Active aero

[turbof1]

Also, remember that F1 designs are inherently compromised by regulations. So, nothing is ever perfect. If adverse interactions are present, then it might be because there's not a w

I know. It is why we have/had flex wings. You wouldn't see that in reg-free environment.

[bhall II]

Well, at the very least I think we've shown that active aero isn't a golden ticket to increased overtaking, if for no other reason than nothing about aero is ever that easy.

[turbof1]

Well, at the very least I think we've shown that active aero isn't a golden ticket to increased overtaking, if for no other reason than nothing about aero is ever that easy.

Not a golden ticket. Does it amount for atleast for some bread crums? Yeah probably. I guess you'll need to implement very radical ideas in order to fully compensate car wake.

I was wondering though: do we actually have ground effect on the plank? Would that be a viable target for skirts if we redesign the central part of the diffuser too?

[trinidefender]

Concerning the active aerodynamics that we have now, I actually believe that DRS has made this season far more of an engine based formula than it would have been without.

Let us look at McLaren as an example. How many overtakes have they made on the straights this season? I'll guess and say maybe 3. The rest have come from corners, the start line or through strategy.

Now how many times have they been overtaken on the straights. excluding from pitstops and the like, I would say at least 95% of the times they were overtaken on the straights. How many of those times that they were overtaken would not have happened if DRS had not been implemented, I'll bet quite a few.

This is really one for those who like to collect statistics over the season but might be interesting to look at to see how much of an effect simple DRS has in making a car look worse than it is just because the engine is underpowered.

[Andres125sx]

Regarding the overtaking problem and if active aero could help to improve it, I think there´s still a hope since active aero can be whatever you want.

For example:

I considered flaps, even telescopic bargeboards. But, if the regulatory "boxes" were enlarged to allow for such elements, then every team would just run bigger wings. If the size of those "boxes" was made variable based upon track position, which isn't even allowed under current DRS rules, then that would be just about as artificial as it gets.

As I said when you posted this, I think equalizing cars perfomances can´t be considered artificial. It´s not that you´re giving some advantage to someone (like DRS), but the opposite, you´re neutralizing a disadvantage.

So maybe an added flap they can only deploy like current DRS but in the corners instead of the straights?

Or maybe some sort of skirts for the front wing?

What about a movable nose wich turns the FW down some degrees so it increases a little bit AoA and at the same time reduce FW height so it improves GEs and DF?

[livinglikethathuh]

Deployable flaps are only practical for the rear wing, they will disrupt the flow structure going to the RW if used at the FW.
Variable AoA might stall the wing(s), especially when in dirty air and set close to the stalling point.

FW skirts could work, my only concern there is the flow going into the floor, but considering how neutered F1 floors are, it may not be much of an issue...

[bhall II]

It's possible front wing skirts would require the wing to have a reduced AoA, because they'd interfere with the end plate vortices that allow current wings to have a high AoA.

Though the following is taken from a diffuser study, the concept is generally the same.



Here's an example of the aforementioned vertical oscillation...


Big ups to Nickel for reminding me of this

As to the viability of an active front wing, it's possible if the performance envelope is constant, i.e. not periodic like DRS. It would just make aero mapping (very) complicated.

I tend to think a front wing equipped with what would almost be ailerons is sensible, because there's no reason for a car to carry downforce along straights. It's counterproductive for a formula that strives for greater efficiency.


via panggih15.wordpress.com

[Tommy Cookers]

......I tend to think a front wing equipped with what would almost be ailerons is sensible, because there's no reason for a car to carry peak downforce along straights. It's counterproductive for a formula that strives for greater efficiency.

yes, some planes have used this
(both wings) ailerons could be selected to 'upset' slightly above the neutral position, in cruise
so the outermost wing section has 'cancelled' camber/incidence effect equivalent to zero AoA/zero Cl (or close to that), and less drag

(though the benefit for the aircraft is reduced or zero lift far outboard, so reduced bending moment throughout the wing)
eg this was used on elderley UK RAF aircraft eg the VC10 and Victor to conserve their wing life

similarly, by extension, Tristar 'active ailerons' and modern equivalents alleviate outer wing gust loads (if not steady load)

[OO7]

.....similarly, by extension, Tristar 'active ailerons' and modern equivalents alleviate outer wing gust loads (if not steady load)

Yes, I believe the F/A-18's have this feature also.

[livinglikethathuh]

^In reverse, F/A-18 ailerons (actually called flaperons) move downward when flaps are lowered.

[OO7]

^In reverse, F/A-18 ailerons (actually called flaperons) move downward when flaps are lowered.

You are correct, this occurs in Power Approach (landing/take-off) mode. In Up Away mode (cruise and manoeuvring) the ailerons are scheduled to roughly 50% of the flap schedule. If you ever watch a Hornet perform a turn (more noticeable at high g), the flight control system will schedule the ailerons up while the flaps move downwards. This is part of the load alleviation strategy.

With regards to nomenclature, the primary means of roll control in the F/A-18 are the ailerons, with lift control being a secondary means and yaw control being tertiary, the reverse is true of the flaps (excluding yaw control). The F-16 however has true flaperons, as they function equally for roll and lift control

[Andres125sx]

You don´t need to go military to find active ailerons, even in RC world flaperons/spoilerons are extensively used.

In some categories, like pylon racing, they even use them for tight turns when the plane is banked 90 degrees (or almost) and the turn is done with elevator.

I guess in real aircrafts that´s not used because the limit is imposed by the pilot who can´t withstand more than 12-14Gs, so they don´t need more authority on the control surfaces, but on RC where there´s no pilot the limit is only the strenght of the plane so they can support more than 30-40Gs, and they use flaps/spoilers for tight turns mixed with elevator

[riff_raff]

One consideration with active aero devices is the amount of input power required to operate the device at the frequency and amplitude required. Using actuators to actively position a flap on the trailing edge of front wing airfoils at high frequency might not be the most efficient approach with active aero. It might be more efficient to use active aero devices (skirts, spoilers, guide vanes, etc) to improve the downforce performance of the underbody.

[trinidefender]

......I tend to think a front wing equipped with what would almost be ailerons is sensible, because there's no reason for a car to carry peak downforce along straights. It's counterproductive for a formula that strives for greater efficiency.

yes, some planes have used this
(both wings) ailerons could be selected to 'upset' slightly above the neutral position, in cruise
so the outermost wing section has 'cancelled' camber/incidence effect equivalent to zero AoA/zero Cl (or close to that), and less drag

(though the benefit for the aircraft is reduced or zero lift far outboard, so reduced bending moment throughout the wing)
eg this was used on elderley UK RAF aircraft eg the VC10 and Victor to conserve their wing life

similarly, by extension, Tristar 'active ailerons' and modern equivalents alleviate outer wing gust loads (if not steady load)

Having both ailerons set above 0 degrees to reduce outer wing loads and reduce induced drag is inefficient and something that a designer would add in only if they needed to as a result of problems found in testing when it is to late or costly to change the design. It is inefficient as it increases form drag, parasitic drag and you get some weird drag inducing flows from permanently offset ailerons while in cruise instead of being flush with the wing. If the problem is caught early enough then they will generally design some more washout into the outer sections of the wing. This will achieve many positive results over the method proposed by TC. It has the same benefit of reducing load on the outer sections of the wing and helps reduce induced drag (to a certain level), at low alpha levels it helps keep the outer part of the wing stable and reduces turbulence felt by the aircraft. Washout helps the outer part of the wing to stall at higher alpha levels than the inner portion, this maintains airflow over the ailerons and helps maintain control when flying the aircraft close to stall speeds (very important for safety and something every pilot will thank you for). Lastly with washout on a swept wing when the inner, more forward parts of the wing stall first the centre of pressure moves aft and drops the nose of the aircraft helping it to recover from a stall.

Before somebody states the obvious and says that it is rare that the ailerons would be flush with the wing that often because they will constantly have to adjust slightly let me say that at cruise speeds commercial airliners rarely use the ailerons for roll control. Above a certain speed the aircraft uses the airbrakes on the wing of the side of the plane that they want to roll to. The flight computers (whether they be analog on older aircraft or full FBW {fly by wire} on the modern Airbuses and such) decided how much roll input and deflection to put on the airbrakes of the wing to control roll. Using the airbrakes on the inner wing of an aircraft in a turn means that the rudder has to be used less as drag is already on the inside wing, this helps keep the turn coordinated.

TC for the Tri-star are you referring to the DLC (dynamic lift control)? It is a brilliant piece of kit and I've yet to meet a pilot yet who has flown that aircraft and didn't love it. It allowed very stable approaches and just made the pilots life a breeze even with autopilot off.

Note: alpha used here means angle of attack

P.s. Sorry for the OT, I'm just trying to give some context to some information presented in another post.

[trinidefender]

One consideration with active aero devices is the amount of input power required to operate the device at the frequency and amplitude required. Using actuators to actively position a flap on the trailing edge of front wing airfoils at high frequency might not be the most efficient approach with active aero. It might be more efficient to use active aero devices (skirts, spoilers, guide vanes, etc) to improve the downforce performance of the underbody.

When you say might not be the most efficient use are you saying that powered flaps wouldn't have the control frequency required to correct for bumps and such?