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james

Air Flow Disruption

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I thought of this last night while trying to sleep and after a little refining it seems that it could work quite well. Basically the idea is to use the engine to power an air compressor that can fill up one or more air tanks in various positions around the car. I read somewhere that most cars carry between 50-70 kg of ballast, so the weights of the tanks themselves could be taken out of the ballast. Next you run lines to the bottom of the car that point forward. When the car hits a straight the driver simply hits a button to releast the air. If done right it could probably halt the flow of air under the car almost completely, taking away loads of downforce. And if you didn't want to use tanks you could probably hook up a clutch to the air compressor so it engages when the driver tells it to and pumps out air in proportion to how fast the car is moving. Another thought would be to make the nozzles on the diffuser adjustable so that during braking and cornering they are pointing to the rear to speed up the airflow and increase downforce, then change back when going down a straight.

If the FIA tried to outlaw the system you could argue that its just movable ballast even though the weight of the air itself, if I've done my calculations correctly, shouldn't be more than 5 kg. As shown below compressed air is fully within the rules.

Technical Regulations

ARTICLE 4: WEIGHT

4.1 Minimum weight:

The weight of the car must not be less than 605 kg at all times during the Event.

4.2 Ballast:

Ballast can be used provided it is secured in such a way that tools are required for its removal. It must be possible to fix seals if deemed necessary by the FIA technical delegate.

4.3 Adding during the race:

With the exception of fuel and compressed gases, no substance may be added to the car during the race. If it becomes necessary to replace any part of the car during the race, the new part must not weigh any more than the original

I'd like to hear what you think. Good or Bad. Hold nothing back.

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In theory, possible but I doubt a device like that would quantify as ballast, and I don't think it would be likely to pass a scruitineering check

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I thought of this last night while trying to sleep and after a little refining it seems that it could work quite well. Basically the idea is to use the engine to power an air compressor that can fill up one or more air tanks in various positions around the car. I read somewhere that most cars carry between 50-70 kg of ballast, so the weights of the tanks themselves could be taken out of the ballast. Next you run lines to the bottom of the car that point forward. When the car hits a straight the driver simply hits a button to releast the air. If done right it could probably halt the flow of air under the car almost completely, taking away loads of downforce. And if you didn't want to use tanks you could probably hook up a clutch to the air compressor so it engages when the driver tells it to and pumps out air in proportion to how fast the car is moving. Another thought would be to make the nozzles on the diffuser adjustable so that during braking and cornering they are pointing to the rear to speed up the airflow and increase downforce, then change back when going down a straight.

If the FIA tried to outlaw the system you could argue that its just movable ballast even though the weight of the air itself, if I've done my calculations correctly, shouldn't be more than 5 kg. As shown below compressed air is fully within the rules.

Technical Regulations

ARTICLE 4: WEIGHT

4.1 Minimum weight:

The weight of the car must not be less than 605 kg at all times during the Event.

4.2 Ballast:

Ballast can be used provided it is secured in such a way that tools are required for its removal. It must be possible to fix seals if deemed necessary by the FIA technical delegate.

4.3 Adding during the race:

With the exception of fuel and compressed gases, no substance may be added to the car during the race. If it becomes necessary to replace any part of the car during the race, the new part must not weigh any more than the original

I'd like to hear what you think. Good or Bad. Hold nothing back.

Totally interesting idea hard to imagine it getting used ...but then again who knows. i wonder how much force would be required to move the air back out front of the aero? How much tanks capable of holding compressed air would add to the overall weight? how much would the movement of air destabilize the car?

how is this (Ballast can be used provided it is secured in such a way that tools are required for its removal) part of the rule interpereted?

all interesting questions???

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Your argument about moveable ballast would not work. All ballast must be secured and non-moveable.

Wouldn't the release of air need to be done at a velocity greater than the incoming air in order to negate it's flow under the car? That would require one helluva forced-air system that would need to consistantly, over the duration of any given straight, blow at a speed greater to the windspeed hitting the car. Also it would possibly add considerable weight to the car. You could use that weight as ballast, but ballast is moved around the car depending on the circuit and this system would be locked into place at one spot on the car.

Your idea about the back of the car seems more do-able, but one could argue that the moveable nozzles are moving aero devices as they serve no function except to affect the aero of the car.

Interesting ideas, but I think it's a moot point. Ferrari are pushing the envelope and will eventually get a ruling against them. All innovation is going by the wayside, but I applaud your innovative spirit!! Long live Colin Chapman!!

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I've had a little more time to think about it and the ballast idea wouldn't work. Too many rules. However, I'm pretty sure the airflow out of the nozzles wouldn't need to be greater than the airflow coming in. If that happened it would come close to eliminating all the airflow and you'd lose most if not all of your downforce, I think. It would be like riding on a mound of air. Whatever difference they could make in airspeed and pressure should do the trick. I should have developed the idea a little more before I posted. Oh well, no harm done. It was this kind of thing that first got me interested in Formula 1 and it upsets me to think of the way the sport is going.

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I've had a little more time to think about it and the ballast idea wouldn't work. Too many rules. However, I'm pretty sure the airflow out of the nozzles wouldn't need to be greater than the airflow coming in. If that happened it would come close to eliminating all the airflow and you'd lose most if not all of your downforce, I think. It would be like riding on a mound of air. Whatever difference they could make in airspeed and pressure should do the trick. I should have developed the idea a little more before I posted. Oh well, no harm done. It was this kind of thing that first got me interested in Formula 1 and it upsets me to think of the way the sport is going.

Ahhh, I get you. I was assuming you wanted to eliminate most, if not all, the airflow from under the car. Reasonable because you really wouldn't need it on the straights anyway; the rear wing would be enough to keep proper traction of the rear tyres....

On your last statement, yes I agree. F1 is too technical in some ways (driver's aids) and too restrictive in others (flexible wings, TMDs).

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I still don't know why we want to reduce downforce on the straights. Rolling resistance? I'd like to know how much of a difference it would make. Normally it's very small, but F1 could be very different of course.

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I still don't know why we want to reduce downforce on the straights.

I think the line of thinking is that downforce = drag, or something.

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When a F1 car is at full speed its generating something like 2.5 times its weight in downforce. With that much weight you need more power to keep it moving or to accelerate it. An example would be to take a car and take it out to the track and top it out. Now take the same car and load it down with twice its weight in lead. Your going to have a hell of a time getting it up to the same speed. If F1 hadn't outlawed movable aero and ground effects we would more that likely be seeing 250 to 300 mph (400 to 480kph) speeds down the straight, if not more. Thats my understanding of it. Correct me if I'm wrong.

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Its more than that, at full speed it generates 2,500 kilos of downforce.

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I still don't know why we want to reduce downforce on the straights. Rolling resistance? I'd like to know how much of a difference it would make. Normally it's very small, but F1 could be very different of course.

The only use for downforce is to corner faster. On the straights you only need enough downforce to keep the tyres in contact with the tarmac. Too much downforce would be akin to this:

When a F1 car is at full speed its generating something like 2.5 times its weight in downforce. With that much weight you need more power to keep it moving or to accelerate it. An example would be to take a car and take it out to the track and top it out. Now take the same car and load it down with twice its weight in lead. Your going to have a hell of a time getting it up to the same speed. If F1 hadn't outlawed movable aero and ground effects we would more that likely be seeing 250 to 300 mph (400 to 480kph) speeds down the straight, if not more. Thats my understanding of it. Correct me if I'm wrong.
I think the line of thinking is that downforce = drag, or something.

In autosports, downforce=low pressure under an airfoil. Drag=low pressure behind a surface facing into the wind. In physics, the definition is 'aerodynamic drag' and is very generic: the resistance caused by a gas to the motion of a solid body moving through it. In autosports, drag describes that resistance as the low pressure behind, say, a tyre, pulling the tyre backwards much like a vacuum. Drag can also be the air hitting the front of that tyre and slowing it down, but that is further refined when talking about an airfoil; in the case of an airfoil, that 'drag' is called deflection and is a part of the downforce equation, not the drag equation. Is anyone confused yet? I am...

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I think the line of thinking is that downforce = drag, or something.

Yeah, that seems to be the kind of idea.

When a F1 car is at full speed its generating something like 2.5 times its weight in downforce. With that much weight you need more power to keep it moving or to accelerate it. An example would be to take a car and take it out to the track and top it out. Now take the same car and load it down with twice its weight in lead. Your going to have a hell of a time getting it up to the same speed. If F1 hadn't outlawed movable aero and ground effects we would more that likely be seeing 250 to 300 mph (400 to 480kph) speeds down the straight, if not more. Thats my understanding of it. Correct me if I'm wrong.

Weight only affects speed via Newton's second law, F=ma. So if your car weighs more, then a given engine will produce lower acceleration. This won't affect your top speed though - it will just take longer to get there, as your acceleration is reduced. Also, note that downforce is not like weight in this context because it doesn't have inertia (its effect on the car's mass is zero) and therefore doesn't appear in F=ma and won't slow the car down.

If you're interested, there are two types of mass: gravitational mass and inertial mass. The first describes how strongly affected by gravity a body is (the gravitational force being proportional to the gravitational mass of the body), and it is exactly analogous to electric charge, which tells us how strongly affected by an electric field an object will be. The latter is totally different. It tells us a body's resistance to being accelerated - if you like, it tells us how hard the object is to push. It is the inertial mass which appears in F=ma. The fact that gravitational mass is always identical in value to the inertial mass is an amazing thing and was one of Einstein's main clues when he invented General Relativity. (The equality of the two values means that being in a gravitational field is exactly the same as being accelerated in a vertical lift or F1 car! In both cases you get pushed down into the ground.)

Adding weight to the car increases both types of mass (as they are always equal) - meaning that the car is harder to accelerate (inertia is greater) but also that it pushes against the ground more, but those two effects are totally separate. Adding downforce doesn't add mass (of any sort as they're always equal) so there is no change to how hard the car will be to accelerate (inertia unchanged) but it will push harder into the ground.

The only use for downforce is to corner faster. On the straights you only need enough downforce to keep the tyres in contact with the tarmac.

Yeah I agree. You don't need very much downforce on a straight (just enough to apply the engine's max power), but I don't think it will slow you down much, unless via rolling resistance.

In autosports, downforce=low pressure under an airfoil. Drag=low pressure behind a surface facing into the wind. In physics, the definition is 'aerodynamic drag' and is very generic: the resistance caused by a gas to the motion of a solid body moving through it. In autosports, drag describes that resistance as the low pressure behind, say, a tyre, pulling the tyre backwards much like a vacuum. Drag can also be the air hitting the front of that tyre and slowing it down, but that is further refined when talking about an airfoil; in the case of an airfoil, that 'drag' is called deflection and is a part of the downforce equation, not the drag equation. Is anyone confused yet? I am...

Yeah that's right and I think the two definitions are pretty much equivalent. ;)

Edit: of course reducing drag would speed you up on a straight and reducing downforce normally reduces drag. But they are not always proportional to one another and I just want to get the distinction clear on the forum, at least for the more technically-minded folks!

Edited by Murray Walker

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There is a price for this amount of downforce. Drag. Redirecting the energy of the airflow to hold a car down creates more resistance for the car to push against. But that's OK. Although drag reduces top speed somewhat, the increase in cornering speeds makes for faster lap times, so some drag is acceptable. Many race cars have drag coefficients of over 1.1, while modern production cars hover around 0.35. The big difference is that race cars have enough horsepower to compensate.

The key is to produce just enough downforce to maximize the average speed around the track. Produce too much downforce and the increased drag will slow the car excessively, too little downforce will hurt cornering speeds. It usually takes some experimenting with wing settings and other components to find the sweet spot where performance is optimized.

http://www.sportcompactcarweb.com/tech/061...dynamics_part_2

This sounds about right. I was wrong in assimilating the downforce to added mass. But as it says, adding more downforce increases the amount of drag, which would make the car harder to accelerate.

So basically in order to change the direction of the air requires energy in the form of drag. To lessen the drag you either need to have very little downforce or a very efficient aero package.

Edited by james

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Yeah that sounds about right! :) I just wanted to get the distinction clear between drag and downforce really. They are not proportional to each other in general, so we shouldn't use the terms interchangeably. Reducing drag would definitely help on the straights like you say.

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FIA steps up illegal floor offensive

Changes ahead of the Spanish Grand Prix

F1's governing body has stepped up its offensive against illegal floor bodywork, according to reports.

The specialist publication Auto Motor und Sport said the FIA's Charlie Whiting has now informed all teams that tests to ensure the rigidity of cars' underbodies will be even stricter at the Spanish Grand Prix next month.

The saga first hit the headlines after the Australian Grand Prix, when teams including Ferrari and BMW Sauber were accused of deliberately circumventing the rules to obtain a performance advantage.

The FIA's subsequent clarification affected the design of most Formula One teams' floors, sources said.

But Auto Motor und Sport contends that Ferrari and BMW's original floor designs passed even the stricter test; motivating the FIA to now quadruple the amount of load applied for the new Barcelona tests.

Toyota's Pascal Vasselon suggests that the move may force some teams to totally re-think their underbody setups, because too stiff a floor is likely to break over the kerbs.

"Many teams will have to raise their cars quite a lot," he said, "but (raising a car by) only a millimetre can mean two per cent less downforce."

Source GMM

CAPSIS International

http://www.totalf1.com/view-article.php?newsid=203363

What will happend now?

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I doubt the compressed air idea would work as described. Besides any sort of active aerodynamics like this are strictly outlawed.

Bleeding pressurised air over aero surfaces is a well known practice, Aircraft often blow air through slots on large wings\flaps to prevent the device stalling. In some respects the use of the exhausts blowing under the rear wing are a similar solution (or through the diffuser if you go back to the eighties\nineties)

Drag and downforce are linked, downforce squares with speed, while drag cubes.

Thus at higher speed drag increases to the point where to add any top speed would require huge increases in HP. If you can reduce drag you can get a higher top speed, but as we've already seen we still need downforce to get around corners. At high speed downforce is doing nothing for the car, thus if you can reduce downforce, then you also reduce drag, which will improve top speed. This is why every team use clever flexible wings that flatten off at high speed, thus they give downforce in the corners (slower compared to the straights), but give lower drag on the straights for high top speed.

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A novel idea. Somewhere in the back of my mind I recall that this compressed air idea, or a variation thereof, has been used on powerboats, to separate the hull from the water. I must think on this some more.

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"Many teams will have to raise their cars quite a lot," he said, "but (raising a car by) only a millimetre can mean two per cent less downforce."

Yeah, but that doesn't matter much on the straights.

I doubt the compressed air idea would work as described. Besides any sort of active aerodynamics like this are strictly outlawed.

Bleeding pressurised air over aero surfaces is a well known practice, Aircraft often blow air through slots on large wings\flaps to prevent the device stalling. In some respects the use of the exhausts blowing under the rear wing are a similar solution (or through the diffuser if you go back to the eighties\nineties)

Drag and downforce are linked, downforce squares with speed, while drag cubes.

Thus at higher speed drag increases to the point where to add any top speed would require huge increases in HP. If you can reduce drag you can get a higher top speed, but as we've already seen we still need downforce to get around corners. At high speed downforce is doing nothing for the car, thus if you can reduce downforce, then you also reduce drag, which will improve top speed. This is why every team use clever flexible wings that flatten off at high speed, thus they give downforce in the corners (slower compared to the straights), but give lower drag on the straights for high top speed.

Interesting post. But I've never heard this before. Are you sure? Normally people say that they both vary as speed squared (when measured in units of force, as opposed to power). This is itself a huge simplification, because the drag coefficient (the "constant" of proportionality in these relationships) actually varies with speed too! You might like to read this physics world article on the aerodynamics of football - it shows an example of the drag coefficient varying with speed.

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Well I hope this time that it works as desired, and anyone using illegall flexing floors get caught out

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Well I hope this time that it works as desired, and anyone using illegall flexing floors get caught out

Except Renault :whistling:

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Including Renault. Rule Breaking = bad whoever does it (including McLaren) :P

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Yeah, but that doesn't matter much on the straights.

Interesting post. But I've never heard this before. Are you sure? Normally people say that they both vary as speed squared (when measured in units of force, as opposed to power). This is itself a huge simplification, because the drag coefficient (the "constant" of proportionality in these relationships) actually varies with speed too! You might like to read this physics world article on the aerodynamics of football - it shows an example of the drag coefficient varying with speed.

I liked the article. One thing should be pointed out, I think: the drag coefficient of a football varies only when the air is made turbulent from increased velocity, right? F1 cars, unlike footballs, are designed to smooth out the turbulent air.

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Interesting post. But I've never heard this before. Are you sure? Normally people say that they both vary as speed squared (when measured in units of force, as opposed to power). This is itself a huge simplification, because the drag coefficient (the "constant" of proportionality in these relationships) actually varies with speed too! You might like to read this physics world article on the aerodynamics of football - it shows an example of the drag coefficient varying with speed.

This may be an oversimplification, and I haven't read the article yet (though I will), and I will generally bow to Mike's knowledge when it comes to aero, but ... My understanding is that the goal is to maximize the increase in downforce while minimizing (key word) the increase in drag. IIRC, drag will always increase at a rate greater than or equal to the increase in downforce. Hence, "a new rule designed to reduce downforce by 20%" -> "The team spent millions of dollars/pounds/euros/spacebucks in the wind tunnel over the off-season, and the engineers feel that they've regained 15% of that downforce, while reducing the drag by 5%, leading to a net decrease in lap times."

I'm all for innovation, but F1 is moving more and more towards irrelevancy (yes, I've said that before) ... Something truly innovative is only allowed if enough teams thought of it at the same time, while the rules-makers scramble to keep up. 19k rpm 2.6-litre engines? Yeah, that's useful. 15% improvement in downforce? That'll help my daily commute how? Yet we keep hearing all of this "green" crap, F1 "needs to be more responsible" ... Okay, slippery slope. This is leading into a rant for a different subject.

I'll sum up what I was trying to say with this: BAN THE GREEBLIES!!!!111!one!

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