armco! Shame! Shame on FIA for licensing circuits in such condition! ALL circuits have many weak spots. I hope someone is listening. Perhaps GPDA. I truly hope things will change for the next races.

[Ciro Pabón]

Ciro, are you sure that this problem of the flying car is actually a problem that needs to be fixed?

Yes, I am. There is a study on the subject running right now. You can check at FIA site on safety. I quote:

"New research commissioned by the FIA has revealed that the current design of cars running under sportscar and ‘sport prototype’ regulations exhibit aerodynamic characteristics that can cause them to leave the ground and possibly invert, when they run at yaw attitudes greater than approximately ±30º, even at speeds well below their maximum".

Besides, you can check here: FIA Formula for Safety that I also quote:

Development of the Circuit Safety Analysis System (CSAS)

The CSAS is a computer tool which integrates detailed electronic
image maps for the circuits with lap profile data from sensors fitted
to the cars. Further information, regarding the performance of
run-off areas has been collected from real accidents when cars run
off the track. The CSAS tool is used to evaluate and specify the run-off
areas and safety barriers at all Grand Prix circuits.

Car Launching Mechanisms (“Flycar”)

This project aims to fully understand the mechanisms whereby open wheel
cars, especially those used in Formula One, often launch in
the air when they collide. F1 teams Toyota and Red Bull have supplied
carbon suspension parts and Bridgestone will provide F1 tyres
to aid the project.

Here is the picture at FIA document:

As for the flaps, since F1 cars don't have roofs, where would you locate them?

The flap goes on the underbody, not on the roof.

I tried to explain that this particular "lift-killer" flap works because the pressure changes under the diffuser, in the event the car goes airborne. It seems I failed misserably to make that clear...

[modbaraban]

I completely agree about the flying cars problem:


(sorry for reposting this but this pics simply belongs to this thread)

3. I like your chicane! It's really fun to drive but... the Ciro's chicane is called the S-curves (sorry ) ...and the one you drew won't slow the cars down THAT much becasue it as a slower entry and then a FLATOUT line all the way through the complex. But it should be really fun to drive. and it would clearly work in terms of safety of course.

[joseff]

Does anyone remember one of the proposals years ago to put rollers behind the rear wheels? So that if you hit it with your front wheel, you won't take off.

[zac510]

Ciro, are you sure that this problem of the flying car is actually a problem that needs to be fixed?

Yes, I am. There is a study on the subject running right now. You can check at FIA site on safety. I quote:

"New research commissioned by the FIA has revealed that the current design of cars running under sportscar and ‘sport prototype’ regulations exhibit aerodynamic characteristics that can cause them to leave the ground and possibly invert, when they run at yaw attitudes greater than approximately ±30º, even at speeds well below their maximum".

Sportscar and sports prototype refers to ACO LMP1 and LMP2 type cars and possibly some other closed wheel sportscars like DP. I thought you were talking about F1 cars.
ACO made some reasonably large changes to stop flying cars after the Mercedes incidents.

[mep]

At Ciro Pabón
You didn't fail to explain the flap, I think I understand what you mean
but there is one think.

How do you close the lift killer flap when it's once open?
And it would be destroyed when it was once open and the
car felt back to the ground.
So it could be destroyed by simply riding the curbs witoud the car
flying very much but the causing a unpredictable car behaviour
and may cause an accident itself.
Or just get damaged and then not be able to prevent the car from
flying when a real accident happens.

You may find solutions for this but after all does the flap not
protect from flying it only can make a fly shorter.

Have you seen the Mercedes CLK GTR video I posted in the video
section?
The flap could have helped in an early stadium of the fly
but after the frontal surface of the car has a special (high) angle of
attack is the force turning the car over much more stronger
than the force by the little flap.
The flap then doesn't even point in the direction from the wind
because it would then close the gab from the wing shaped flap.

[mep]

At manchild

I think one mayor problem with tyre walls is that you have
to hit them more or less in an 90° angle to to be well protected.

If you hit them with an sharp angle you bore the nose
of the car in the tyres but get the rear of the car turning around.
This creates a big moment on the survival cell and will crack it
and the driver sitting in it.
(Panis accident)

So for areas where you will have impacts with low angles it's
better to have guard rails who deflect a car.

I know the tyre walls are now protected by a rubber cover but
if it would be strong enough to prefent the car boring in it
than it would be so hard like a solid wall.


I think the best protection for impacts with low angles are solid
but movable walls like guard rails are.
They are not so rigid like a cement wall, they take acceleration energy
and they deflect the car into the running out space where it can
hit tyre barriers in an 90° angle.

[manchild]

What would happen in cases like this one was?

http://www.formel-1.dk/websites/formel1 ... 29high.jpg

[SoftBatch]

I know the tyre walls are now protected by a rubber cover but
if it would be strong enough to prefent the car boring in it
than it would be so hard like a solid wall.

Perhaps the tires could be covered by a carbon-Kevlar material like the fuel tanks use. They would also have to use some sort of netting to prevent the tires from flying out of the tire wall, which will protect the drivers from falling tires as well as hopefully cut down on repair time.

[Ciro Pabón]

I am afraid this long answer will kill this thread... anyway, here I go.

...the Ciro's chicane is called the S-curves (sorry ) ...and the one you drew won't slow the cars down THAT much becasue it as a slower entry and then a FLATOUT line all the way through the complex.

I wrote about that and then erased it, because the post (like most of what I write) was getting gargantuan proportions.

First, the chicane drawn in red is the same. I simply rotated it. It seems that it would allow you to drive through, because I draw it in Word (!), out of scale, but it is much narrower in real life.

The fact is that the S-curves can be made with radii as large as possible, as large as the straight before the chicane allows. If you made them with spirals, you would "narrow" their envolvent.

The chicane after the S-curve would slow the cars even more, because it would be harder to enter it from the outside of the curve: you come from a slight reverse curve, so your car would tend to exit this previous S-curve on the inner part of the entrance to the chicane, instead of entering from the outer part of the curve, as a chicane is normally taken.

If I find the time, I will try to draw it to scale, using AutoCAD. This should show what I think more clearly.

Does anyone remember one of the proposals years ago to put rollers behind the rear wheels? So that if you hit it with your front wheel, you won't take off.

You know, joseff, you always surprise me. You must be some kind of mentat, like tifosi... This idea seems crazy enough to work.

Sportscar and sports prototype refers to ACO LMP1 and LMP2 type cars and possibly some other closed wheel sportscars like DP. I thought you were talking about F1 cars.
ACO made some reasonably large changes to stop flying cars after the Mercedes incidents.

I am aware of what a sportscar and a sport prototype is, the same way I am aware F1 cars have no roof, thanks for your concern.

I mentioned them because it seems to me that the problem they have is the same NASCAR solved with the roof flaps.

Apparently (there is no worse deaf that the one that doesn't want to hear, we say in spanish... ), you did not read the following quote. I repeat it for your convenience: "Car Launching Mechanisms (“Flycar”): This project aims to fully understand the mechanisms whereby open wheel cars, especially those used in Formula One, often launch in the air when they collide."

Finally, you're plainly wrong about Mercedes and control of flying prototypes.

I quote from the link you did not follow (sigh... do any of you follow the links? I mean, besides Carlos... ):

"The problem that has been identified occurs once the driver has lost control of the car and starts to spin. It is different to the problem experienced by Mercedes at Le Mans in 1999, in which the cars took-off while running under normal conditions."

How do you close the lift killer flap when it's once open?
And it would be destroyed when it was once open and the
car felt back to the ground.

... you may find solutions for this but after all does the flap not
protect from flying it only can make a fly shorter.

First, the flap (or whatever FIA comes with) it's there for two reasons: first, as you note, to shorten the flight. Second, it is there mainly to avoid the car from flipping over, like a leaf falling from a tree. Manchild photo illustrates that.

Second, about the flap closing, I think (I'm not an "aero expert") that it opens because the flow conditions under the diffuser change when the car gets airborne, from low to high pressure. I imagine the same low pressure that keeps it closed in normal conditions would close it when the car hits the ground again.

The reason why I drawed the "killer flap" so short is because I imagine it has to fit in the tunnel of the difussor, between the floor of the car and the tarmac, so it won't hit the pavement.

You can also notice that I imagined (I did not write it) that the "killer flap" is spring-loaded, that's why it rotates more than the wing, when it opens. if you look closely at the drawing I made, the "wing" rotates 45 degrees, while the other flap rotates 90 degrees. I imagine this spring can be made strong enough to hold the flap in place while the car is running and calibrated to close it when the car stops being airborne. What keeps the flap open is the high pressure that develops when the car flies.

About the walls, there is a lot of new designs: first, the Indycar and NASCAR approach, which uses walls that collapse when hit (instead of concrete):

Test of SAFER barrier (Steel And Foam Energy Reduction)


You then have "Cellofoam", "PEDS", "IPS" and "Compressible barriers".

Anyway, I agree with you: the best impact is against a deflection barrier, not against a barrier that stops you frontally. This does not depend on the barrier: it depends on the trajectories the track imposes on cars out of control.

[Ciro Pabón]

Perhaps the tires could be covered by a carbon-Kevlar material like the fuel tanks use. They would also have to use some sort of netting to prevent the tires from flying out of the tire wall, which will protect the drivers from falling tires as well as hopefully cut down on repair time.

Well, your idea is not exactly the same, but the idea of tyre wall integrity has already been tackled somehow, like this:



FIA has also developed (through Mr. Hubert Gramling marvelous work) a barrier very similar to the one in the image, like this:

The TecPro blocks were followed by four rows of tyres with a gap of 2m in between. In the middle of the tyres, tubes of high density poly-aethylen were inserted. Behind this was a final barrier, which was a special retaining wall supplied by German company Bernd Spengler. With this barrier a 173 kph impact was managed at a deceleration of 65g. A final crash test in 2006 proved to be the culmination of the previous six years work. The trolley was driven at a speed of 187 kph into a barrier made up of only one line of steelarmed TecPro blocks, followed by a 1.2 m gap (shortened to improve efficiency), then six rows of tyres with poly-aethylen inserts and finally a moveable retaining wall. The whole barrier was just four metres deep and the result was stunning. With a deceleration of 55g for the driver, the load was way within acceptable limits.

The High Speed Safety Barrier
: used in Monaco last year (not that anybody noticed it! )

I wish to add (as if I hadn't written enough! ) that I remembered a paper by Edward Kasprzak, that "develops a theoretical approach to analysing barrier placement relative to a corner, showing that there is a "worst" distance for impact severity and examining the sensitivity to placement closer and further than this critical position." It was shown in 2001 SAE safety conference on racing and I am afraid it has been forgotten (or conveniently passed over when designing the tracks).

We also wrote something about barriers and tolerable G-forces here:

viewtopic.php?t=2415

Finally, Manchild came with a great idea: once the car gets airborne, the propeller starts to turn and propels the car over the barrier, avoiding the crash: