2017-2020 Aerodynamic Regulations Thread

[Just_a_fan]

Shark skin has small teeth like structures in place of fish scales which are wonderful at reducing drag by "tripping" the flow of water.

But fabricating that crap in carbon fiber would be a real challenge.

Dermal denticles, yes, impressive bit of evolution that.

Whilst tricky in CF, a textured wrap could be used to good effect. After all, they developed a skinsuit system for swimmers on the same basis.

[bhall II]

There is no doubt that the teams are trying to control wheel wake in some manner or other.

Absolutely. My only objection - as ever - concerns the mythology disseminated by the "specialized press."

If you were to virtually "assemble" a hypothetical F1 car based upon popular analyses of each component, you'd probably end up with a low-flying airplane.

What started it here was the bizarre assertion that the appearance of an aggressive outwash design somehow heralds the imminent arrival of inwash wings.



It's weird.

[godlameroso]

That's still an out wash wing though, it just doesn't have the tunnel at the leading edge. The trailing edge was still flared out as if to guide airflow outwards.

[bhall II]

I didn't say it's not an outwash wing.

The question is what is it about that particular outwash design that could prompt someone to speculate that it signals a shift toward inwash designs?

Not that it necessarily makes much odds, but motorsport speculate that we may well see inwash:

http://www.motorsport.com/f1/news/tech- ... 17-855744/

With just this information you'd expect the outwash style wings to be retained, but it's the reintroduction of the larger bargeboards [4] behind them that is the game changer. As we've already alluded to, their role in pushing the front tyres wake away from the floor will change how designers approach the design of their front wing.



We've already seen and discussed how teams are potentially going to favour an inwash design philosophy, albeit with some outwash tendencies to displace and harness the airflow spilt by the outer section of the tyre, McLaren's development wing (above) points at this very direction.

(Hopefully, we've just dispelled the notion that air flow outside the wheel is anything but a relative non-issue in context.)

We didn't see inwash wings after Ferrari ran this concept throughout 2013...



Whenever I think I rag on journalists too much, I'm quickly reminded that the criticism is usually valid. If anything, McLaren's test article signals a switch to even more aggressive outwash designs.

Air flow always "prefers" to move from areas of high pressure to areas of low pressure. In other words, air flow tends to follow the path of least resistance.

On the high-pressure side of a F1 wing, that path is defined by sections of the wing where local angle of attack is lower than that of adjacent sections.

Where does that path lead on McLaren's test article?



Now, on the low-pressure side of the wing, the situation is quite logically inverted; the path of least resistance is defined by sections of the wing where local angle of attack is higher than that of adjacent sections.

Where does that path lead on McLaren's test article?

The purpose of the strakes on the low-pressure side of a front wing is to counter the tendency for air flow under the wing to move inboard while air flow over the wing moves outboard. If they're not moving in the same direction, that mean's they're slowing each other down. That's OK for the flap if the interaction is controlled, because it increases vorticity. But, on the main plane, it's nothing but bad news.

[godlameroso]

Does that mean that test wing was for an experiment in drag reduction?

[bhall II]

Quick primer: the reason for the introduction of revised endplates - or "vortex tunnels" - is that you want to direct air flow from the wing to areas where pressure is as low possible in order to delay separation for as long as possible. This maximizes efficiency.

Full-span wings, like the one equipped to F138, are perfectly acceptable when interacting with the outside wheel when cornering, because that wheel doesn't impede air flow from the wing. However, this is decidedly not the case for the interaction between the wing and the inside wheel.



Revised endplates address the problem by allowing air flow to pass both inside and outside the front wheels. The drawback is that it effectively reduces wingspan.

Next year's wings will have a larger wetted area thanks to a longer span a̶n̶d̶ ̶s̶w̶e̶e̶p̶ ̶a̶n̶g̶l̶e̶...



So, my guess is that McLaren was perhaps trying to see if new geometry can allow air flow from the wing to punch through turbulence around the contact patch in order to eliminate the need for revised endplates, i.e. "vortex tunnels."

Or it could just be a red herring. I read somewhere that McLaren's "viking horns" had no purpose. The team just wanted to force others to waste time investigating them.

[godlameroso]

I get you, so the wings would be wider than 1800mm if they didn't have the swept back shape. Regarding the end plates, will we see something similar next year?

[roon]

The sweep angle actually reduces the potential surface area in this instance. A parallelogram reduces in surface area as its angle increases. I'm not sure how much of the 2017 sweep angle negates the 100mm width increase, though. Pardon my terminology.

[roon]

My take is that the front wing shapes we see in photos have more to do with optimizing the basic function of a "wing-in-tire" complex. The wing in proximity to the tire, as in this case, makes it function like a wheel fairing as much as a wing. The wing AoA approaches 90* in front of the wheels. Seemingly they are trying to direct air above and around wheel regardless of steering angle. The wheel exists in the shadow of the wing. The 2009-and-up regs may have been written with the intent of reducing the drag penalty of unfaired wheels, without introducing wheel fairings, while still getting downforce.

Pre-2009 cars had the full front face of the tire exposed, for comparison. So while it looks inefficient to put a wing directly in front of an obstruction, it makes sense when considering the whole complex. Reducing the drag of an unaerodynamic wheelform while producing downforce using as few parts as possible.

[bhall II]

Air flow over a wheel can generate lift. I'm pretty sure that's why this front wing design was very short-lived, as those vortices likely kept air flow attached.



Though I'm sure it was unintended, the benefit of a layout that places the endplates in front of the wheels is that downforce, thus drag, is variable depending upon steering angle. Given no steering angle, the downstream blockages caused by the wheels reduce the efficiency of the wing. Since you don't really need downforce when driving straight, the drag reduction is beneficial.

I believe optimizing that dynamic is the challenge.

Regarding the end plates, will we see something similar next year?

I'm not sure. Even though swept wings will be new to the sport, designers have been working with swept elements and spanwise flow for a while...

[godlameroso]

Though I'm sure it was unintended, the benefit of a layout that places the endplates in front of the wheels is that downforce, thus drag, is variable depending upon steering angle. Given no steering angle, the downstream blockages caused by the wheels reduce the efficiency of the wing. Since you don't really need downforce when driving straight, the drag reduction is beneficial.

That's quite interesting, makes you think about if perhaps downforce increases as the car not only rolls but increases steering angle as the wheel becomes less of an obstruction for the endplates. So the inside wheel decreases downforce, the outside wheel increases downforce, and roll forces the outer wing closer to the ground to work harder in ground effect, while raising the inner wing. In essence generating aerodynamic yaw force, balancing the rear to work with this front aero concept would be difficult but rewarding.

[bhall II]

Missed this one...

The sweep angle actually reduces the potential surface area in this instance. A parallelogram reduces in surface area as its angle increases. I'm not sure how much of the 2017 sweep angle negates the 100mm width increase, though. Pardon my terminology.

I haven't looked through the regulations, because I don't speak Regulationese (and frankly I don't know how anyone can). I just assumed proportions would be unchanged next season. If not, omit that part of my post.

In essence generating aerodynamic yaw force, balancing the rear to work with this front aero concept would be difficult but rewarding.

Have we not been operating with the understanding that an effective manipulation of that dynamic is arguably the foundation upon which modern F1 aero is built? That's a genuine question, because it might explain some of the resistance I've encountered.

[trinidefender]

Speaking of the sweep angle of the 2017 wings being a big issue is imho a red herring. F1 aerodynamicists have been purposefully designing a sweep in their wings since 2009 with the trend being more and more sweep each season. This picture posted earlier demonstrates that quite well I think



Observe the flow lines. The sweep actually helps to and create more spanwise flow and which it turn creates more out wash and a stronger vortex in the tunnel beneath the wing.

There was an especially large increase in wing sweep when the wings were made narrower for the 2014 and onwards season. Aerodynamicists had to change designs to compensate for the loss of wingspan.

With the fatter front tyres I believe we will have some interesting designs being tried out next year.

[CBeck113]

There is a catch to the swept wing though: with an increasing ride height of the rear, like RB, then the end plates of the fromt wing will move further away from the ground, since their bottoms have to be parallel to the reference plane. I almost wonder if this was deliberate.....the two alternatives are to let the elements twist even more, or make the FRIC replacement system work even harder to sink the rear at higher speeds.

[Nickel]

There is a catch to the swept wing though: with an increasing ride height of the rear, like RB, then the end plates of the fromt wing will move further away from the ground, since their bottoms have to be parallel to the reference plane. I almost wonder if this was deliberate.....the two alternatives are to let the elements twist even more, or make the FRIC replacement system work even harder to sink the rear at higher speeds.

The end plates will move further from the ground vis-a-vis an unswept wing but raising rear ride height will still lower the whole wing as it's pivoting about the front axel. Raise the height behind the front axel and the height in front will drop, regardless of sweep.