Formula 1 Aerodynamics - article series and general discussion

[Just_a_fan]

perhaps it's more effective to make the floor even narrower, and focus on strengthening the vortex that forms inboard of the wheels. Use the whole length of the floor. Then the vortices that you induce travel inboard of the tire instead of smacking into it. Then you have a vortex acting as a buffer for the tire squirt even under yaw.

I've been having the same thought. Sure, by cutting back the floor you lose area that can produce downforce, but if it enables you to roll up a really strong vortex and throw it down the inboard side of the tyre, could it act like the blown diffuser edge of the late V8 era?

I guess the teams have looked at this and it doesn't work, or maybe they haven't looked at it because it's a bit weird to voluntarily take even more floor away.

I also guess that it would be too speed dependent and thus only really effective at high speed and not give any benefit in lower speed situations where, of course, most of the lap time is found.

[PhillipM]

The teams have already taken more floor away, that's why most of them have a square cut instead of a taper. This is nothing new, it's right there to see on a few cars.

[Just_a_fan]

The teams have already taken more floor away, that's why most of them have a square cut instead of a taper. This is nothing new, it's right there to see on a few cars.

Yes, We are (or rather I am) thinking about a much bigger removal in front of the rear tyre. Imagine the floor being cut back so that the outer edge of the floor is in line with the inner face of the rear tyre. The angle of the cut being such that it causes a strong vortex to be formed. This could be a significant cut out of floor, not just a small extra notch as most teams have done.

[PhillipM]

I think all you would do then is make the floor vortex get blow in too by the tyre squirt, and where it ended up would be very inconsistant because it'd depend on speed, tyre squash, slip and how much the tyre was flexing laterally at the time. If anything I think you'd make the rear more inconsistant and peaky.

[godlameroso]

I think all you would do then is make the floor vortex get blow in too by the tyre squirt, and where it ended up would be very inconsistant because it'd depend on speed, tyre squash, slip and how much the tyre was flexing laterally at the time. If anything I think you'd make the rear more inconsistant and peaky.

Currently the rear tire is being smacked on the inner corner with a vortex being shed by the floor. What does that vortex accomplish? The tire breaks it up almost immediately, and all it ends up doing is increasing the pressure on the rear tire tire, creating greater pressure difference at the rear, thus more tire squirt. The instability comes because the tire squirt migrates towards the center of the diffuser under yaw and roll. Which is what stalls it.

The lower rake cars are already inconsistent and peaky, for the above noted reason. Yes it's only a few mm, but that is enough to increase reduce the volume and thus velocity of the airflow being shed by the tire. To control the tire wake, to lessen its influence, to make the tire squirt weaker and less likely to stall the diffuser is the aim. To do that, you must lessen the pressure difference across the inboard length of the tire that runs parallel to the floor.

Sure, the tire turbulence getting trapped by the floor edge lowers the pressure of the tire squirt, in a straight line, but what about when the car turns, say a left turn. The tire wake on the left side is well controlled as the left side lifts up due to roll, and the vortex being shed by the floor gets pulled inboard of the tire. So far so good, the outside however is lower to the ground, the vortex being shed by the floor gets pulled on the outboard side of the tire if the yaw is too great. The tire squirt gets accelerated and no longer has the floor vortex keeping it in check, the lower car squishes the squirt into the diffuser and you get a partial stall on the outer edge of the diffuser.

This will become particularly apparent under trail braking and exiting very slow speed corners. At higher speeds it won't matter, but it will at low/low medium speeds.

[The_Truth]

See below a link to a great article by Enrique Scalabroni and Timoteo Briet. They explained what is the Rake and how it works on an F1 car. They run up to 70 hours of CFD simulation to create this article. The article is in Spanish though.

https://www.motorlat.com/notas/tecnica/ ... e-en-un-f1

[godlameroso]

What I mean is what effect does getting close to the wall have on the aero of the car itself. If ground effect works better the closer you get to the ground(to a point), out wash will work harder the closer you get to the wall(to a point)?

No it won't. They are different effects. The point of the outwash is to move the dirty air (front tyre wake) away from the car to the side. If you move a car close to a wall then that air has nowhere to go so you'll probably start to lose downforce as it means the dirty air will be forced to interact with the floor and other elements further down the car.

That's why drivers say they lose so much performance when driving next to other cars and one of the things making overtaking harder. The simplified front wings for 2019 was an effort to partially fix this.

How are they different, if you a confine a non compressible fluid it speeds up to a point. Aero works regardless of your orientation, in 3d space.

Furthermore cars lose downforce driving behind, not next to cars. 2019 rules just ended up costing teams money. They failed in their objective pretty spectacularly, and I would feel shame using that as an example of a well thought out rule change.

https://www.sciencedirect.com/science/a ... 5815036309

This seems to back up my reasoning.

[jjn9128]

See below a link to a great article by Enrique Scalabroni and Timoteo Briet. They explained what is the Rake and how it works on an F1 car. They run up to 70 hours of CFD simulation to create this article. The article is in Spanish though.

https://www.motorlat.com/notas/tecnica/ ... e-en-un-f1

3deg rake is quite extreme.

Also their formula e model from the start is quite interesting (inaccurate). Unfortunately I don’t have much Spanish to glean anything further than looking at the pictures.

[jjn9128]

No it won't. They are different effects. The point of the outwash is to move the dirty air (front tyre wake) away from the car to the side. If you move a car close to a wall then that air has nowhere to go so you'll probably start to lose downforce as it means the dirty air will be forced to interact with the floor and other elements further down the car.

That's why drivers say they lose so much performance when driving next to other cars and one of the things making overtaking harder. The simplified front wings for 2019 was an effort to partially fix this.

How are they different, if you a confine a non compressible fluid it speeds up to a point. Aero works regardless of your orientation, in 3d space.

Furthermore cars lose downforce driving behind, not next to cars. 2019 rules just ended up costing teams money. They failed in their objective pretty spectacularly, and I would feel shame using that as an example of a well thought out rule change.

https://www.sciencedirect.com/science/a ... 5815036309

This seems to back up my reasoning.

The 2019 change was a sticking plaster to try and back track some of the difficulties created by the 2017 rules. They helped a bit. But as anticipated all the out washing simply moved backwards to the barge boards and floor edges.

[godlameroso]

See below a link to a great article by Enrique Scalabroni and Timoteo Briet. They explained what is the Rake and how it works on an F1 car. They run up to 70 hours of CFD simulation to create this article. The article is in Spanish though.

https://www.motorlat.com/notas/tecnica/ ... e-en-un-f1

3deg rake is quite extreme.

Also their formula e model from the start is quite interesting (inaccurate). Unfortunately I don’t have much Spanish to glean anything further than looking at the pictures.

The article goes into depth in how aero forces affect the car while it moves under braking acceleration and cornering.

It is literally inverted flying. If the car turns right, then it rolls left, so the front wing gets closer to the ground on the left, so the left has more downforce, the problem comes when too much yaw stalls the diffuser, and the front still has plenty of load.

When you accelerate on a high rake car that has low heave compression wheel rate and damping, the car will squat on corner exit, and lift the front wing. When the car decelerates the diffuser height increases and the front wing gets closer to the ground. We see this in the onboard good vs great lap comparison from Formula 1. How Verstappen uses the brake to lower the wing on corner entry to get more weight transfer to the front.

The driver is in control of the aero platform, it works just like a plane, but upside down. The pitch roll and yaw of the F1 car steers it exactly like it would a plane, but inverted. Some drivers just have more advanced avionics in their brains.

[jjn9128]

Seems to ignore that steer angle drops the front ride height to keep the nose low to the ground.

[godlameroso]

Seems to ignore that steer angle drops the front ride height to keep the nose low to the ground.

That does it too, along with the natural motion of braking if your suspension is soft on front heave.

[Zynerji]

Seems to ignore that steer angle drops the front ride height to keep the nose low to the ground.

That does it too, along with the natural motion of braking if your suspension is soft on front heave.

Strong front 3rd spring, low slow bound/ rebound

[godlameroso]

Seems to ignore that steer angle drops the front ride height to keep the nose low to the ground.

That does it too, along with the natural motion of braking if your suspension is soft on front heave.

Strong front 3rd spring, low slow bound/ rebound

Exactly, stiff springs to control how much the suspension dives/pitches up, soft damper settings to speed up the weight transfer.

Dampers control timing of the spring rate. Stiff dampers resist motion soft dampers allow it. So in order to speed up weight transfer you need soft dampers. To slow it down you stiffen.

The damping at the rear can't be ignored either. As that controls how the rear end lifts under braking and roll. And how it squats under acceleration.

The rear suspension also affects the front. If the rear end squats under acceleration it raises the nose. Low front rebound on heave would help the rear squat under acceleration because the nose would pitch up faster.

[Tommy Cookers]

.... soft damper settings to speed up the weight transfer.
Dampers control timing of the spring rate. Stiff dampers resist motion soft dampers allow it. So in order to speed up weight transfer you need soft dampers. To slow it down you stiffen.

sorry but I think this is just .... wrong

the weight transfer is essentially independent of the routes taken by the forces between the CG and the wheels
weight transfer and body attitude aren't the same thing
using differential damper forces to adjust body attitude 'on the fly' isn't essentially a weight transfer matter

anyone ?