2022 cars 'porpoising' at high speed

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter do not belong here.
User avatar
henry
324
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: 2022 cars 'porpoising' at high speed

Post

basti313 wrote:
Mon Mar 07, 2022 8:43 am
henry wrote:
Mon Mar 07, 2022 12:59 am

Eau Rouge is a special case. The compression makes for a very significant increase in downforce which will inevitably reduce ride height, probably by more than anywhere else on the calendar. If the porpoising is being triggered by low ride heights then it will be most likely to be triggered there. And since it’s in the middle of a high G corner complex it might cause some problems.
.
But at Spa you still have the compression pushing the car down, later it lifts a bit. So you have forces on the car. To my understanding purposing is the lack of force at some point, which can be seen as floor downforce oscillating: The car goes down and looses mayor part of the floor downforce, so it goes up. If you have additional compression or lift by the track, this will act like the DRS activation and damp the oscillating floor downforce.
I would also see the issue rather in situations where the wing is a bit bigger, not necessarily Spa or Monza. Might be an issue in Azer?

By the way: There is no more Eau Rouge. This issue will not happen there.
Good point. In my broad brush estimation the cars will have about 3G downforce as they approach Eau Rouge, 1 from the car mass and 2 from aero. On the exit of Eau Rouge where they hit the upslope they will gain 1G from the road shape. If this additional downforce triggers a loss of downforce from the floor it will depend how the combined downforce decay from this loss and the vertical road shape play out.

If they cancel out then the cars will progress to Radillon with no problems. If they don’t cancel and the car starts to porpoise then Radillon will be tricky, particularly since there is some loss of downforce over the crest.

Of course there may be no problem at all, in which case they’ll treat Eau Rouge/Radillon as a minor inconvenience in the straight. As they will many other corners on this wonderful circuit.

My understanding is that they have opened up the run off at Eau Rouge but not changed the track, am I wrong?
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

User avatar
mclaren111
272
Joined: Sun Apr 06, 2014 9:49 am
Location: Shithole - South Africa

Re: 2022 cars 'porpoising' at high speed

Post


piast9
piast9
20
Joined: Mon Mar 15, 2010 11:39 pm

Re: 2022 cars 'porpoising' at high speed

Post

I am still curious if under current regulations the underbody tunnels may be shaped in a way that they do not stall even if the car is so low that it is dragging the plank hard for miles. Is it possible?

User avatar
JonoNic
4
Joined: Thu Mar 05, 2015 2:54 pm

Re: 2022 cars 'porpoising' at high speed

Post

I'm trying to find an old video that I watched in the early 90s. Back then it was probably 15 years old already. The video investigated if a car with ground effects would lose downforce when driving over a bridge with a metal grid surface. Do any of you remember watching something like this?

Sent from my SM-G9910 using Tapatalk

Always find the gap then use it.

basti313
basti313
25
Joined: Sat Feb 22, 2014 1:49 pm

Re: 2022 cars 'porpoising' at high speed

Post

henry wrote:
Mon Mar 07, 2022 9:43 am
basti313 wrote:
Mon Mar 07, 2022 8:43 am
henry wrote:
Mon Mar 07, 2022 12:59 am

Eau Rouge is a special case. The compression makes for a very significant increase in downforce which will inevitably reduce ride height, probably by more than anywhere else on the calendar. If the porpoising is being triggered by low ride heights then it will be most likely to be triggered there. And since it’s in the middle of a high G corner complex it might cause some problems.
.
But at Spa you still have the compression pushing the car down, later it lifts a bit. So you have forces on the car. To my understanding purposing is the lack of force at some point, which can be seen as floor downforce oscillating: The car goes down and looses mayor part of the floor downforce, so it goes up. If you have additional compression or lift by the track, this will act like the DRS activation and damp the oscillating floor downforce.
I would also see the issue rather in situations where the wing is a bit bigger, not necessarily Spa or Monza. Might be an issue in Azer?

By the way: There is no more Eau Rouge. This issue will not happen there.
If they cancel out then the cars will progress to Radillon with no problems. If they don’t cancel and the car starts to porpoise then Radillon will be tricky, particularly since there is some loss of downforce over the crest.
.....
My understanding is that they have opened up the run off at Eau Rouge but not changed the track, am I wrong?
Yes, sorry. Track layout stays the same as I just learned. I thought they straightened it up following the comments from Hamilton and how the picture looked like. Just the run offs are bigger.


For the lift at Radillon: I think exactly this loss of downforce helps just like the open DRS. The back of the car lifts, the porpoising ends.

So we have three points of interest:
- Compression at Eau rouge - I think the compression keeps the car down.
- Uphill section - danger of porpoising. Question is if the speed is high enough?
- Lift at Radaillon - I see no danger, as the rear lifts as under DRS.


Do you know at which speed the porpoising started? In the videos it is a rather short area before the breaking point if I see it correctly.
Don`t russel the hamster!

Just_a_fan
Just_a_fan
591
Joined: Sun Jan 31, 2010 7:37 pm

Re: 2022 cars 'porpoising' at high speed

Post

The teams are working to stop the porpoising from happening - it's bad for performance after all. Judging by some of the solutions seen at the test, it might be as simple as stiffening the outer floor - Mercedes added a tie in this area to do just that, for example. Obviously any stiffening carried out will be inherent to the structure and not rely on big metal struts out in the airflow.

Let's see what the cars are like in the coming test and see whether they have solved the issue on the straights.
If you are more fortunate than others, build a larger table not a taller fence.

User avatar
JonoNic
4
Joined: Thu Mar 05, 2015 2:54 pm

Re: 2022 cars 'porpoising' at high speed

Post

JonoNic wrote:I'm trying to find an old video that I watched in the early 90s. Back then it was probably 15 years old already. The video investigated if a car with ground effects would lose downforce when driving over a bridge with a metal grid surface. Do any of you remember watching something like this?

Sent from my SM-G9910 using Tapatalk
By the way. The video concluded that the car would literally jump because of the compressed springs unloading and lose control as it transitioned from road surface to metal grid.

Sent from my SM-G9910 using Tapatalk

Always find the gap then use it.

User avatar
henry
324
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: 2022 cars 'porpoising' at high speed

Post

basti313 wrote:
Mon Mar 07, 2022 11:37 am
henry wrote:
Mon Mar 07, 2022 9:43 am
basti313 wrote:
Mon Mar 07, 2022 8:43 am

But at Spa you still have the compression pushing the car down, later it lifts a bit. So you have forces on the car. To my understanding purposing is the lack of force at some point, which can be seen as floor downforce oscillating: The car goes down and looses mayor part of the floor downforce, so it goes up. If you have additional compression or lift by the track, this will act like the DRS activation and damp the oscillating floor downforce.
I would also see the issue rather in situations where the wing is a bit bigger, not necessarily Spa or Monza. Might be an issue in Azer?

By the way: There is no more Eau Rouge. This issue will not happen there.
If they cancel out then the cars will progress to Radillon with no problems. If they don’t cancel and the car starts to porpoise then Radillon will be tricky, particularly since there is some loss of downforce over the crest.
.....
My understanding is that they have opened up the run off at Eau Rouge but not changed the track, am I wrong?
Yes, sorry. Track layout stays the same as I just learned. I thought they straightened it up following the comments from Hamilton and how the picture looked like. Just the run offs are bigger.


For the lift at Radillon: I think exactly this loss of downforce helps just like the open DRS. The back of the car lifts, the porpoising ends.

So we have three points of interest:
- Compression at Eau rouge - I think the compression keeps the car down.
- Uphill section - danger of porpoising. Question is if the speed is high enough?
- Lift at Radaillon - I see no danger, as the rear lifts as under DRS.


Do you know at which speed the porpoising started? In the videos it is a rather short area before the breaking point if I see it correctly.
From the recently released pictures the track looks the same but has a new surface.

I think the speed on entry to Eau Rouge is around 300kph, I don’t know what speeds they were doing in the videos.

I think the thing about DRS is it reduced overall downforce, keeping ride height higher, and so stopped porpoising starting as opposed to stopping it once it had started.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

User avatar
henry
324
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: 2022 cars 'porpoising' at high speed

Post

Just_a_fan wrote:
Mon Mar 07, 2022 11:49 am
The teams are working to stop the porpoising from happening - it's bad for performance after all. Judging by some of the solutions seen at the test, it might be as simple as stiffening the outer floor - Mercedes added a tie in this area to do just that, for example. Obviously any stiffening carried out will be inherent to the structure and not rely on big metal struts out in the airflow.

Let's see what the cars are like in the coming test and see whether they have solved the issue on the straights.
No doubt the teams will work hard at fixing this, but lap time comes first. A bit of porpoising on one straight at a circuit may be a price they are willing to pay.

I’m sure they’ll improve things at Bahrain but I don’t think it is one of the more difficult tracks in terms of track bumps or elevation changes. I raised Spa because I think it’s an outlier.

But as you say we will see at Bahrain what progress they’ve made, no doubt the observers will be on the lookout, more so than at Barcelona.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

Just_a_fan
Just_a_fan
591
Joined: Sun Jan 31, 2010 7:37 pm

Re: 2022 cars 'porpoising' at high speed

Post

henry wrote:
Mon Mar 07, 2022 12:59 pm
Just_a_fan wrote:
Mon Mar 07, 2022 11:49 am
The teams are working to stop the porpoising from happening - it's bad for performance after all. Judging by some of the solutions seen at the test, it might be as simple as stiffening the outer floor - Mercedes added a tie in this area to do just that, for example. Obviously any stiffening carried out will be inherent to the structure and not rely on big metal struts out in the airflow.

Let's see what the cars are like in the coming test and see whether they have solved the issue on the straights.
No doubt the teams will work hard at fixing this, but lap time comes first. A bit of porpoising on one straight at a circuit may be a price they are willing to pay.
Porpoising affects the driver as well as the car and a driver that isn't comfortable and confident in his car won't produce lap time. They need to sort it for that reason alone, even before the hypothetical worry about particular corners at particular tracks possibly being an issue.
If you are more fortunate than others, build a larger table not a taller fence.

User avatar
henry
324
Joined: Mon Feb 23, 2004 7:49 pm
Location: England

Re: 2022 cars 'porpoising' at high speed

Post

Just_a_fan wrote:
Mon Mar 07, 2022 2:11 pm
henry wrote:
Mon Mar 07, 2022 12:59 pm
Just_a_fan wrote:
Mon Mar 07, 2022 11:49 am
The teams are working to stop the porpoising from happening - it's bad for performance after all. Judging by some of the solutions seen at the test, it might be as simple as stiffening the outer floor - Mercedes added a tie in this area to do just that, for example. Obviously any stiffening carried out will be inherent to the structure and not rely on big metal struts out in the airflow.

Let's see what the cars are like in the coming test and see whether they have solved the issue on the straights.
No doubt the teams will work hard at fixing this, but lap time comes first. A bit of porpoising on one straight at a circuit may be a price they are willing to pay.
Porpoising affects the driver as well as the car and a driver that isn't comfortable and confident in his car won't produce lap time. They need to sort it for that reason alone, even before the hypothetical worry about particular corners at particular tracks possibly being an issue.
That’s a reasonable hypothesis.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

User avatar
vorticism
320
Joined: Tue Mar 01, 2022 7:20 pm

Re: 2022 cars 'porpoising' at high speed

Post

Sped up another porpoising video to real time:

https://i.imgur.com/faHEbmP.mp4
𓄀

algebraist
algebraist
1
Joined: Sun Sep 16, 2018 10:08 pm

Re: 2022 cars 'porpoising' at high speed

Post

henry wrote:
Mon Mar 07, 2022 2:31 pm
Just_a_fan wrote:
Mon Mar 07, 2022 2:11 pm
henry wrote:
Mon Mar 07, 2022 12:59 pm


No doubt the teams will work hard at fixing this, but lap time comes first. A bit of porpoising on one straight at a circuit may be a price they are willing to pay.
Porpoising affects the driver as well as the car and a driver that isn't comfortable and confident in his car won't produce lap time. They need to sort it for that reason alone, even before the hypothetical worry about particular corners at particular tracks possibly being an issue.
That’s a reasonable hypothesis.
It's not a hypothesis, this is something that was found before back in Colin Chapman's day with the Lotus 80. They dumped it for the 79 because it bounced so much the drivers were getting sick.

User avatar
vorticism
320
Joined: Tue Mar 01, 2022 7:20 pm

Re: 2022 cars 'porpoising' at high speed

Post

Happens to aircraft as well (feedback loop between a spring force and a lift force):



"Porpoising (runaway bounced landing) - repeated bouncing with bouncing amplitude increasing with each touchdown. This is most dangerous bounced landing type typically resulting in severe damage or destruction of airframe."

Q's: On the cars, is porpoising a pitching motion over the a particular center of pressure (f.e. tunnel waist, diffuser entry)? Is porpoising a more linear vertical motion? Is one axle affected more than the other?
Last edited by vorticism on Tue Mar 08, 2022 2:59 am, edited 2 times in total.
𓄀

User avatar
djos
112
Joined: Fri May 19, 2006 5:09 am
Location: Melbourne, Australia

Re: 2022 cars 'porpoising' at high speed

Post

vorticism wrote:
Mon Mar 07, 2022 11:50 pm
Happens to aircraft as well:

https://www.youtube.com/watch?v=x5ZzktAFJK4

"Porpoising (runaway bounced landing) - repeated bouncing with bouncing amplitude increasing with each touchdown. This is most dangerous bounced landing type typically resulting in severe damage or destruction of airframe."

Q's: Is porpoising a pitching motion over the a particular center of pressure (f.e. tunnel waist, diffuser entry)? Is porpoising a more linear vertical motion? Is one axle affected more than the other?
That pilot looks like he came in way too fast and that caused the Porpoising.
"In downforce we trust"