CFD - 2022 F1 Car

[Zynerji]

It's not impossible but it's possibly more effort/cost than is necessary for a purely aesthetic issue. Just wrapping the existing halo in a screen "because I don't like the halo" is also no justification.

Well engineers should like a challenge. Besides it would only have to be designed once, and only manufactured a few times. I don't expect them hitting damaging objects too often.

But it's not just aesthetic. It blocks a chunk of visibility. Particularly troublesome if the driver needs to look up a bit Spa (and Mugello and Portimao) come in mind.

Any device strong enough to, for example, punch through armco or deflect a flying car, is going to block vision at some point. An aero screen would either fail to perform or it would need to be so thick, or locally reinforced, that it too would block vision around the periphery.

I agree. And thickness of windscreen brings light-bending illusions as well.

[atanatizante]

We know that due to 2021 aero regs longitudinal holes/strakes/pilons etc. on the entire length of the floor are now banned but it`s allowed to have a Merc nose cape at the beginning of each car`s floor? Maybe positioned at the edges of the floor ... this could induce vortexs down the road towards diffuser in order to seal it?

[jjn9128]

We know that due to 2021 aero regs longitudinal holes/strakes/pilons etc. on the entire length of the floor are now banned but it`s allowed to have a Merc nose cape at the beginning of each car`s floor? Maybe positioned at the edges of the floor ... this could induce vortexs down the road towards diffuser in order to seal it?

Not sure what you mean, a raised leading edge with something like an endplate?? The floor rules are quite tight - the floor has to be on the reference or step planes with an edge radius of <100mm on the front edge, <50mm on the side of the step and <25mm on the transition between the planes.

Sealing the diffuser is technically not what the floor edge slots did, more managing the tyre squirt. Sealing can only be done with a skirt. That said inducing a vortex at the edge of the floor I can only see making the diffuser performance worse - you'd be rotating the flow under the car and raising the pressure under the car.

[Zynerji]

We know that due to 2021 aero regs longitudinal holes/strakes/pilons etc. on the entire length of the floor are now banned but it`s allowed to have a Merc nose cape at the beginning of each car`s floor? Maybe positioned at the edges of the floor ... this could induce vortexs down the road towards diffuser in order to seal it?

Not sure what you mean, a raised leading edge with something like an endplate?? The floor rules are quite tight - the floor has to be on the reference or step planes with an edge radius of <100mm on the front edge, <50mm on the side of the step and <25mm on the transition between the planes.

Sealing the diffuser is technically not what the floor edge slots did, more managing the tyre squirt. Sealing can only be done with a skirt. That said inducing a vortex at the edge of the floor I can only see making the diffuser performance worse - you'd be rotating the flow under the car and raising the pressure under the car.

Wow.

I think he meant like the tea tray, with the sides flipped up like a scoop.

I have a ton of respect for your aero knowledge, and you just blew my mind with that last part. I thought that other than skirts, a super strong vortex strung along the edge of the floor actually extended the low pressure zone outside the floor to keep high pressure air from sliding in. Then I thought the turn-out front wings/blown axles were adding a second "layer" further away from the seal vortex to reduce the high pressure even more.

Also, I was believing, for years, that all floors in F1 were vortex-stretching panels, with spinning air underneath them.

I am .

[Just_a_fan]

We know that due to 2021 aero regs longitudinal holes/strakes/pilons etc. on the entire length of the floor are now banned but it`s allowed to have a Merc nose cape at the beginning of each car`s floor? Maybe positioned at the edges of the floor ... this could induce vortexs down the road towards diffuser in order to seal it?

Not sure what you mean, a raised leading edge with something like an endplate?? The floor rules are quite tight - the floor has to be on the reference or step planes with an edge radius of <100mm on the front edge, <50mm on the side of the step and <25mm on the transition between the planes.

Sealing the diffuser is technically not what the floor edge slots did, more managing the tyre squirt. Sealing can only be done with a skirt. That said inducing a vortex at the edge of the floor I can only see making the diffuser performance worse - you'd be rotating the flow under the car and raising the pressure under the car.

Wow.

Sadly we're all misdirected by some of the stuff spouted by those who ought to be more careful. How often do we hear about "floor sealing" etc., from the commentators / pundits? Every time a bit is broken off a car, the phrase is used.

It would be great if F1 actually did a proper technical talk about the cars. It's not giving secrets away because the teams all know more about it anyway. But it would certainly help to kill some of the incorrect myths. And we'd all learn from it too, which would be great for the sport.

[Zynerji]

Not sure what you mean, a raised leading edge with something like an endplate?? The floor rules are quite tight - the floor has to be on the reference or step planes with an edge radius of <100mm on the front edge, <50mm on the side of the step and <25mm on the transition between the planes.

Sealing the diffuser is technically not what the floor edge slots did, more managing the tyre squirt. Sealing can only be done with a skirt. That said inducing a vortex at the edge of the floor I can only see making the diffuser performance worse - you'd be rotating the flow under the car and raising the pressure under the car.

Wow.

Sadly we're all misdirected by some of the stuff spouted by those who ought to be more careful. How often do we hear about "floor sealing" etc., from the commentators / pundits? Every time a bit is broken off a car, the phrase is used.

It would be great if F1 actually did a proper technical talk about the cars. It's not giving secrets away because the teams all know more about it anyway. But it would certainly help to kill some of the incorrect myths. And we'd all learn from it too, which would be great for the sport.

I specifically remember Kimis engineer in 2007 talking about the stair-step leading edge of the floor that produced multiple vortex, and that it was all about stretching them without breaking. He spoke that the edge was sealed by a contra-rotating vortex that sucked air out from underneath, but caused mass-airflow problems at the diffuser.. Maybe the 2009 rules changed that?

[jjn9128]

Wow.

I think he meant like the tea tray, with the sides flipped up like a scoop.

I have a ton of respect for your aero knowledge, and you just blew my mind with that last part. I thought that other than skirts, a super strong vortex strung along the edge of the floor actually extended the low pressure zone outside the floor to keep high pressure air from sliding in. Then I thought the turn-out front wings/blown axles were adding a second "layer" further away from the seal vortex to reduce the high pressure even more.

Also, I was believing, for years, that all floors in F1 were vortex-stretching panels, with spinning air underneath them.

I am .

Yeah but they specifically said at the floors edge.

There are a lot of vortices around an F1 car, most are trying to push air away from the floor. When you think about the direction of the flow field and then the orientation of the floor edge slots they start to make sense. They are pushing air down and out, aided by the strakes, as well as creating a bit of low pressure at the floors edge.

[dren]

Sealing the diffuser is technically not what the floor edge slots did, more managing the tyre squirt. Sealing can only be done with a skirt. That said inducing a vortex at the edge of the floor I can only see making the diffuser performance worse - you'd be rotating the flow under the car and raising the pressure under the car.

Agree on the tire squirt. Aren't there vorticies created at the start of the floor that rotate air to get all of the volume of air under the car energized rather than just the local layer to the floor?

[connorfolland]

G'day! It's been a while... hasn't it?

With the 2019 season now concluded, and jjn and I being in stage 4 withdrawals right now, we figured that we needed "something" to keep our mi... ooooooo!! Is that the 2021 regulations???

So, without further ado, I would like to present to you all our first, and legal (to the best of our knowledge), 2021 spec. F1 car!! And the first car that is wholly of F1T design!!

-sigh-... who would have thought that Aerosaruman and Aerogandalf would ever work together again, huh?

https://imgur.com/PYnaTVH.png
https://imgur.com/guOyb4N.png
https://imgur.com/IeQhAHn.png


So.......

What forum post from Vyssion would be complete, without some CFD: COLOUR FOR DIRECTORS!!

Very similar setup to the Perrinn model; straight ahead solve here, no crossflow or curved flow, steady-RANS w/ SST turbulence inc. wall functions, 31.5million elements, etc etc...


https://imgur.com/P6ED0ny.png
https://imgur.com/5R58Ahv.png
https://imgur.com/ThzSwAg.png


Here is a list of bullet points that, so far, we have twigged, and are gonna work on next. Now I am gonna shamelessly make excuses for any "iffy" performance or flow features you see, because... IT WAS OUR FIRST GO AT IT, OKAYYYY?? Overall, for a first go at it, the car performs very, very well; hats off to jjn.

• CzS = -4.95
• CxS = 1.80
• Front Wheel wake is pretty crazy now... we will work on this
• Going to reduce pitch setting of FW flaps
• Inboard floor fence vortex isnt under control (just spreads out)
• 2021 Force Breakdown = Floor (50%), FW (37%), RW (25%)
• Compared to Perrinn = Floor (55%), FW (30%), RW (40%)
• Higher than 100% is due to Lift generated on the chassis and wheels (6% lift on 2021 wheels, 9% lift on Perrinn)
• Balance of 2021 is ~49% which is quite far forward, so we will correct this (starting with FW flaps as mentioned above)
• Surprisingly large amount of low pressure below the car
• Front suspension is stalled
• Top of floor inlet is stalled
• Rear of Lower sidepod expansion has stalled
• RW flap stalled in curved EP sections (and slightly along TE) and RW as a whole is very draggy

-edit- replaced old gifs with larger ones - I made a mistake when I was creating them... oopsies
https://imgur.com/s0WIUwj.gif
https://imgur.com/rUTxoyq.gif
https://imgur.com/KYFQvuG.gif
https://imgur.com/2faOvGm.png
https://imgur.com/1wXjL5V.png
https://imgur.com/zTHRlNz.png
https://imgur.com/zueL8hT.png
https://imgur.com/bBaIjl3.png
https://imgur.com/9fPR6mf.png
https://imgur.com/kLcnClK.png

Hi Vyssion I'm new here and currently studying my 3rd year of aerospace engineering degree in the UK. I'm in the process of starting my final dissertation and wanting to do it around CFD analysis of the current F1 car against the new design and see how they compare and how the new designs allow for closer following cars and increased downforce at different distances.

I was hoping you had some pointers you could give to help me along the way or if its possible I could use any cad designs you had to do my own analysis of?

thank you in advance for any help given.

[jjn9128]

Hi Vyssion I'm new here and currently studying my 3rd year of aerospace engineering degree in the UK. I'm in the process of starting my final dissertation and wanting to do it around CFD analysis of the current F1 car against the new design and see how they compare and how the new designs allow for closer following cars and increased downforce at different distances.

I was hoping you had some pointers you could give to help me along the way or if its possible I could use any cad designs you had to do my own analysis of?

thank you in advance for any help given.

I would advise something more contained, like the effect of 2022 vs 2021 on the front wing and wheel/tyre wake region. Designing a whole car from the ground up, within the timeframe of a final year project, then having any confidence in the results is low.

I would use a geometry which is similar to these of a wing/nose and wheel (maybe add suspension but there's a whole other level of tweaking to make sure the susp arms aren't separating).




Even within that there's a lot of optimization to be done. Wing shape across the profiles and span, nose shape, if you add the cape in to the 2021 model and an S-duct...etc. You can do a lot more detail on a smaller part of the car!

[Tom888]

Why so low pressure at the "diffuser"/end of venturi tunnel(purple color)?

Here cant be so low pressure, this is place where pressure gradualy rise and meet car wake pressure(slighlty lower than freestream).

What will cause so low pressure at this area?

[Stu]

Why so low pressure at the "diffuser"/end of venturi tunnel(purple color)?

Here cant be so low pressure, this is place where pressure gradualy rise and meet car wake pressure(slighlty lower than freestream).

What will cause so low pressure at this area?

https://imgur.com/1wXjL5V.png

The rear wings create a low pressure area that helps to ‘pull’ the air through the diffuser (used inverted commas because this is not exactly how the physics work!), this increases the speed of the airflow through the underfloor (which in turn reduces the pressure within the tunnels).

[Tom888]

Why so low pressure at the "diffuser"/end of venturi tunnel(purple color)?

Here cant be so low pressure, this is place where pressure gradualy rise and meet car wake pressure(slighlty lower than freestream).

What will cause so low pressure at this area?

https://imgur.com/1wXjL5V.png

The rear wings create a low pressure area that helps to ‘pull’ the air through the diffuser (used inverted commas because this is not exactly how the physics work!), this increases the speed of the airflow through the underfloor (which in turn reduces the pressure within the tunnels).

Yes that makes sense but I doubt that wing lower side can affect pressure field so far away, perheps 40cm down under.

[Vanja #66]

Why so low pressure at the "diffuser"/end of venturi tunnel(purple color)?

Here cant be so low pressure, this is place where pressure gradualy rise and meet car wake pressure(slighlty lower than freestream).

What will cause so low pressure at this area?

https://imgur.com/1wXjL5V.png

This is not such a low pressure at all, Cp of -1 is not that low in F1 terms. Overall, jjn did an amazing job modelling the car and Vyssion did an amazing job with CFD. Still, as they said, there is a lot more performance on actual cars, much lower pressure in the middle of the floor, especially with car running without the rake.

As Stu said, the air right before the diffuser exit is sucked out by the rear and beam wings, which is the reason for lower pressure at the exit here. Also, venturi-tunnels are very different from flat-floor diffusers, there shouldn't be a big fence-vortex in them to generate the low pressure, so low pressure in that zone is expected.

[Tom888]

Why so low pressure at the "diffuser"/end of venturi tunnel(purple color)?

Here cant be so low pressure, this is place where pressure gradualy rise and meet car wake pressure(slighlty lower than freestream).

What will cause so low pressure at this area?

https://imgur.com/1wXjL5V.png

This is not such a low pressure at all, Cp of -1 is not that low in F1 terms. Overall, jjn did an amazing job modelling the car and Vyssion did an amazing job with CFD. Still, as they said, there is a lot more performance on actual cars, much lower pressure in the middle of the floor, especially with car running without the rake.

As Stu said, the air right before the diffuser exit is sucked out by the rear and beam wings, which is the reason for lower pressure at the exit here. Also, venturi-tunnels are very different from flat-floor diffusers, there shouldn't be a big fence-vortex in them to generate the low pressure, so low pressure in that zone is expected.

Where is throat located in 2022 cars, I expect here lowiest pressure?
Is there any real picture of undertray of these cars?

What is this two purple lines infront of back wheel, it seems like undertray has sharp turn up?
Or it has continuos radius like wing profile?