2022 Aerodynamic Regulations Thread

[wesley123]

Indeed, Pat Symonds has a clear view (from Racecar Engineering magazine):

F1 and the FIA don’t change rules. Anyone who’s worked in sportscars or worked in Formula 1 for a long while knows the phenomena. It’s fixable within the framework of the rules and the technology allowed on the cars now. As it always has been, the secret is to minimise the instability while keeping the performance.

As Symonds says, the phenomenon can be mitigated within the existing regulations (by some good engineering), he even gives a clue, "the secret is to minimise the instability while keeping the performance".

Bit late to the party here, but I find the quote rather intriguing. F1 is now changing the rules to fix the porpoising issues, which is a weird thing to do if fixing it is such a non-issue, as Symonds seems to imply here.

What bothers me more about it is that Symonds, who had years of windtunnel testing that wasn't limited by regulations, apparently didn't spot the phenomenon, or was completely oblivious to it. This same guy that didn't spot the porpoising in the years of testing is now pointing the finger at teams who literally were not allowed to simulate the occurrence(as they are not allowed to test at the required airspeeds, nor the frequency) and were all caught out as they ran their first laps in winter testing.

It would probably be less of an issue if teams could actually develop themselves out of it, but even this is an issue due to the limits placed on aero testing and funds.

They worked years on this ruleset, did huge amounts of windtunnel and CFD testing and yet somehow they were still completely unprepared to how teams would actually apply the ruleset, and they are now blaming the teams on flaws in their own ruleset.

[mzso]

Bit late to the party here, but I find the quote rather intriguing. F1 is now changing the rules to fix the porpoising issues, which is a weird thing to do if fixing it is such a non-issue, as Symonds seems to imply here.

What bothers me more about it is that Symonds, who had years of windtunnel testing that wasn't limited by regulations, apparently didn't spot the phenomenon, or was completely oblivious to it. This same guy that didn't spot the porpoising in the years of testing is now pointing the finger at teams who literally were not allowed to simulate the occurrence(as they are not allowed to test at the required airspeeds, nor the frequency) and were all caught out as they ran their first laps in winter testing.

It would probably be less of an issue if teams could actually develop themselves out of it, but even this is an issue due to the limits placed on aero testing and funds.

They worked years on this ruleset, did huge amounts of windtunnel and CFD testing and yet somehow they were still completely unprepared to how teams would actually apply the ruleset, and they are now blaming the teams on flaws in their own ruleset.

What the FIA is doing is setting safety limits, rather than changing the rules as such.
They were rather naive to expect the teams being reasonable.
I don't see why the rules should be blamed, it's the teams that came up with essentially defective designs, then refuesed to let go of even a little bit of performance to stop bouncing.

[Stu]

Indeed, Pat Symonds has a clear view (from Racecar Engineering magazine):

F1 and the FIA don’t change rules. Anyone who’s worked in sportscars or worked in Formula 1 for a long while knows the phenomena. It’s fixable within the framework of the rules and the technology allowed on the cars now. As it always has been, the secret is to minimise the instability while keeping the performance.

As Symonds says, the phenomenon can be mitigated within the existing regulations (by some good engineering), he even gives a clue, "the secret is to minimise the instability while keeping the performance".

Bit late to the party here, but I find the quote rather intriguing. F1 is now changing the rules to fix the porpoising issues, which is a weird thing to do if fixing it is such a non-issue, as Symonds seems to imply here.

What bothers me more about it is that Symonds, who had years of windtunnel testing that wasn't limited by regulations, apparently didn't spot the phenomenon, or was completely oblivious to it. This same guy that didn't spot the porpoising in the years of testing is now pointing the finger at teams who literally were not allowed to simulate the occurrence(as they are not allowed to test at the required airspeeds, nor the frequency) and were all caught out as they ran their first laps in winter testing.

It would probably be less of an issue if teams could actually develop themselves out of it, but even this is an issue due to the limits placed on aero testing and funds.

They worked years on this ruleset, did huge amounts of windtunnel and CFD testing and yet somehow they were still completely unprepared to how teams would actually apply the ruleset, and they are now blaming the teams on flaws in their own ruleset.

Wind tunnel models are fixed to the balance and are not set-up for high amplitude measurements to the best of my knowledge (such measurements would be filtered to reduce noise).

[godlameroso]

I feel the cars have too much diffuser area as is, and more can be gained by trading some volume for careful sculpting. Most teams designs seem to agree with my assessment.

The teams have tried to introduce some lateral outflow where the rules allow some leeway - the rules have tried to prevent lateral expansion of the diffuser for a good reason, but the top corner of the diffuser is a "free volume" - presumably to allow the teams to fine tune the shape of their diffusers. That most have chosen to use this volume to introduce lateral flow is not suprising.

Furthermore you don't have to have a thick rectangular partition using all the volume. The shaded blue region is an area where you may place bodywork, it doesn't have to occupy the volume entirely. You could put a fin there if you wanted, now whether it's a good idea or not is something that's left to debate.

As none of the teams have put anything in that volume, we can probably surmise that there is nothing to be gained by doing so. Perhaps as the cars develop in front of the diffuser, work in this area will prove fruitful, but it would appear at this stage in the rules, this volume is better left empty of bodywork.

I'm aware, despite being downvoted to oblivion by users who assured me no such thing was happening. Turns out I was right all along, eh I'll just add it to the pile.

[Just_a_fan]

Turns out I was right all along, eh I'll just add it to the pile.

In fairness, it's a small pile.

[Zynerji]

The safety reasons for banning the skirts didn't change since the eighties.

I wasn't talking sliding skirts, more like what the 2016 post-season mule cars ran to stimulate 2017 df levels...

How would it be different from the floor edge then? Which is essentially a skirt that may or may not touch the ground. How would it help at all?

It would work like the current skates on the floor edge, and guarantee that there is still an air channel to prevent choking even when bottomed out

[OO7]

A bit like the 2005 and 2006 etc Dallara GP2 cars, that had fixed skirts.

[Zynerji]

A bit like the 2005 and 2006 etc Dallara GP2 cars, that had fixed skirts.
https://www.speedsport-magazine.com/med ... -10952.jpg

More like:
https://images.app.goo.gl/2G7v5Hbs2F4gziSX7

[n_anirudh]

Indeed, Pat Symonds has a clear view (from Racecar Engineering magazine):


As Symonds says, the phenomenon can be mitigated within the existing regulations (by some good engineering), he even gives a clue, "the secret is to minimise the instability while keeping the performance".

Bit late to the party here, but I find the quote rather intriguing. F1 is now changing the rules to fix the porpoising issues, which is a weird thing to do if fixing it is such a non-issue, as Symonds seems to imply here.

What bothers me more about it is that Symonds, who had years of windtunnel testing that wasn't limited by regulations, apparently didn't spot the phenomenon, or was completely oblivious to it. This same guy that didn't spot the porpoising in the years of testing is now pointing the finger at teams who literally were not allowed to simulate the occurrence(as they are not allowed to test at the required airspeeds, nor the frequency) and were all caught out as they ran their first laps in winter testing.

It would probably be less of an issue if teams could actually develop themselves out of it, but even this is an issue due to the limits placed on aero testing and funds.

They worked years on this ruleset, did huge amounts of windtunnel and CFD testing and yet somehow they were still completely unprepared to how teams would actually apply the ruleset, and they are now blaming the teams on flaws in their own ruleset.

Wind tunnel models are fixed to the balance and are not set-up for high amplitude measurements to the best of my knowledge (such measurements would be filtered to reduce noise).

Permit me to add a bit more on this:

The FIA were not limited to use scale model testing - they could have gone anywhere with a full scale model testing and performed this test at realistic wind speeds. FIA testing was in line with what teams are allowed to do. - What is it now - 50% scale model at 180kmph max?while this phenomenon occurs at 270kmph+?

Secondly, teams ( and perhaps FIA by extension) mostly run RANS simulation and very very few of those use URANS/DDES type simulations and time scales to run these unsteady is large, and CFD would not have picked up on this.

Also, they would possibly use rakes/PIV and some local pressure tappings which could have indicated this transient/unsteady phenomenon - not just scales.

[wesley123]

What the FIA is doing is setting safety limits, rather than changing the rules as such.
They were rather naive to expect the teams being reasonable.
I don't see why the rules should be blamed, it's the teams that came up with essentially defective designs, then refuesed to let go of even a little bit of performance to stop bouncing.

It's probably a better wording, but I wouldn't really want to say the team are at fault here; They all adhere to the ruleset that is written by the FIA, and as it's a sport, of course they'll maximise the performance.

What is happening now is something that occurs because of the ruleset, which essentially mandates cars to run as low and as stiff as possible to maximize their performance. To say that teams should just not maximize the performance is like saying that the longer basketball players should jump a little less high(or whatever analogy that fits here).

And the naivety of FIA's expectation that teams would be reasonable is also intruiging, as a large part of these new regulations were also aimed at trying to stop teams from gaming the regulations.

Wind tunnel models are fixed to the balance and are not set-up for high amplitude measurements to the best of my knowledge (such measurements would be filtered to reduce noise).

Well, windtunnel models would be subject to a variety of issues; They for example wouldn't be able to scrape the belt very well.

Point being, Symonds and co weren't limited by windtunnel regulations unlike teams are and would have had the ability to actually spot the phenomenon in ways that the teams themselves cannot.

Afaik teams are allowed to change ride height 'on the fly', but the frequency on which they are allowed to do so is far, far less than the frequency of the porpoising itself.

So neither could the teams run high enough airspeeds to spot the phenomenon, nor could they actually 'force' the phenomenon to occur by applying this frequency in the windtunnel model. These are both things that Symonds and co were able to do so.

[godlameroso]

Indeed, Pat Symonds has a clear view (from Racecar Engineering magazine):


As Symonds says, the phenomenon can be mitigated within the existing regulations (by some good engineering), he even gives a clue, "the secret is to minimise the instability while keeping the performance".

Bit late to the party here, but I find the quote rather intriguing. F1 is now changing the rules to fix the porpoising issues, which is a weird thing to do if fixing it is such a non-issue, as Symonds seems to imply here.

What bothers me more about it is that Symonds, who had years of windtunnel testing that wasn't limited by regulations, apparently didn't spot the phenomenon, or was completely oblivious to it. This same guy that didn't spot the porpoising in the years of testing is now pointing the finger at teams who literally were not allowed to simulate the occurrence(as they are not allowed to test at the required airspeeds, nor the frequency) and were all caught out as they ran their first laps in winter testing.

It would probably be less of an issue if teams could actually develop themselves out of it, but even this is an issue due to the limits placed on aero testing and funds.

They worked years on this ruleset, did huge amounts of windtunnel and CFD testing and yet somehow they were still completely unprepared to how teams would actually apply the ruleset, and they are now blaming the teams on flaws in their own ruleset.

Wind tunnel models are fixed to the balance and are not set-up for high amplitude measurements to the best of my knowledge (such measurements would be filtered to reduce noise).

Smaller models means you have to increase air speed to get the same air behavior as a larger model. Air speed being limited to 50 m/s means the aero is being designed for ~40 m/s on a 100% car. To get a 60% model to give you accurate numbers for a 100% model at say 100 m/s air speed, you have to use 120-130 m/s airflow speed. This is not allowed, both by regulations and limited the energy required to get said airflow speed. In other words, the tunnel may not have enough 'umph' to get the airflow speed in the right window.

[godlameroso]

Turns out I was right all along, eh I'll just add it to the pile.

In fairness, it's a small pile.

I'll take it as a compliment.

[jjn9128]

Permit me to add a bit more on this:

The FIA were not limited to use scale model testing - they could have gone anywhere with a full scale model testing and performed this test at realistic wind speeds. FIA testing was in line with what teams are allowed to do. - What is it now - 50% scale model at 180kmph max?while this phenomenon occurs at 270kmph+?

Secondly, teams ( and perhaps FIA by extension) mostly run RANS simulation and very very few of those use URANS/DDES type simulations and time scales to run these unsteady is large, and CFD would not have picked up on this.

Also, they would possibly use rakes/PIV and some local pressure tappings which could have indicated this transient/unsteady phenomenon - not just scales.

To make a point I've made before, the aerodynamic research for 2021(2) rules was carried out by FOM, NOT the FIA. They then wrote the rules in conjunction with the FIA - but the FIA (Tombazis) had the final say. The FOM research groups are now within the FIA though.

Testing was carried out at 60% scale for cost reasons - volume increases by the cube so even for FOM and their greater budget vs the OWG study for 2009 rules, 100% model scale is out of the question. That's more done for final checks or BOP envelope studies in WEC with very few option parts. Even when Honda/Toyota/Sauber were running full scale it was for correlation, not for testing parts. FOM would have been able to run at higher Reynolds numbers than teams are permitted though as they used Sauber which IIRC is spec'd for 100% scale at 100m/s (teams are limited to 60% at 60m/s).

Most of the FOM CFD aero research was done using DES on AWS - there's even a presentation floating around the ether about how much DES they did vs an entrant - they collected loads of data, but the FOM aero department was only 5 people (that's aeros and surfacers) so they'd never find the performance an aero department in the 100s will. Things like the treatment of the floor edges might have taken them by surprise - there's huge potential there. Legal loopholes and all that.

It's their job to look at what teams are doing, predict the future and back off performance if they feel it's a safety issue. I'd rather they took some things away from the conscience of teams. Of course other areas I think are over-regulated.

[n_anirudh]

I think the specifics are slightly missin the point I was trying to make.

Fia/FOM could have taken the route of introducing this formula in f2 or gp2 series and then brought it up to F1. F1 could have kept the 2021 regs for a year more and lessons learnt could have been used for F1. Without the luxury of hindsight, and a strict budget cap and scale model research, there have been a few surprises this year.

I personally think the research group went on a design quest rather than investigating the full range of sensitivities for a given model. Not saying this is wrong, but these lead to constant tampering of the rules. F1 seems to have gotten used to working this way with TD’s and tweaks over the years.

[Vanja #66]

I'm aware, despite being downvoted to oblivion by users who assured me no such thing was happening. Turns out I was right all along, eh I'll just add it to the pile.

It's not an outwashing diffuser, it's an introduction of varying curvature in the diffuser corner for the vortex to attach to and lower the pressure a tiny bit more.

This is an outwashing diffuser, the curvature is much larger in outward lateral direction (than upward direction).



This is an upwashing diffuser, there is no curvature in lateral direction.



There is a clear difference. What's confusing you is a kink in the diffuser in the area where reflections got you to think there is a big outwashing curvature.



As for having a fin in diffuser, it prevents you from introducing the central ramp, which adds downforce. Unless your chassis is really low and/or other parts (suspension, etc) prevent you from having a ramp there, no racecar aerodynamicist would want a fin in that area.