2017-2020 Aerodynamic Regulations Thread

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FPV GTHO
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Re: 2017-2020 Aerodynamic Technical Regulations

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Sevach wrote:
27 May 2018, 22:03
Slight ot, Indycar reduced downforce levels for this season... and we had one of the Indy 500's with less overtakes that i can remember and everyone complaining how it's impossible to follow.

The black art laughs in the face of theories again.
Most of the work changing the dow force/drag balance was done to the road course/short oval aero. Ive read they wanted to keep thr same downforce/drag balance for the superspeedway kits.

Sevach
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
27 May 2018, 23:07

Difficult to find values for the downforce of these cars but I've seen 5000lb (obviously horrendously rounded) quoted for Indycar on road courses and ~1/2 that for speedway. That's a Cz =2.87 based on a reference area of 1.6m*m (CzS =4.6) in road configuration, Cz =1.44 (CzS =2.3) on ovals - compared to F1 that's about 20% less downforce in road config and ~60% less on the ovals. They say the floor generates 66% on road tracks and 88% for ovals, so the underbody Cz is 1.9 and 1.3 respectively. F1 cars produce ~65% of their downforce from the floor which is an underbody Cz =2.3... I've never got the arguement that more floor downforce is the cure all solution.

Arguably with the Indy 500 though it's the reduction of the wake (size/intensity) from reduced downforce which has meant the slipstream effect is weaker - which means the draft pass is less possible. But you really need aero drag numbers to work that out.
What was being said was the opposite of that, cars were legit dangerous and nervous and even though you couldn't get close to overtake the draft was powerful enough that you get extra straight line speed from a car almost a full straight in front of you.
FPV GTHO wrote:
28 May 2018, 04:09

Most of the work changing the dow force/drag balance was done to the road course/short oval aero. Ive read they wanted to keep thr same downforce/drag balance for the superspeedway kits.
Well it didn't, wings got smaller(another theory taking a hit, ground downforce is better), cars cornering slower on qualifying runs and the race was crap.

If they actually wanted Superspeedway kits to be the same they could've just kept them while altering the road course car.

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jjn9128
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Re: 2017-2020 Aerodynamic Technical Regulations

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Sevach wrote:
28 May 2018, 09:16
What was being said was the opposite of that, cars were legit dangerous and nervous and even though you couldn't get close to overtake the draft was powerful enough that you get extra straight line speed from a car almost a full straight in front of you.
I didn't watch it - I'm sure it was more exciting than Monaco though?! I don't understand how the draft was that powerful yet there was no chance to overtake? They could draft up but then not make a move? If the cars were nervous that sounds like a balance issue - they shifted that forwards on the road course kit, did they do the same for speedways??

Are there normally more crashes and yellows? Who wrecked? Bourdais, Kanaan, Patrick, Castroneves??
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Sevach
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
28 May 2018, 10:13


I didn't watch it - I'm sure it was more exciting than Monaco though?! I don't understand how the draft was that powerful yet there was no chance to overtake? They could draft up but then not make a move? If the cars were nervous that sounds like a balance issue - they shifted that forwards on the road course kit, did they do the same for speedways??

Are there normally more crashes and yellows? Who wrecked? Bourdais, Kanaan, Patrick, Castroneves??
I got that you guys didn't watch it, clearly.
And sure it was better than Monaco, nothing could be worst.

All those experienced guys crashed in unforced errors, while they were seemingly just hanging about.

In the FP they were talking about how pwerful draft was, in FP with other guys on track cars were going easily faster than on qualifying runs, but once it got to following closely nobody could do it, everyone 2s apart, some action at re-starts.

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jjn9128
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Re: 2017-2020 Aerodynamic Technical Regulations

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Sevach wrote:
28 May 2018, 10:41
I got that you guys didn't watch it, clearly.
And sure it was better than Monaco, nothing could be worst.

All those experienced guys crashed in unforced errors, while they were seemingly just hanging about.

In the FP they were talking about how pwerful draft was, in FP with other guys on track cars were going easily faster than on qualifying runs, but once it got to following closely nobody could do it, everyone 2s apart, some action at re-starts.
It's not FTA in the Uk. That stuff wasn't mentioned in any of the articles I read. I can;t work out how the balance would go forwards to a oversteery condition... the floor tunnels should have a mid-wheelbase aero-balance... so the rear wing is loosing more than the front?
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Just_a_fan
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
28 May 2018, 10:51
so the rear wing is loosing more than the front?
Or the front is gaining somehow?
If you are more fortunate than others, build a larger table not a taller fence.

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Re: 2017-2020 Aerodynamic Technical Regulations

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Just_a_fan wrote:
28 May 2018, 12:44
Or the front is gaining somehow?
I can't comprehend that - I've seen it on a poorly optimized car (an early iteration of my own concept)... but surely Dallara and Indycar tested all that... I think they also do CFD with ARCIndy which is Adrian Reynard's company, so there's a hell of a lot of experience there.

My current supposition is - what is it's the effect of the front and rear experiencing the wake differently - so it's a result of the racing line chosen. As the wake is pushed towards the outside of the corner if the car behind crosses so it hits front then rear there's a sudden change of balance? All rear to all rear.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Sevach
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
28 May 2018, 10:51

It's not FTA in the Uk. That stuff wasn't mentioned in any of the articles I read. I can;t work out how the balance would go forwards to a oversteery condition... the floor tunnels should have a mid-wheelbase aero-balance... so the rear wing is loosing more than the front?
It needs a bigger investigation, all we now right now, less downforce from the wings, less downforce overall... and led to crappy racing.

Just_a_fan
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
28 May 2018, 13:13
Just_a_fan wrote:
28 May 2018, 12:44
Or the front is gaining somehow?
I can't comprehend that
I'm just chucking it in there as an option. There might be some flow off the car ahead that is beneficial to the front wing of the following car. That might also be detrimental to the rear wing of the following car too - after all we know that flow structures from the front affect the rear. Perhaps it's just that - the front wings are messed a little bit and the flow going rearwards gets increasingly suboptimal until the rear wing is just saying "nah, no thanks".
If you are more fortunate than others, build a larger table not a taller fence.

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jjn9128
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Re: 2017-2020 Aerodynamic Technical Regulations

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Just_a_fan wrote:
28 May 2018, 17:31
I'm just chucking it in there as an option. There might be some flow off the car ahead that is beneficial to the front wing of the following car. That might also be detrimental to the rear wing of the following car too - after all we know that flow structures from the front affect the rear. Perhaps it's just that - the front wings are messed a little bit and the flow going rearwards gets increasingly suboptimal until the rear wing is just saying "nah, no thanks".
I didn't mean that like "how can you suggest such a stupid thing" more I can't work out how it would work. My car gained at the front end because the wheel wakes travelled under the floor - in the wake the wheel wakes were reduced and the floor worked better. But that's just bad design.

I dunno any more we probably need to see some CFD.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Just_a_fan
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Re: 2017-2020 Aerodynamic Technical Regulations

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S'alright, I didn't think you meant anything by it. 8)
If you are more fortunate than others, build a larger table not a taller fence.

toraabe
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128
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Re: 2017-2020 Aerodynamic Technical Regulations

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The Indycar Superspeedway kit generates 88% of it's downforce from the floor... ground effect is good... but the aero is being blamed for an underwhelming Indy 500... how can this be... is ground effect not the magic bullet... error error does not compute... danger Will Robinson... ](*,)

In all seriousness thanks for that. Nico Rosberg is a clever guy... BUT his Dad's car produced less downforce than current cars. That's the main issue for following nose-to-tail not where the downforce is produced.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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djos
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Re: 2017-2020 Aerodynamic Technical Regulations

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jjn9128 wrote:
01 Jun 2018, 10:41
The Indycar Superspeedway kit generates 88% of it's downforce from the floor... ground effect is good... but the aero is being blamed for an underwhelming Indy 500... how can this be... is ground effect not the magic bullet... error error does not compute... danger Will Robinson... ](*,)

In all seriousness thanks for that. Nico Rosberg is a clever guy... BUT his Dad's car produced less downforce than current cars. That's the main issue for following nose-to-tail not where the downforce is produced.
Ovals are very different racing environments to street circuits so the comparison isn't valid.
"In downforce we trust"

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iotar__
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Re: 2017-2020 Aerodynamic Technical Regulations

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- WTF, slower cars and more DRS instead of getting rid of it and quickest cars evah :wtf: ?
- How very against fake purists' trends, clueless audience and marketing BS (quickest cars = most exciting sport).