2021 underbody Aero

[Shooty81]

As seen in the 2021 Aero CFD thread, there are these 2 inlets on each side of the car. First I thought the air would be guided from there under the car until the rear diffusor. But it rather seems the air is guided to the side, with the diffusor getting the air more from the inside of the car.

It can be clearly seen here

https://www.f1technical.net/news/22288

Can somebody explain in more detail why it is set up that way? Does it seal the floor to the sides?

[Maplesoup]

From what I understand air is pulled into the inlets by guiding turbulent air from the front wing and wheel wakes to the sides or over the body creating an area of low pressure that can pull cleaner air under the body to power the tunnels and diffuser.

[jjn9128]

The traditional "ground-effect" floor would have air going in at the front and out at the back with sealing skirts at the sides to stop air infilling to normalize the pressure. With the 2021 skirtless designs the air comes back into the diffuser - which can be seen by the massive pair of vortices in the diffuser exit. The fences at the front are pushing air outwards which creates low pressure (you can see on the back of the inner fence all the way across the centre of the floor), and should help stop the tyre wakes affecting the length of the floor - also they generate a vortex which infers a low pressure on the floor - much like bargeboards now.



Floors are not sealed without skirts. You can divert air to minimize the inflow, but it's not "sealing". It's a misconception started by the media and parroted in forums.

[Shooty81]

Ok, thank you. Good explanation. Is this geometry set in the rules? Or could the angle be varied or made with multiple elements?

[jjn9128]

Ok, thank you. Good explanation. Is this geometry set in the rules? Or could the angle be varied or made with multiple elements?

The geometry isn't set but it's quite tightly controlled. Teams can only have 3 fences on each side of the car, but they don't have to go all the way to the edge of the floor like we have, I can imagine some benefit of teams stacking 2 of them a bit like a multi-element wing. But it might give something away... it's something to test if we ever iterate on the car.

There were some variations in the joint FIA/FOM presentation

[godlameroso]

So in essence they shoved the bargeboards into the floor opening, as opposed to placing them in front of the floor as was previously done.

If you look at 2017 and onwards the floor leading edge has similar features as 2021, albeit not as extreme, and aided by the t tray extensions and bargeboards themselves.

It seems a bit of a letdown as changes are so subtle and restricted that we will have a harder time cataloging all the changes, as many won't be obvious.

Red Bull ran ~12 different front wings in 2019 but they were so restricted that most people only saw 5 or 6 changes total. A lot of the updates were detail changes, too subtle for most reporters to notice.

[Dazed1]

It seems like these designs would stop the running over curbs problem as you would lose aero and balance with every broken vane.

[godlameroso]

It seems like these designs would stop the running over curbs problem as you would lose aero and balance with every broken vane.

That's an interesting point, you would also have pieces of carbon fiber shooting out the rear of the car if they're not sturdy enough. Those pieces would pass right through the halo.

[jjn9128]

It seems like these designs would stop the running over curbs problem as you would lose aero and balance with every broken vane.

That's an interesting point, you would also have pieces of carbon fiber shooting out the rear of the car if they're not sturdy enough. Those pieces would pass right through the halo.

The same issue exists now. Broken bargeboards, the cheese grater floor edges, diffuser strakes, wing mirrors, front wing flaps/endplates.

[godlameroso]

It's a lot harder to break diffuser strakes as the rake of the car and diffuser height gives them a bit more clearance. Also a lot harder to break stuff by driving over curbs when the flimsy bits are on top of the car.

True the strakes are higher than the reference plane so the car will bottom out before hitting them, however certain curbs will have to be avoided now adding more challenge for the drivers.

[Jolle]

Drivers are well protected against carbon debris with the thick visors, carbon crash helmets and tear proof suits. If they loose bits over higher curbs, slashing tires is more of a concern.

[Just_a_fan]

Damage to the strakes will massively affect downforce so the drivers will be being careful.

[PhillipM]

You'd probably curb hop a lot less anyway as it's going to interfere with your aero a lot more.

[Just_a_fan]

The new "trendy tyres" might reduce kerb hopping anyway. Less sidewall means more risk of damage from the sidewall pinching over the more aggressive pillows.

[jjn9128]

I don't think this will enter the driver's thinking. They may be more wary of the big sausages, but those have never been ideal to ride over anyway.