2022 Aerodynamic Regulations Thread

[jjn9128]

And the front fences assembly! They are quite overlooked in the medias, but as far as I understand they'll play a big role by creating a big low pressure area around the center of the car and by sucking a big amount of air there.
Correct me if I'm wrong, but they might be more powerful than the bargeborads. We should call this assembly "the aspirator" as opposed to the diffuser and they can be considered as a new/fourth DF generator IMO.

Yes, without them that raised front section of floor would actually create some lift, being a bell-mouthed contraction it creates a bit of high pressure. Bargeboards have a specific purpose which has been optimized with the flat floor, these have a simpler purpose for the tunnel underbody.

I guess these fences will also create vortexes but how the latter will work? and wont these fences also create a big outwash?

How will the vortices work? Being in ground effect they stay pretty much in the same YZ location as they progress along the car, they help infer some low pressure on the suction surface; also might help keep flow attached in the diffuser, though it's not so aggressive a shape that separation may be an issue. IMO the vortex is less important than the low pressure from the shape of the vanes, teams might even try to reduce the vorticity.

I wouldn't say "big" outwash, though there is definitely outwash around the middle of the car, but I think less than current cars. I think they don't care about this so much because the rear end of the car is doing the job of "tidying" the wake.

[jjn9128]

It will be interesting to see how the teams approach ride height. Trying to run the floor as low as possible would seem to be sensible, or will a bit of rake still be beneficial?

I think some rake will still be beneficial, it's difficult to show in the 3-d pictures but the centre (inlet region/centre/diffuser) of the floor has a slight nose up inclination, so rake will the centre of the floor be an expanding volume. The rear wheel hub vanes then protect the diffuser from tyre squirt somewhat.

[jjn9128]

Seeing it like that, those venturi tunnels are tiny! Do you think the FIA should been more ambitious with specifying much larger venturi tunnels?

Though I guess it is also a misnomer that large venturi tunnels = less wake sensitive cars that can follow easily, so large tunnels may have been detrimental to racing?

The F1 tunnels seem to be a mere fraction of the size of the kind of thing seen on a time attack car or older Group C machines (though of course these vehicles are using much shallower rear wings):

That's the minimum size of the tunnel, they can actually be a bit wider. The only bit which is basically fixed for the width is the end of the diffuser endfence wall - basically enforcing vertical expansion of the diffuser not lateral. The narrow width of the diffuser exit is also to get the underbody wake onto the centreline then up into the air and above a following car. I think the FIA are petrified one team will come up with something which ruins the "close racing" initiative - I'm also on record here as saying I don't think "fixing" aero is the golden bullet for that.

The F1 tunnels are bigger than the mid-2000s Champ car floors they're ripping off.

[Xwang]

In your opinion with 2022 rules will the high aero concept still be used or not?

[Just_a_fan]

It will be interesting to see how the teams approach ride height. Trying to run the floor as low as possible would seem to be sensible, or will a bit of rake still be beneficial?

I think some rake will still be beneficial, it's difficult to show in the 3-d pictures but the centre (inlet region/centre/diffuser) of the floor has a slight nose up inclination, so rake will the centre of the floor be an expanding volume. The rear wheel hub vanes then protect the diffuser from tyre squirt somewhat.

That makes sense. My thought was only that if they can run the car low then they can limit the inflow from the side, and what inflow there is will give a powerful vortex along the outer edge of the floor tunnel which might be beneficial. Or might be absolutely unhelpful, of course.

[Just_a_fan]

The F1 tunnels seem to be a mere fraction of the size of the kind of thing seen on a time attack car or older Group C machines (though of course these vehicles are using much shallower rear wings):
https://i.pinimg.com/originals/8e/de/31 ... 369f55.jpg
https://upload.wikimedia.org/wikipedia/ ... 9_rear.jpg

I wonder how effective those big diffusers are. They look great but are they actually working fully? I remember reading that when the tunnels were becoming the norm in Grp C, a number of cars weren't nearly so fast as they thought they'd be. Over-expansion of the diffuser meant the downforce was lower than designed for and drag was higher as the flow through the diffuser was actually poor.

[jjn9128]

I wonder how effective those big diffusers are. They look great but are they actually working fully? I remember reading that when the tunnels were becoming the norm in Grp C, a number of cars weren't nearly so fast as they thought they'd be. Over-expansion of the diffuser meant the downforce was lower than designed for and drag was higher as the flow through the diffuser was actually poor.

IIRC some of the group C floors struggled because they were trying to copy the F1 "ground effect" concept - or air in at front and out at the back with skirts sealing. With no skirts to seal they basically choked the floor - too much mass flow. They worked better when they forced air in from the sides rather than the front.

[Just_a_fan]

I wonder how effective those big diffusers are. They look great but are they actually working fully? I remember reading that when the tunnels were becoming the norm in Grp C, a number of cars weren't nearly so fast as they thought they'd be. Over-expansion of the diffuser meant the downforce was lower than designed for and drag was higher as the flow through the diffuser was actually poor.

IIRC some of the group C floors struggled because they were trying to copy the F1 "ground effect" concept - or air in at front and out at the back with skirts sealing. With no skirts to seal they basically choked the floor - too much mass flow. They worked better when they forced air in from the sides rather than the front.

https://www.youtube.com/watch?v=PZxC-knQmkM#t=2m04.5s

Southgate got good performance by adding a lateral skirt along the side of the floor between the wheels. He cleverly made the bodywork narrower than the rules allowed which allowed him to place a "fence" sticking out from the side of the car parallel with the ground. Of course, the teams that used the full width allowed by the rules were unable to copy this clever bit of design.

Running a big wing low down as an extension of the rear deck helped the diffuser pull air through the floor.

[Noah Prandtl]

CzS is lift cofficient x frontal area, 3.75 x 1.47m2=5.5

Precisely!

Downforce (2019 car at 200mph)= 5.5(CzS) x 1.225kg/m3 x 89m/s (square) x 1/2 = 26924N = 2744kg!!

Downforce (2021 car at 180km/h) = 3.36 x 1.225kg/m3 x 50m/s (square) x 1.47m2 x 1/2 = 7563N = 770kg

You see why we don't quote absolute? You've mixed mph and kph in two calculations, not compared at the same velocity, then converted the force to a mass. So you have force (then mass) at a particular speed..

The problem is air density is not a constant, and neither in gravity, so you always have to qualify that it's only true at a specific speed and atmospheric condition - being sea level at 15°C. This is why we publish CzS or Cz, not sure why we chose to publish Cz over CzS in the article - I recall there was a discussion and rationale at the time but I just can't remember it.

I change 200mph to 320km/h in original post.
I use mass that people have better feeling how much downforce really is,at 320km/h almost 3 tons!

Air density depends on barometric pressure,temperature and humidity.
Downforce is not linear function,it is quadratic function, it increase with square of airspeed.

[Just_a_fan]

Air density depends on barometric pressure,temperature and humidity.
Downforce is not linear function,it is quadratic function, it increase with square of airspeed.

Wow, thanks for the insight...

[jjn9128]

Air density depends on barometric pressure,temperature and humidity.
Downforce is not linear function,it is quadratic function, it increase with square of airspeed.

Wow, thanks for the insight...

[Blackout]

Thank you jjn.

Is this nose tip with a keel legal? Edit: I dont think so
Anyways, I like the overall look of this render, although it's not very realistic. I prefer these sidepod intakes than those 'artistic' A1-GP-style sidepods of the official render and this engine cover over the outdated, fat and bland sidepod covers of the offcial render.

https://sketchfab.com/3d-models/f1-2021 ... 56fafe8658

[jjn9128]

Is this nose tip with a keel legal? Edit: I dont think so
Anyways, I like the overall look of this render, although it's not very realistic. I prefer these sidepod intakes than those 'artistic' A1-GP-style sidepods of the official render and this engine cover over the outdated, fat and bland sidepod covers of the offcial render.

https://sketchfab.com/3d-models/f1-2021 ... 56fafe8658
https://i.imgur.com/iE6dJQY.jpg

I don't know if it's possible in the rule volume, let alone the wording of the rules. That said if it's ahead of Xf -950mm and only inside the "RV-CH-NOSE" volume and not using the "RV-FW-PROFILES" volume it might well be legal. Not sure if it's desirable though.

The sidepod intakes are a bit up in the air right know AFAIK - could be the new side impact structure (not yet fully defined in the rules) forces the intake shape. Not sure the engine cover shape is legal, likewise the front wing.

[Blackout]

Thanks. So they only established the position of those structures, but not their shape?

[jjn9128]

Thanks. So they only established the position of those structures, but not their shape?

It seems they now have determined to keep the current side impact tubes, but their position is even more prescribed than before!

b. The structures must be mounted with the principal axes of their prismatic mounting sections perpendicular to the longitudinal and vertical centre plane of the car, and with the centres of area of their outermost longitudinal vertical cross sections positioned:
i. Longitudinally: between XC= -525 and XC= -475 for the upper structure and between XC= -525 and XC= -375 for the lower structure.
ii. Vertically: between Z=460 and Z=550 for the upper structure and between Z=100 and Z=240 for the lower structure.
iii. Laterally: Within 1mm of each other.

Where previously the rule said...

NOTE: for safety the two side impact structures will be replaced by a single, more comprehensive structure which is under definition. Consequently, all the ruling in Article 13.5 is likely to be modified.
The Side Impact Structure (SIS) will be classed as PDC, be defined in more detail in Appendix 6, and is also referred to in other parts of the Regulations, e.g. Article 3.7.1.