Front wing duct and stall theory

[allstaruk08]

ESPImperium wrote:
Could you stall one side of the wing and not the other in high speed corners???

if you was turning right which side would you stall, i was trying to figure it out and got muddled up lol. would you want to give more downforce to the inside wheel or the outside wheel?

[astracrazy]

could this not react in a similar way to the lotus device i.e connect to he suspension? in some long complicated way?

for example, if the suspension dips then it closes i.e car turns or slows.

I just looked at the hydraulic system of the lotus idea and thought what if its the same thing just it moves a valve in the nose

ESPImperium wrote:
Could you stall one side of the wing and not the other in high speed corners???

if you was turning right which side would you stall, i was trying to figure it out and got muddled up lol. would you want to give more downforce to the inside wheel or the outside wheel?

you would want the inside to have the most df?

[Ferraripilot]

super quick drawing but the idea is air goes in the front (3 arrows) and when you turn one of the slides cover the hole, so you turn left the left slide pulls across and a spring slides it back, or maybe angle the bottom of the slide so its like sliding up and when the car straightens up it slides back down a tiny slope

This was precisely what I had in mind only the slide valves would be located in the main plain of the wing and managed in a series of one hole for each pylon, but both sides connected so they were moving together.

[andylaurence]

Why would you want to stall one side in cornering? That would reduce grip on that side. Surely you want maximum grip in the corners and minimum drag on the straights?

If you want something that's g-sensitive, then you'll have to compromise on downforce in the initial braking phase as the flow attaches. I don't know how long this takes, but I know that braking is most effective at the start of the braking zone. It's easily achieved though - imagine a ball with a tube through it inside the duct. The ball is sprung so that the tube lines up with the duct in normal circumstances, allowing air to pass freely through the duct. A weight is hung from the bottom of the ball, which rotates the ball when subjected to lateral and/or longitudinal G. When it rotates, the tubes no longer line up and the duct is blocked. It's not affected by vertical forces unless augmented by forces in another plane, which means it doesn't activate over bumps on the straight. It's tuned by varying the size and shape of the tube and/or using a screw mount for the weight that moves the weight closer to or further from the ball. You can separate lateral and longitudinal G by changing spring rate in each plane. I can't be bothered to draw it on paper or in Sketchup, so you'll have to use your imagination to work out what I'm talking about!

[ESPImperium]

Flow in 2010 with the rear F-Duct was rumored to be between 0.5 of a cecond and a second for the less refined systems.

For the front wing this may be less now with the correct level of refinement.

Id say they could get it down to 0.2 to 0.5 of a second now.

But id recon that someone who is more qualified can answer this, maybe with CFD numbers would be ideal.

[Ferraripilot]

Flow in 2010 with the rear F-Duct was rumored to be between 0.5 of a cecond and a second for the less refined systems.

For the front wing this may be less now with the correct level of refinement.

Id say they could get it down to 0.2 to 0.5 of a second now.

But id recon that someone who is more qualified can answer this, maybe with CFD numbers would be ideal.

I actually believe if they can stall the front wing 30-40% then they are shedding a substantial amount of weight at-speed, which would yield time losses close to that of the rear f-duct. I forget how many 'points' of downforce the front wing usually is but even removing 25% during straight line acceleration would be massive.

[hardingfv32]

Where is your central air source? It can not be in the nose per the rules.

Brian

[Robbobnob]

i think you would also find that the valve would be classified as a moveable aerodynamic device, and hence would be illegal. F-duct was legal as it had no moving parts, and the driver acted as the moving actuator

[wesley123]

I'd agree with you Rob, this valve alters the aerodynamics of the car and therefore would be illegal.

Personally I would say it prevents stall by blowing the underside of the wing. This can be pretty useful with the movable splitter and the front wing getting close to the ground under braking. On this point airflow under the wing just isnt as good anymore, and this is on a critical point where you do not want to lose front downforce as this would prevent the car from turning in. This just makes the front less sensitive to ride height changes as well as increase downforce.

Due to the nature of the 2 plane wing I personally think this will have much more effect here than on a 3 plane wing(or more). On a 3 plane wing you'd already have the first plane split up in two, so air over the first plane would bleed under the second, preventing stall. In a 2 plane wing this slot doesnt exist so it is mroe sensitive to stall, this 'f-duct' will prevent it.

Just to let you guys think about it, front wing stall, doesnt that sound stupid anyway? You will send turbulent airflow under the floor, ruining the underbody efficiency and causing huge drag there.

Also to let this one stall it would always be in 'stall mode' unless operated by valves which in turn would be an movable aerodynamic device. I bet my 2c on a blown wing preventing stall.

[Raptor22]

have you considered that the stall may not be a flight stall like on the rear wing but a ground effect stall. i.e as the wing is lowered by aerodynamic forcesm when the suspension reaches a certain degree of squat a cable is sufficiently tensioned to lift the wing tips out of ground effect? It would sort of be a king of ride height control but at max speed the wing is lifted a few mm higher to remove some of the ground effect.

[Ferraripilot]

have you considered that the stall may not be a flight stall like on the rear wing but a ground effect stall. i.e as the wing is lowered by aerodynamic forcesm when the suspension reaches a certain degree of squat a cable is sufficiently tensioned to lift the wing tips out of ground effect? It would sort of be a king of ride height control but at max speed the wing is lifted a few mm higher to remove some of the ground effect.

yes I actually thought this was a better benefit to the wing than the drag reduction itself. I see this wing and reactive ride height systems as working together better than with just one or the other.

[Shaddock]

i think you would also find that the valve would be classified as a moveable aerodynamic device, and hence would be illegal. F-duct was legal as it had no moving parts, and the driver acted as the moving actuator

You don't need any moving parts to create an F Duct, just a chamber and some correctly angled pipes going in and out of it. Merc had a fully passive system on their rear wing a couple of seasons ago. Stalling the front wing as high speed sheds DF so you can run a lower front ride height or softer front end without scraping your plank on the floor.

[hardingfv32]

[Merc had a fully passive system on their rear wing a couple of seasons ago.

And we all know how well that system worked!

No, you must have a way to activate it.... and a central intake source for the air flow.

Brian

[Shaddock]

[Merc had a fully passive system on their rear wing a couple of seasons ago.

And we all know how well that system worked!

No, you must have a way to activate it.... and a central intake source for the air flow.

Brian

Moving parts are banned and so is driver interaction. Passive is the only direction left for teams. The Merc F Duct was no better or worse than the rest of car, and that was off the pace for most of the season.

The central air intake is suspected to be through the nose cone, and then down the pillars, into the wing.

[hardingfv32]

[The central air intake is suspected to be through the nose cone...

This is not allowed per the rules.

Brian