Lotus E20 VD

[N12ck]

That is pure speculation until we get a picture of the DRS system Open on the Lotus, it may be there, it may not be there, if it is that makes my theory correct, if it isnt, then the closed DRS part of my theory is still correct (although the open DRS part wouldnt be), but I think it is the best explanation thus far, as I havent seen any other explanations which clearly explain how the air is routed in such a system yet for drag reduction

[bhall]

I think you misinterpreted the question. I was not asking if they could plant a monkey seat on top of the pipe; I am asking if the curved edges of the pipe could produce downforce, like a monkeyseat.

No. A monkeyseat would completely reverse the effects of the duct slit, because a monkeyseat's job is to help keep flow attached to the bottom of the wing.

That certainly depends on the position of it. If they broaden the pylon at the round section, they would create downforce atht the expense of effectivly blocking the flow over it. And another way of decreasing the rear wing downforce was found.

There is reason they make the pylon as low-drag as possible, it would be straight from the airbox, if not for the aformentioned rule for bodywork in front of the rear wing.

And I misinterpreted the question, too.

It's important to note that the duct fairing's purpose is that of a diffuser to draw out air from the engine cover. I'm sure Lotus would love to actually connect it to the vent, but the rules don't allow it. But, as such, I don't see how it could be made to produce downforce and draw out air from the vent at the same time. Those roles are somewhat mutually exclusive here.

[bhall]

That is pure speculation until we get a picture of the DRS system Open on the Lotus, it may be there, it may not be there, if it is that makes my theory correct, if it isnt, then the closed DRS part of my theory is still correct (although the open DRS part wouldnt be), but I think it is the best explanation thus far, as I havent seen any other explanations which clearly explain how the air is routed in such a system yet for drag reduction

Then you're not paying attention. My explanation is an explanation, and it is based on photographic evidence.

Scoops + duct + duct slits = downforce reduction. Simple, easy, elegant.

Understandably, we all like our own brands the best; I get that. But I'd point out that your theory thus far relies on a drawing, a wink and a prayer. Just sayin'.

[N12ck]

That is pure speculation until we get a picture of the DRS system Open on the Lotus, it may be there, it may not be there, if it is that makes my theory correct, if it isnt, then the closed DRS part of my theory is still correct (although the open DRS part wouldnt be), but I think it is the best explanation thus far, as I havent seen any other explanations which clearly explain how the air is routed in such a system yet for drag reduction

Then you're not paying attention. My explanation is an explanation, and it is based on photographic evidence.

Scoops + duct + duct slits = downforce reduction. Simple, easy, elegant.

Understandably, we all like our own brands the best; I get that. But I'd point out that your theory thus far relies on a drawing, a wink and a prayer. Just sayin'.

Aerodynamically, you havent explained how it switches from one duct to another,

you have said that

Air is collected by the airbox scoops and directed to the engine cover vent/wing duct assembly. At a certain pressure threshold, the air flow through the duct is sufficient to cause separation. It's a simple little thing to gain a little bit of time.

this doesnt explain how the duct switching works, which is why I believe that the explanation for the passive system I have came up with is the most viable for explaining the switching

my theory relies on that image you posted and very kindly shown the slits clearly and my drawing to clear it up, it may not have the DRS coupling, but if you ignore the coupling the passive system works theoretically, but whether it has the fluidic switch aswell, we will see

[bhall]

My apologies. I thought I made that clear. Of course, I grew up an only child. So, I have an inner dialogue that I just assume everyone can hear.

Weird? Of course.

Air is drawn in from the airbox scoops. This is aided by the negative pressure caused by air being drawn out from the engine cover vent that exits within a diffuser to assist this extraction - also used for cooling, I might add. This flow is also vented from within the central duct that connects to the main plane of the wing via the slits at the connection. When that vented flow reaches a certain pressure - dictated by the airspeed of the car - the flow becomes sufficient to stall the central section of the wing. This action is enhanced when the DRS flap opens and reduces local pressure around the duct slits, which allows even more air to be vented.

It's simple. But, it's obviously not nearly as effective as I'm sure they'd like. That's just the way it is, though, because of the regulations and the need for a proper Mercedes-style Daffy Duct to be integrated into the design of a car from the outset.

[N12ck]

My apologies. I thought I made that clear. Of course, I grew up an only child. So, I have an inner dialogue that I just assume everyone can hear.

Weird? Of course.

Air is drawn in from the airbox scoops. This is aided by the negative pressure caused by air being drawn out from the engine cover vent that exits within a diffuser to assist this extraction - also used for cooling, I might add. This flow is also vented from within the central duct that connects to the main plane of the wing via the slits at the connection. When that vented flow reaches a certain pressure - dictated by the airspeed of the car - the flow becomes sufficient to stall the central section of the wing. This action is enhanced when the DRS flap opens and reduces local pressure around the duct slits, which allows even more air to be vented.

It's simple. But, it's obviously not nearly as effective as I'm sure they'd like. That's just the way it is, though, because of the regulations and the need for a proper Mercedes-style Daffy Duct to be integrated into the design of a car from the outset.

Hmm, interesting theory, I think next season, we will see several ducts on most the cars, stalling the front wing, rear wing, maybe even a downforce creating device like my original theory, they can go to town with this technology, DRS + Fduct = A cornucopia of opportunities

[superdread]

Hmm, interesting theory, I think next season, we will see several ducts on most the cars, stalling the front wing, rear wing, maybe even a downforce creating device like my original theory, they can go to town with this technology, DRS + Fduct = A cornucopia of opportunities

Let's see what the new rules say. Hoping for simpler, better structured rules is very well in vain I think.
Maybe they rule out that the DRS opens any holes or ban slits in the main wing.

A simply speed-activated DRS is something that we will not see in any form similar to current solutions. The turn exit speeds and therefore the DRS activation speeds differ so much throughout the race that such a system will hardly be effective.

[N12ck]

Hmm, interesting theory, I think next season, we will see several ducts on most the cars, stalling the front wing, rear wing, maybe even a downforce creating device like my original theory, they can go to town with this technology, DRS + Fduct = A cornucopia of opportunities

Let's see what the new rules say. Hoping for simpler, better structured rules is very well in vain I think.
Maybe they rule out that the DRS opens any holes or ban slits in the main wing.

A simply speed-activated DRS is something that we will not see in any form similar to current solutions. The turn exit speeds and therefore the DRS activation speeds differ so much throughout the race that such a system will hardly be effective.

I think its a dual system, both passive and active, and it could be tuned to the track, so it will activate at a faster speed than the fastest corner, e.g: to reduce the blockage effect at lower speeds they could make the outlet above the beam wing bigger, or if the speed on the fastest corner is slower than currently, they could make the outlet smaller to increase the blockage effect, as was the basis for my current theory, and see the diagram on the other page to understand it

[superdread]

I think its a dual system, both passive and active, and it could be tuned to the track, so it will activate at a faster speed than the fastest corner, e.g: to reduce the blockage effect at lower speeds they could make the outlet above the beam wing bigger, or if the speed on the fastest corner is slower than currently, they could make the outlet smaller to increase the blockage effect, as was the basis for my current theory, and see the diagram on the other page to understand it

Never mind, what Lotus has on its car. It remains to be seen, if a passive system, that could only be utilized in quali and the last parts of the race is worth its weight, time to set up and aerodynamic obstructions.

Could you adjust such a system under parc ferme? Because air temperature (=> air pressure) will certainly influence the total pressure that will open the fluidic switch sooner in colder conditions.

[N12ck]

I think its a dual system, both passive and active, and it could be tuned to the track, so it will activate at a faster speed than the fastest corner, e.g: to reduce the blockage effect at lower speeds they could make the outlet above the beam wing bigger, or if the speed on the fastest corner is slower than currently, they could make the outlet smaller to increase the blockage effect, as was the basis for my current theory, and see the diagram on the other page to understand it

Never mind, what Lotus has on its car. It remains to be seen, if a passive system, that could only be utilized in quali and the last parts of the race is worth its weight, time to set up and aerodynamic obstructions.

Could you adjust such a system under parc ferme? Because air temperature (=> air pressure) will certainly influence the total pressure that will open the fluidic switch sooner in colder conditions.

no you couldnt, as the outlet size above the beam wing would have to be changed, however, it is more about blockage effects I would think, as only so much air can pass out of a certain sized outlet at high speeds, leaving the rest to be directed up to the rear wing, thats how I believe the basic system works, whether or not it has an active duct or not, I dont know, but if it does, I would think it would work like my diagram

[superdread]

no you couldnt, as the outlet size above the beam wing would have to be changed, however, it is more about blockage effects I would think, as only so much air can pass out of a certain sized outlet at high speeds, leaving the rest to be directed up to the rear wing, thats how I believe the basic system works, whether or not it has an active duct or not, I dont know, but if it does, I would think it would work like my diagram

They will not use a simple blockage effect, as it's far too gradual. They want a stalling effect at a very precise speed. Else the system would not shed enough drag, when they are at top speed. Therefore I'm sure they would use a highly non-linear switch (I don't know how a good implementation of such a thing would look like, but I can think of several mechanisms that would achieve such an effect) and they were used before for the original F-Ducts.

[N12ck]

You can't use mechanisms as it will be classed as movable aero, unless drs is used which I think it is, there is no other way to make a passive system work well I don't think which is legal

[PlatinumZealot]

These slits.



And why would a duct this narrow cause so much flow separation?



Does the Coanda effect not apply to extremely narrow devices?

EDIT: And with regard to F1.com's odious explanation, the end plate fences have been on the car all year, and there's little reason to blow the area of the wing which sees the absolute least amount of pressure on the entire wing.

As I've said before, this is innovation when the rulebook is 77 pages long and loopholes get closed faster than Pastor Maldonado's temper.

Good work. that seems to be the answer!

And you see, that is original to this site right? You will soon see it on scarbs and F1 fanatic!

[PlatinumZealot]

My apologies. I thought I made that clear. Of course, I grew up an only child. So, I have an inner dialogue that I just assume everyone can hear.

Weird? Of course.

Air is drawn in from the airbox scoops. This is aided by the negative pressure caused by air being drawn out from the engine cover vent that exits within a diffuser to assist this extraction - also used for cooling, I might add. This flow is also vented from within the central duct that connects to the main plane of the wing via the slits at the connection. When that vented flow reaches a certain pressure - dictated by the airspeed of the car - the flow becomes sufficient to stall the central section of the wing. This action is enhanced when the DRS flap opens and reduces local pressure around the duct slits, which allows even more air to be vented.

It's simple. But, it's obviously not nearly as effective as I'm sure they'd like. That's just the way it is, though, because of the regulations and the need for a proper Mercedes-style Daffy Duct to be integrated into the design of a car from the outset.

Good method of reasoning, but some of it is i sort of disagree . Like the pressure behind the wing when DRS is open. Being that it is a drag reduction system, the pressure behind the wing is actually higher during DRS than no DRS.

[PlatinumZealot]

Doing some basic simulations on the slots.

I think it is a blown wing.

I don't know if it can stall or turn off like an F-duct, but indications seem to say it is adding down-force to the wing.

As you know the main plain is blown by the slots on the pylons and endplates, the pylon slots shoot jets of area span-wise across the wing. The effect is a high velocity peak running across the underside of the wing in a V-shape.

I have not put in the slots in the end-plates though, those would make a very interesting shape as those air streams would interfere with the ones coming from the pylon.

It is very clever of Lotus to put the slots in the pylon and end-plates in a reaction to the ban on slotted rear wings.