Allow flexible wings especially on ground effect cars

[Taxi645]

A case for (passively) flexible wings.

In this age where a lot of pfuff is made over efficiency with these hybrid engines is rather silly to drag so much resistance through the air (with speed, drag goes up by the power of 3 per unit of time, power of 2 per distance). The new generation of cars have plenty of downforce at speed but lack grip at slower speed. One solution could cheaply and elegantly solve part of all these problems in one go:


Allow (passively) flexible front and rear wings.

The advantages of this would be:

• Less drag, means less fuel means lighter car and more sustainable.
• Less downforce at high speed reduces porpoising, which in turn allows softer suspension which allows more grip at slower speeds.
• You don’t need to test the flex because it is allowed, desired even.
• Flexible wings won’t break.

In a high tech environment like F1 it is quite odd that we have fixed wings when their requirements in the corners (high downforce) and straights (low drag) is completely different. Bending wings would allow faster lap times and better efficiency which is both desirable. One does need to ensure by regulation that the wings bend in a linear manner otherwise dangerous handling characteristics would occur.



Just let them fix the front of the aero surfaces and let the rear of the surfaces flex away.

[crmalcolm]

A case for why flexible wings should not be permitted (courtesy of racefans.net):

During testing at Barcelona in February 1999, Johnny Herbert’s Stewart-Ford crashed at 190 mph.

Approaching turn one the rear wing failed, turning the car sharply to the left and directly into the barrier. The car repeatedly hit the barrier as it decelerated. Compatriot Damon Hill saw the shunt and said it was:

A monster accident – the biggest shunt I have ever seen. It is very worrying. People are experimenting with bendy rear wings. Lots of teams have been having problems.

Those teams included Ferrari – Michael Schumacher had experienced a rear wing collapse. So had Benetton and Sauber, and two such failures had occured on BARs and Prosts. Hill added:

The FIA ought to be concerned about that. Front and rear wing failures are two of the worst things that can happen, because they only occur at high speed. That’s how Roland Ratzenberger was killed at Imola in 1994. Flexible wings can be dangerous. On top of that, once all of the teams have got them, it will cancel out any advantage, but the danger will still be there.

At the first race of the season in Melbourne photographic evidence strongly suggested that at least Ferrari and Sauber were running flexible rear wings that tilted backwards at high speed to reduce drag.

During the race the rear wing failed on Jacques Villeneuve’s BAR, causing a crash. Then Sauber’s technical director Leo Ress admitted:

I saw something similar on some of the cars last season, so when we designed the new car, the rear wing was deliberately designed to flex a little bit.


In short - the FIA has already seen the effects of wing failures attributed to permitting flex, and so for safety reasons they are banned.

[Mike Harte]

I have no opinion on whether they should or shouldn't be permitted, but in response to CRM about failures, I believe that materials and knowledge about flexing wings has moved on hugely since Herbert's crash.

One only has to look at the aeronautical industry to appreciate that large aircraft are all created with wings that flex by huge amounts and under possibly far greater strain than a F1 car, all without failures, certainly in the short term. It is possible that certain defects do show up over the longer term, but that would be after many hours of flying.

[Taxi645]

Yes, Mike completely true. There also is a difference between experimental (even illegal) flexing wings and flexing wings that are allowed, pre-scripted and controlled by the FIA in a way that makes them save. A wing would still be tested for strength but not for stiffness (except for linear flex behaviour).

So the requirements could be:

- Needs to fulfil certain strict strength and fatigue criteria.
- Would need to flex within a linear threshold (to avoid optimizations that favour performance but make handling at high speed less predictable and dangerous).
- Passive, so based on the wings mechanical properties and the aero load applied on them. No artificial cockpit button pushery.

At the same time fuel flow would be restricted to keep top speeds in check.

Say it saves 10% of fuel, than it makes the cars 11kg lighter at the start of the race and still 5.5kg half way.


To not compromise acceleration, this reduction in power would best go along with the lighter cars from 2026 onwards. Hopefully by then we don't need DRS any more which would not be very effective with these flexing wings.

[crmalcolm]

Originally Posted by Mike Harte

I have no opinion on whether they should or shouldn't be permitted, but in response to CRM about failures, I believe that materials and knowledge about flexing wings has moved on hugely since Herbert's crash.

Mike - totally agree, the knowledge has moved on significantly and there is also a lot more incorporation of flex in modern wing design (particularly in the aeronautical industry).

But, that said - an aeronautical wing is designed to allow a certain amount of flex from the outset and within certain safety parameters. An aircraft designer is not incentivised in any way to push the boundaries of safety for a performance advantage. Can we assume the same from F1 car designers?

IMO - it opens up an area where safety may be compromised, so why even look in that area?

[crmalcolm]

Originally Posted by Taxi645

There also is a difference between experimental (even illegal) flexing wings and flexing wings that are allowed, pre-scripted and controlled by the FIA in a way that makes them save. A wing would still be tested for strength but not for stiffness.

So the requirements could be:

- Needs to fulfil certain strict strength and fatigue criteria.
- Would need to flex within a linear threshold (to avoid optimizations that favour performance but make handling at high speed less predictable and dangerous).

This reads like the situation we currently have. Wherever you set that boundary, the teams will push the limits of it.

Considering we haven't even seen the current cars in a race setting, and just have minimal testing evidence to go on - are we creating a problem that doesn't really exist?

[Taxi645]

Originally Posted by crmalcolm

Mike - totally agree, the knowledge has moved on significantly and there is also a lot more incorporation of flex in modern wing design (particularly in the aeronautical industry).

But, that said - an aeronautical wing is designed to allow a certain amount of flex from the outset and within certain safety parameters.

That's exactly what I'm proposing; designed to allow a certain amount of flex from the outset and within certain safety parameters.

An aircraft designer is not incentivised in any way to push the boundaries of safety for a performance advantage. Can we assume the same from F1 car designers?

On the contrary, aircraft designers go to extreme length's to optimize the performance/economy of the aircraft. Authorities like the FAA and EASA make sure they meet the required safety standards. This would be the same and what the FIA has always done.

IMO - it opens up an area where safety may be compromised, so why even look in that area?

The safest racing car is one that goes with the speed of a shopping cart and is remotely controlled... We all accept a certain level of risk in all aspects of F1 car regulations and design. With this it would be the same, first and foremost it needs to be as safe as reasonably possible. If that can be guaranteed, why not?

[Taxi645]

Originally Posted by crmalcolm

This reads like the situation we currently have. Wherever you set that boundary, the teams will push the limits of it.

Yes, so you make sure the boundary limit they would push up against is safe.

Considering we haven't even seen the current cars in a race setting, and just have minimal testing evidence to go on - are we creating a problem that doesn't really exist?

I've proposed flexing wings a long time ago. In my view it make sense then (under the listed conditions) and it makes even more sense with the ground effect car (for the reasons mentioned).

It's not really about solving an unacceptable problem, it's about doing things in a smarter way. Dragging barn doors through the air at 200mph is not worthy of F1 @2022 in my view. If I'm not mistaken the FIA was looking into introducing adjustable wings a few months back, but I couldn't find it. They proposed button activated adjustable wings if I remember correctly, which I don't like much because it is too gimmicky to me and potentially dangerous.

The reduction in porpoising with DRS open indicates that reduced aero load from the wings at high speed would be beneficial to reducing the porpoising effect. The cars gets pushed less hard to the ground at high speed so the stall of the air underneath the car because of the height under the car become to narrow to pass at speed will be not as likely.

[Mike Harte]

Originally Posted by crmalcolm

Mike - totally agree, the knowledge has moved on significantly and there is also a lot more incorporation of flex in modern wing design (particularly in the aeronautical industry).

But, that said - an aeronautical wing is designed to allow a certain amount of flex from the outset and within certain safety parameters. An aircraft designer is not incentivised in any way to push the boundaries of safety for a performance advantage. Can we assume the same from F1 car designers?

IMO - it opens up an area where safety may be compromised, so why even look in that area?

With regards to what an aircraft manufacturer will or won't do, I would suggest that you ask those grieving for lost ones in the two fairly recent Boeing 737 Max crashes. It is now known that Boeing hoodwinked the authorities to a) speed up production and b) to save money.

And this is why the FIA insist that comprehensive crash tests are carried out on all new F1 designs - quite rightly. The same could or should be applied to a flexing wing.

[crmalcolm]

Originally Posted by Mike Harte

With regards to what an aircraft manufacturer will or won't do, I would suggest that you ask those grieving for lost ones in the two fairly recent Boeing 737 Max crashes. It is now known that Boeing hoodwinked the authorities to a) speed up production and b) to save money.

And this is why the FIA insist that comprehensive crash tests are carried out on all new F1 designs - quite rightly. The same could or should be applied to a flexing wing.

Notwithstanding that those accidents have not been attributed to aerodynamic design - IMO they serve as an argument for why flexing of wings in F1 should not be permitted on safety grounds. The aircraft were released into service and approved by many regulatory authorities - can the same be assured of F1 car release authority?

[Mike Harte]

Originally Posted by crmalcolm

Notwithstanding that those accidents have not been attributed to aerodynamic design - IMO they serve as an argument for why flexing of wings in F1 should not be permitted on safety grounds. The aircraft were released into service and approved by many regulatory authorities - can the same be assured of F1 car release authority?

I don't want to start an argument about what happened with Boeing, but suffice it to say that it was certified by the FAA who, stupidly, delegated most of the certification to Boeing itself, as the reports have attested to. It was then certified by other authorities who piggy-backed on the FAA certification without further investigations.

The FAA has been heavily criticised for their part in the matter and their lack of true oversight of the certification process.

[crmalcolm]

Originally Posted by Mike Harte

I don't want to start an argument about what happened with Boeing, but suffice it to say that it was certified by the FAA who, stupidly, delegated most of the certification to Boeing itself, as the reports have attested to. It was then certified by other authorities who piggy-backed on the FAA certification without further investigations.

The FAA has been heavily criticised for their part in the matter and their lack of true oversight of the certification process.

Agreed - I have no intention of this dragging down into a battle. I'll leave my position as - 'I think the safety implications of allowing a flexible wing to be used make it an option that should not be considered. We have had minimal testing under the current set of regulations, and so it is too early to even start looking for problems'.


**Apologies to all if it seemed like bickering from the start**

[Mike Harte]

Originally Posted by crmalcolm

Agreed - I have no intention of this dragging down into a battle. I'll leave my position as - 'I think the safety implications of allowing a flexible wing to be used make it an option that should not be considered. We have had minimal testing under the current set of regulations, and so it is too early to even start looking for problems'.


**Apologies to all if it seemed like bickering from the start**

[chillibowl]

under the budget cap and their desire to prevent engaging down paths that lead to massive amounts of new spending, how would a flexible wing solution work?

for sure it could be an option instead of the ground effects path but given they have just decided to go back down this path they are likely not going to change directions now are they?

FOM has a lot riding on this current configuration working...if this path fails then they may have little choice but to let the teams dictate the rules going forward.

[Taxi645]

Originally Posted by crmalcolm

Agreed - I have no intention of this dragging down into a battle. I'll leave my position as - 'I think the safety implications of allowing a flexible wing to be used make it an option that should not be considered. We have had minimal testing under the current set of regulations, and so it is too early to even start looking for problems'.

**Apologies to all if it seemed like bickering from the start**

Originally Posted by chillibowl

under the budget cap and their desire to prevent engaging down paths that lead to massive amounts of new spending, how would a flexible wing solution work?

Simple, there is a budget cap, stay within it.

for sure it could be an option instead of the ground effects path but given they have just decided to go back down this path they are likely not going to change directions now are they?

To be clear it is not meant as an alternative to the ground effect path. It is something that comes on top of and works better in conjunction with ground effect. I'm not saying they should do it next year. I think it would be a good idea for the next mayor rule change in 2026. If they want to do it before than it's fine by me.

[Richard C]

I generally think this is a solution looking for a problem. To the initial points

Originally Posted by Taxi645

Less drag, means less fuel means lighter car and more sustainable.

I say this is a tenuous case. Is the solution worth the squeeze? See the comments below.

Originally Posted by Taxi645

Less downforce at high speed reduces porpoising, which in turn allows softer suspension which allows more grip at slower speeds.

Speculation. Please point to an expert in this space that is arguing this a solution.

Originally Posted by Taxi645

You don’t need to test the flex because it is allowed, desired even.

Define "passive" and "flexible" for me. What are the limits on using these concepts? No "tests" means full freedom? This is opening a huge can of worms and potential unintended uses. I would love to see some sample regulations on this. See comments below.

Originally Posted by Taxi645

Flexible wings won’t break.

Ok, we know this is not true. Everything can break.

I am not against movable aero. Active aero (beyond DRS which is active aero) have some benefits. But they would have to have some strict controls (I have posted a few times on this). I am doubtful that the problems you list are real, but lets say they are true. Then those are likely be more predictably and cheaply controlled via active aero vs. some passive situation.

Lets consider F1 suspension. F1 suspension is pretty complex because rules require it to be a mechanical system. And even when teams tried complex mechanical solutions (such as inerters) they are eventually banned. If you put teams into a box that takes away active control, they will create more and more complex solutions such as inerters for suspension and aero vortexes to try to seal the edges of the underbody because you can't use skirts.

Take Theo Jansen's sculptures. I would say these are passive aero devices. Yes, they are more than just flexible, because they would have hinged joints and other classic mechanical items. But the point stands that you can have VERY complex devices that are passive.

https://www.youtube.com/watch?v=LewVEF2B_pM

Next, lets look at flexible material. You might think the following video supports your assertion. The video is very cool and shows there are real world solutions for this (typically in micro machine use cases). But my point is the video is meant to show the level of ingenuity and true usefulness than can be created by use of purely flexible mechanism.

https://www.youtube.com/watch?v=97t7Xj_iBv0

Imagine combining both concepts together. No doubt very trick things could be created. And engineers will go in directions other than you suggest. But in the end, it will be again like making complex mechanical watches in a world in which cheap quartz watches do the job of telling the time much better. So if the problems you list are true, which I don't believe they are, but lets say they are. I would argue that passive solutions are a Pandora's box for complex, costly and esoteric solutions that could be done in a more controlled and cheaper way via active items that are probably much easier to limit from a regulations perspective. And if the problems are not real, the solutions are moot.

Richard

[Taxi645]

Originally Posted by Richard Casto

I say this is a tenuous case. Is the solution worth the squeeze? See the comments below.

I don't think it is tenuous at all, for four reasons:

1 The cars are too heavy. Every single driver is saying they like the new cars, but feel they are too heavy. Rigid wings means high drag means that you have to burn and carry a lot of fuel to make it to the end of the race. Even if they could save only 10kg of fuel at the start that would be a worthwhile part of reversing the weight increasing trend.

2 Sustainability A lot of pfuff is made about the efficiency of the current generation power unit, while at the same time the aerodynamics are a blunt instrument that lead to a lot of drag and thus fuel use.

3 Road relevance F1 have a drag coefficient close to 5x worse than the best street cars at the moment. Sure street cars don't create (these levels of) downforce, but still.

4 Future battery fuelled motorsport. In the end motorsport will become electric. The problem is (which is clearly visible in Formula E), batteries have a lot lower energy density than fuel and unlike fuel don't burn off all of their weight during the race. To allow top level electric motorsport the aero needs to get more efficient long term.

Speculation. Please point to an expert in this space that is arguing this a solution.

So we are now only allowed to discus expert opinion even if we can give common sense a shot?

The porpoising problem with increased speed is caused by the self-reinforcing effect of the downforce getting stronger the closer the car gets to the ground before suddenly inverting because of the stalling of the air when it gets too close and the cycles starts over again. The engineers want the cars to be as close to the ground as possible before this stall occurs. There they need pretty stiff suspension to keep the cars as close as possible in that aero sweat spot for as much of the lap as possible. If you allow flexible top wings their downforce will not increase by the power of two with speed but less so. So you are weakening a component (exponentially increasing downforce with speed) that helps to create this self-reinforcing and then inverting effect. That means, you won't have to set up the cars as hard to avoid it getting too close to the ground at high speed causing the air to stall and the porpoising cycles to start.

It would not be a paradigm shift, but it would help.

Define "passive" and "flexible" for me. What are the limits on using these concepts? No "tests" means full freedom? This is opening a huge can of worms and potential unintended uses. I would love to see some sample regulations on this. See comments below.

I have already addressed this in an earlier post:

- Needs to fulfil certain strict strength and fatigue criteria.
- Would need to flex within a linear threshold (to avoid optimizations that favour performance but make handling at high speed less predictable and dangerous).
- Passive, so based on the wings mechanical properties and the aero load applied on them. No artificial cockpit button pushery.

What can of worms and potential unintended uses do you foresee?

Ok, we know this is not true. Everything can break.

True and I should not have put it like that, but generally flexible stuff don't not break as easily as brittle stuff.

I am not against movable aero. Active aero (beyond DRS which is active aero) have some benefits. But they would have to have some strict controls (I have posted a few times on this). I am doubtful that the problems you list are real, but lets say they are true. Then those are likely be more predictably and cheaply controlled via active aero vs. some passive situation.

Lets consider F1 suspension. F1 suspension is pretty complex because rules require it to be a mechanical system. And even when teams tried complex mechanical solutions (such as inerters) they are eventually banned. If you put teams into a box that takes away active control, they will create more and more complex solutions such as inerters for suspension and aero vortexes to try to seal the edges of the underbody because you can't use skirts.

Take Theo Jansen's sculptures. I would say these are passive aero devices. Yes, they are more than just flexible, because they would have hinged joints and other classic mechanical items. But the point stands that you can have VERY complex devices that are passive.

https://www.youtube.com/watch?v=LewVEF2B_pM

Next, lets look at flexible material. You might think the following video supports your assertion. The video is very cool and shows there are real world solutions for this (typically in micro machine use cases). But my point is the video is meant to show the level of ingenuity and true usefulness than can be created by use of purely flexible mechanism.

https://www.youtube.com/watch?v=97t7Xj_iBv0

Imagine combining both concepts together. No doubt very trick things could be created. And engineers will go in directions other than you suggest. But in the end, it will be again like making complex mechanical watches in a world in which cheap quartz watches do the job of telling the time much better. So if the problems you list are true, which I don't believe they are, but lets say they are. I would argue that passive solutions are a Pandora's box for complex, costly and esoteric solutions that could be done in a more controlled and cheaper way via active items that are probably much easier to limit from a regulations perspective. And if the problems are not real, the solutions are moot.

Richard

Yes, definitely engineers will try to find solutions to optimize performance. That's their job. It becomes a problem if that leads to undesirable results. There are already two mechanisms in place to prevent that.

1 Teams can inform with the FIA whether certain interpretations of the rules are allowed (to prevent them burning cash on stuff that turns out illegal and to prevent rival teams to introduce or keep running certain solutions).
2 The FIA can ban interpretations that are not in the spirit of the rules or considered dangerous.


That said, I'm not really against active aero, as long as it not cockpit or remotely controlled. For the fans than it is no longer clear what you are actually looking at. Also I much prefer the more analogue/linier character of passive aero in stead of the binary effect active would have.




To me it is a bit the same as with ground effect. A long time it was banned and ignored by F1 because events in the past. Through scientific method they have devised a way to reintroduce it in a safe and beneficiary manner (the re-emerging porpoising problem being a drawback that will be fixed I expect). I expect the same for moveable aero. Through scientific method they will devise the right criteria and tests to allow it in a safe and beneficiary manner.

[Richard C]

Originally Posted by Taxi645

I don't think it is tenuous at all, for four reasons:

Again, I see flexible passive aero as poor solutions for those problems.

Originally Posted by Taxi645

So we are now only allowed to discus expert opinion even if we can give common sense a shot?

Explain how "common sense" applies to complex aerodynamics? We can talk about whatever we want. But if you make extraordinary claims, be prepared to provide extraordinary evidence.

In my reply I talked about active aero likely being a better than passive aero. I kept the topic to "aero", but I agree with what Russell and James Key at McLaren say below...

https://www.motorsport.com/f1/news/r...ution/8572024/

Basically the root problem is downforce changing ride height and creating an oscillation then active suspension would be an excellent answer. When I first saw the cars doing this, it took me back to my controls engineering class from years ago. In that if the system was modelled and appropriate feedback was applied it could be easily solved. Some type of active system (which would include an active feedback loop) is best. With ride height control being the obvious solution. But a passive aero solution is two degrees removed from an optimal solution. (aero as a method to adjust ride height and passive vs. active)

Originally Posted by Taxi645

I have already addressed this in an earlier post:

Apologies. Yes, you have agreed in your response to Mike that making the wings flexible would NOT obviate the need for potentially complex tests.

Originally Posted by Taxi645

What can of worms and potential unintended uses do you foresee?

Is that not the problem? You see a problem (or problems). You propose a solution to fix those problems. You, me or whoever might consider this solution would need to put just as much thought into what else the teams might do with the new area in the regulations.

Think of the times people have introduced non-native species to solve a problem and then found it created a new one. In the south of the US we have an invasive Japanese plant named "Kudzu". It was brought into the US a long time ago thinking it would be a nice thing to look at, provide feed for animals and help with erosion. The stuff spreads like crazy and is a menace. "The best-laid plans of mice and men often go awry"

But to answer your question (and assuming you are looking to restrict this to just the front wings), the teams will focus heavily on any way they can utilize front wing flexibility to influence (or support) overall aero concepts on the car. I showed examples in which you can create complex mechanism that only consist of flexible components. Imagine binary on/off switches that are buried inside of wings driven by combinations of mass driven levers or air pressure differentials to then effectively create mechanical computers that try to replicate active aero solutions via complex and costly mechanical computers buried in the front wings.

You might say... Well, that is not what we want them to do! Teams will do it, then this starts a cycle of ever more complex technical regulations with teams again devoting budget to work around. All of this buried in components that are easily damaged during a race weekend. It would be like throwing money into a fire.

I am not saying we can't ever introduce new concepts, but we have to be careful. The current porposing issue is one for example. I am not saying to stop the underbody aero. I am just saying that the best F1 teams in the world showed up and had unexpected issues. Teams can be caught out. Regulators can be caught out.

Originally Posted by Taxi645

True and I should not have put it like that, but generally flexible stuff don't not break as easily as brittle stuff.

That is a general statement, but you made an absolute argument. And does anyone believe that we would really see wings be more robust just because they have some flexible elements. Maybe marginally so?

Originally Posted by Taxi645

Yes, definitely engineers will try to find solutions to optimize performance. That's their job. It becomes a problem if that leads to undesirable results. There are already two mechanisms in place to prevent that.

1 Teams can inform with the FIA whether certain interpretations of the rules are allowed (to prevent them burning cash on stuff that turns out illegal and to prevent rival teams to introduce or keep running certain solutions).
2 The FIA can ban interpretations that are not in the spirit of the rules or considered dangerous.

See my comments above. Passive solutions would be hard to regulate. I think active systems (be it aero or suspension) would be easier if you set a very specific and tight box. I know this is off topic for this thread but a way to keep the box tight is...

1. Standard ECO for any active solution (similar to what is done with the power unit)
2. Fixed number of sensor channels
3. Fixed number of control channels
4. Potentially homologate the sensors and actuators
5. Some rule language to try to address how the actuators are applied to the active components

#5 would be the area in which there would be some active rule revisions as teams find holes. But overall, the teams should find that money spent on creative software would provide much more bang for the buck to try to also patch on complex/costly mechanical solutions. My point is... the regulations should be framed to dissuade teams (due to significant dimension returns) from spending money to find and exploit loopholes in the active solutions. In a pre-cost capped world, if there is ANY loophole, teams could maybe devote resources to it. But now, if the benefits are not worth the spend, then they will look elsewhere to spend their money.

Originally Posted by Taxi645

That said, I'm not really against active aero, as long as it not cockpit or remotely controlled. For the fans than it is no longer clear what you are actually looking at. Also I much prefer the more analogue/linier character of passive aero in stead of the binary effect active would have.

Agree on not allowing remote operation (see my comments above about standard ECU and local sensors only). I have no opinion regarding cockpit control. Actually, if you let drivers select engine modes and other things, why not also allow them to select aero modes as well.

I am not sure about the analogue/linear comment of passive vs. active. Just because active might be computer controlled does not mean the action would need to be binary. It can be as fluid or graceful as anything.

But lets say you don't like the potential for binary actions. Such as the on/off nature of DRS today. As I point out above, imagine a passive mechanical computer that operates only via flexible components. It could be constructed to create just as dynamic on/off actions as DRS. All via an analogue computer.

Originally Posted by Taxi645

To me it is a bit the same as with ground effect. A long time it was banned and ignored by F1 because events in the past. Through scientific method they have devised a way to reintroduce it in a safe and beneficiary manner (the re-emerging porpoising problem being a drawback that will be fixed I expect). I expect the same for moveable aero. Through scientific method they will devise the right criteria and tests to allow it in a safe and beneficiary manner.

I agree with you about the potential to bring back banned concepts, but in a controlled way.

Richard

[Richard C]

Taxi645,

I think I have been a bit of a strong contrarian to your threads in which you toss out ideas. I feel bad about that, because you are putting this ideas out there and it's easy for someone like me to say "no!". You have spurred me to create a thread for active suspension. So you or others can beat me up. I may post that later today.



Richard

[Taxi645]

Originally Posted by Richard Casto

Taxi645,

I think I have been a bit of a strong contrarian to your threads in which you toss out ideas. I feel bad about that, because you are putting this ideas out there and it's easy for someone like me to say "no!". You have spurred me to create a thread for active suspension. So you or others can beat me up. I may post that later today.



Richard

[Taxi645]

What I'm thinking of is the type of aerofoil that Red-Bull was accusing Mercedes of using last year. So fixed at the leading edge but flexible at the end to allow it to bend away with increased speed to bleed off drag and downforce at those high speeds.

One could consider a camera monitoring system for it. So in the regulations lay-out of the wings and camera's would be such that the moveable aerofoils will always be visible to the camera's in a way that the deflection can be monitored in a well calibrated optical way. Allow flex within a linear threshold (so optically measured) and put this on top of the already mentioned required strength and fatigue tests and I think you could possible reach an acceptable amount certainty in regards to:

1 Breaking strength
2 Safe handling characteristics
3 No amount of trickery.

A further advantage would be that teams will need less sets of wings. In stead of multiple sets depending on the track, they would only need two for instance or perhaps even just a single set. Because the flexibility of the wings allows it to be suitable for a lot of different type of tracks with way different average speed and downforce requirements (think Monaco vs. Monza).

[wnut]

^^^ Nice theory Taxi, problem is that they would have 12 different flexible wings for different circuits and another 6 under construction to try out separate characteristics. How many cycles would you test a flexible wing for? A rigidity test provides reasonably simple determination of the wings fitness for purpose, would be way more difficult on a flexible structure!

This proposal is a complex solution.

[Taxi645]

Originally Posted by wnut

^^^ Nice theory Taxi, problem is that they would have 12 different flexible wings for different circuits and another 6 under construction to try out separate characteristics.

I think the more likely scenario is less wings. Currently you want a maximum downforce wing for a track like Monaco, a minimum downforce wing for Monza and then you have the tracks in between and new developments you do during the season. A flexible wing adjusts it's downforce level according to the speed in each corner and on the straight. So a slow corner means maximum downforce and a fast one or straight means less downforce.

With ground effect we already have plenty of downforce in fast corners, from the bottom of the car. The reduced downforce at speed of the flexible wings is not a problem for the current generation cars. It will make them faster over the whole of the lap, more efficient and helps a little with allowing softer suspension for the slow stuff.

How many cycles would you test a flexible wing for? A rigidity test provides reasonably simple determination of the wings fitness for purpose, would be way more difficult on a flexible structure!

Say the average track has 10 acceleration/de acceleration cycles (not every corner means braking or a significant change in speed), a race weekend has 150 laps (give or take a few) and you have 23 events. That gives a little below 35.000 cycles for one wing or 17.500 for two. Apply to that the applicable safety margin and you know for how many cycles you need to test it for.

Carbon bit's that flex and do many cycles are very common. Think bike frames or windsurfing masts, aircraft wings etc. I don't see this as a problem.

This proposal is a complex solution.

It's complex yes, but so is ground effect aerodynamics (as we can still see with the porpoising issue). After everyone got convinced it was the best way forward, investments were made to introduce it in a safe and beneficiary manner. This would be the same.

[crmalcolm]

Originally Posted by Taxi645

The reduced downforce at speed of the flexible wings is not a problem for the current generation cars. It will make them faster over the whole of the lap, more efficient and helps a little with allowing softer suspension for the slow stuff.

The efficiency is far more complicated than that, and one that is not answered by a flexible wing.
Consider it in this manner:

A low-drag wing that is fixed has a consistent amount of drag. The amount of energy required to overcome this drag is also fixed for any given speed, and can be traced (relatively) easily.
In your flexible wing example, what is causing it to flex? The higher speed of the car is causing the wing to flex in response to the aero load being placed upon it. To make it flex at higher speed, the car has to overcome the higher drag of the wing and force it down.

To demonstrate this, imagine the following characteristics of the flexible wing:

In the stationary position, the wing has a certain drag coefficient.
In order to reduce the drag a force is required. This force is only generated by expending energy. The faster the car is going, the more energy is spent forcing the wing down, counter-acting the reduced drag gains.

But what about the controversy over flexible wings in 2021?
These were only considered as a desirable by the teams at certain tracks, and under certain conditions. They were not a fix-all across all tracks. There were careful calculations based on the peak speeds reached, with a 'tip-over' point at which the structure of the wing would flex. This was not a consistent slope of flex, but a certain point at which this happened. Allowing teams to include flex as a default means that the designers will come up with track-specific wings that have a 'tip-over' point suitable for that circuit alone.

Originally Posted by Taxi645

Say the average track has 10 acceleration/de acceleration cycles (not every corner means braking or a significant change in speed), a race weekend has 150 laps (give or take a few) and you have 23 events. That gives a little below 35.000 cycles for one wing or 17.500 for two. Apply to that the applicable safety margin and you know for how many cycles you need to test it for.

Again - a much more complicated situation to the one you outline here.
To fully apply a safety margin, you need to replicate the full usage of the wing's life-cycle. It is not just about how many times it goes through a deceleration, it is also about the sustained pressure at speed that is applied to the material. You need to put a wing in a wind tunnel, and simulate the full life of the wing to achieve what you are suggesting - and we are trying to reduce the time spent in wind tunnels surely?

Originally Posted by Taxi645

It's complex yes, but so is ground effect aerodynamics (as we can still see with the porpoising issue). After everyone got convinced it was the best way forward, investments were made to introduce it in a safe and beneficiary manner. This would be the same.

So having gone through the introduction of the current aerodynamics in a safe and beneficiary manner, why do it all again for a problem that doesn't currently exist?

[Taxi645]

Originally Posted by crmalcolm

The efficiency is far more complicated than that, and one that is not answered by a flexible wing.
Consider it in this manner:

A low-drag wing that is fixed has a consistent amount of drag. The amount of energy required to overcome this drag is also fixed for any given speed, and can be traced (relatively) easily.
In your flexible wing example, what is causing it to flex? The higher speed of the car is causing the wing to flex in response to the aero load being placed upon it. To make it flex at higher speed, the car has to overcome the higher drag of the wing and force it down.

To demonstrate this, imagine the following characteristics of the flexible wing:

In the stationary position, the wing has a certain drag coefficient.
In order to reduce the drag a force is required. This force is only generated by expending energy. The faster the car is going, the more energy is spent forcing the wing down, counter-acting the reduced drag gains.

Almost completely right except for the last bit. For two reasons:

1 This forcing down is happening now with rigid wings as well, but with more force (because not flexing away and thus causing more downforce).
2 More importantly, the actually work (force x distance) being done is on pulling the air up and along. This is what is causing the drag, where the actually work is being done and for which the power (work/time) to overcome the drag is needed. The amount of work done on the wing itself is neglect-able (it's a very light part moved very little)

So with a flexible wing you try to maximize the average downforce through all types of corners at an as low as possible drag level. Imagine it being a Monza type wing at speed, but more like a Monaco type wing in slow corners.

That's why F1 engineers are so desperate to use it at any change they feel they can get away with. For what other reason would they pursue such folly?

But what about the controversy over flexible wings in 2021?
These were only considered as a desirable by the teams at certain tracks, and under certain conditions. They were not a fix-all across all tracks. There were careful calculations based on the peak speeds reached, with a 'tip-over' point at which the structure of the wing would flex. This was not a consistent slope of flex, but a certain point at which this happened. Allowing teams to include flex as a default means that the designers will come up with track-specific wings that have a 'tip-over' point suitable for that circuit alone.

Yes, agreed. This circuit tuned tip-over point would indeed be costly and undesirable in my view. Therefore you would have the camera monitoring (and certain basic tests), as described earlier, to make sure their flex characteristics would indeed be linear.

Again - a much more complicated situation to the one you outline here.
To fully apply a safety margin, you need to replicate the full usage of the wing's life-cycle. It is not just about how many times it goes through a deceleration, it is also about the sustained pressure at speed that is applied to the material. You need to put a wing in a wind tunnel, and simulate the full life of the wing to achieve what you are suggesting - and we are trying to reduce the time spent in wind tunnels surely?

That's not how engineering works. In engineering you don't initially test a part by it's actual use. You estimate the loads and fatigue cycles it needs to go through. Than devise tests to measure if the part can sustain that load and those fatigue cycles and add acceptable margins in both based upon primarily how well the test simulates reality. For instance they don't put full size aircraft wings in wind tunnels and make them run the loads and cycles for the full expected lifetime of the aircraft.

So having gone through the introduction of the current aerodynamics in a safe and beneficiary manner, why do it all again for a problem that doesn't currently exist?

As already said, it is not primarily about fixing an urgent problem (although it does help against porpoising and would be required for battery powered motorsport in the future), it's about doing things in a better way. Better in the sense that it:

1 Makes the cars lighter. (due to lower power and fuel required). Something the drivers and a large part of the fans find important
2 Makes F1 more sustainable. Something all stakeholders find important (or at least, they claim)
3 More road relevant (lower drag coefficients). Something the manufacturers and the FIA consider important.
4 Is critical to allow top level battery power motorsport in the future. Something the FIA and manufacturers will find very important in the future.
5 Helps against the porpoising a little. Helps everybody.