• Porpoising explained by an expert

    From Vasco Costa@24:150/2 to rec.autos.sport.f1 on Tue Apr 5 21:50:36 2022
    After some initially well laid out, but not factually correct
    explanations about porpoising on the media, here's a video with some
    insights by someone with more knowledge on the subject:

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

    --
    Vasco Costa

    AKA gluon. Enthusiastic about computers, motorsports, science,
    technology, travelling and TV series. Yes I'm a bit of a geek.

    Gemini: gemini://gluonspace.com/
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From texas gate@24:150/2 to rec.autos.sport.f1 on Tue Apr 5 21:22:58 2022
    On Tuesday, April 5, 2022 at 3:50:38 PM UTC-6, Vasco Costa wrote:

    Yes I'm a bit of a geek.

    you sound queer too
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From geoff@24:150/2 to rec.autos.sport.f1 on Wed Apr 6 22:22:50 2022
    On 6/04/2022 4:22 pm, texas gate wrote:
    On Tuesday, April 5, 2022 at 3:50:38 PM UTC-6, Vasco Costa wrote:

    Yes I'm a bit of a geek.

    you sound queer too

    And I always though 'porpoising' was what TexArseHole does on his
    boyfriend's dick.


    geoff
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From News@24:150/2 to rec.autos.sport.f1 on Wed Apr 6 09:52:01 2022
    On 4/5/2022 5:50 PM, Vasco Costa wrote:
    After some initially well laid out, but not factually correct
    explanations about porpoising on the media, here's a video with some
    insights by someone with more knowledge on the subject:

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


    Yes and no, but not really. 'Porpoising' is related to downforce, but
    it's not aero 'flutter' or twist, it's fore-aft, chord-wise, pitch
    instablity, with insufficient damping, not insufficient stiffness. The
    change in tire compliance is a factor, however.
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From Bigbird@24:150/2 to rec.autos.sport.f1 on Wed Apr 6 14:49:52 2022
    Vasco Costa wrote:

    After some initially well laid out, but not factually correct
    explanations about porpoising on the media, here's a video with some
    insights by someone with more knowledge on the subject:

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

    I thought the explanation on F1.com during testing was simple enough...
    and that didn't rely on an analogy to something else that most people
    not understanding porpoising already probably wouldn't understand any
    better.

    https://www.formula1.com/en/latest/article.analysis-what-is-porpoising-and-why-is-it-causing-the-f1-teams-a-headache-at.6O93LlvFMyY81L9LfSutcS.html

    --
    Bozo bin
    Felicity
    George R
    Irving S
    Texasgate
    Enjoy!
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From Vasco Costa@24:150/2 to rec.autos.sport.f1 on Wed Apr 6 17:41:42 2022
    On 06/04/2022, Bigbird <bigbird.nospam.usenet@gmail.com> wrote:
    I thought the explanation on F1.com during testing was simple enough...
    and that didn't rely on an analogy to something else that most people
    not understanding porpoising already probably wouldn't understand any
    better.

    https://www.formula1.com/en/latest/article.analysis-what-is-porpoising-and-why-is-it-causing-the-f1-teams-a-headache-at.6O93LlvFMyY81L9LfSutcS.html

    While in general the simplest explanation is the best explanation, that
    is not the case here. The movement itself is correctly described but the
    reason why it becomes so aggravated on the W13 isn't really mentioned.

    James Allison from Mercedes mentioned in one video that the media
    pundits, such as the one on that video you linked, got it wrong. If the
    reason was solely aero and simply caused by the downforce generated by
    the underfloor making the car bottom down and then back up, every team
    would have about the same levels of porpoising.

    There are two main aspects behind it, damping and aero, in that order.
    It's a compound problem, the bulk of the issue is probably related to
    how well each team is able to control damping. It all starts with the
    car being sucked to the ground, but this is a primary porpoising that
    every team experiences and can, in most cases, be controlled with ride
    height and changes to the design of the floor.

    The real issue arises (like explained in the video I linked) from the
    way the dampers react to this heave/pitch movement. The primary
    porpoising generates a moderate oscillation movement but then the
    dampers and general flexing characteristics of some cars, like the
    Mercedes exacerbate it, to the point the floor could be damaged. It's a
    bit like the natural oscillation frequency of their
    suspension/damper/chassis combination happens to be very close to the oscillation frequency induced by the underfloor aero. This leads to a
    resonance effect that magnifies the amplitude of the oscillation and
    therefore a much harder problem to solve compared to other teams, which
    don't happen to have a similar natural oscillation frequency.

    The rear suspension seems to be a bit more critical and perhaps a real
    fix requires a redesigned geometry. The way the chassis and power unit
    flex may also be a significant factor, which again highlights the
    difficulty Mercedes is facing.

    I'm sorry for the long reply and I reckon the goal of a neat description
    wasn't met, however this is a bit more complex and that's why engineers
    who know much more than us haven't figured a way to address it properly
    yet.

    --
    Vasco Costa

    AKA gluon. Enthusiastic about computers, motorsports, science,
    technology, travelling and TV series. Yes I'm a bit of a geek.

    Gemini: gemini://gluonspace.com/
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From Vasco Costa@24:150/2 to rec.autos.sport.f1 on Wed Apr 6 19:55:57 2022
    On 06/04/2022, News <News@Group.Name> wrote:
    Yes and no, but not really. 'Porpoising' is related to downforce, but
    it's not aero 'flutter' or twist, it's fore-aft, chord-wise, pitch instablity, with insufficient damping, not insufficient stiffness. The change in tire compliance is a factor, however.

    I think the flutter and twist analogy makes more sense when you realise
    that ground effect can be thought of as the whole car acting as a giant
    wing. Lower pressure on the underfloor and higher pressure above the
    car. The heaving and pitching movements are thus "flutter" and
    "twisting" motions of the whole car as a wing of sorts.

    Towards the end of the video he makes it clear that damping is the real
    secret to cure extreme porpoising.

    Like you said, tyres are probably a factor as well.

    --
    Vasco Costa

    AKA gluon. Enthusiastic about computers, motorsports, science,
    technology, travelling and TV series. Yes I'm a bit of a geek.

    Gemini: gemini://gluonspace.com/
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From Bigbird@24:150/2 to rec.autos.sport.f1 on Thu Apr 7 19:24:49 2022
    Vasco Costa wrote:

    On 06/04/2022, Bigbird <bigbird.nospam.usenet@gmail.com> wrote:
    I thought the explanation on F1.com during testing was simple
    enough... and that didn't rely on an analogy to something else
    that most people not understanding porpoising already probably
    wouldn't understand any better.


    https://www.formula1.com/en/latest/article.analysis-what-is-porpoising-and-why-is-it-causing-the-f1-teams-a-headache-at.6O93LlvFMyY81L9LfSutcS.html

    While in general the simplest explanation is the best explanation,
    that is not the case here. The movement itself is correctly described
    but the reason why it becomes so aggravated on the W13 isn't really mentioned.

    James Allison from Mercedes mentioned in one video that the media
    pundits, such as the one on that video you linked, got it wrong. If
    the reason was solely aero and simply caused by the downforce
    generated by the underfloor making the car bottom down and then back
    up, every team would have about the same levels of porpoising.

    There are two main aspects behind it, damping and aero, in that order.
    It's a compound problem, the bulk of the issue is probably related to
    how well each team is able to control damping. It all starts with the
    car being sucked to the ground, but this is a primary porpoising that
    every team experiences and can, in most cases, be controlled with ride
    height and changes to the design of the floor.

    The real issue arises (like explained in the video I linked) from the
    way the dampers react to this heave/pitch movement. The primary
    porpoising generates a moderate oscillation movement but then the
    dampers and general flexing characteristics of some cars, like the
    Mercedes exacerbate it, to the point the floor could be damaged. It's
    a bit like the natural oscillation frequency of their suspension/damper/chassis combination happens to be very close to the oscillation frequency induced by the underfloor aero. This leads to a resonance effect that magnifies the amplitude of the oscillation and therefore a much harder problem to solve compared to other teams,
    which don't happen to have a similar natural oscillation frequency.

    The rear suspension seems to be a bit more critical and perhaps a real
    fix requires a redesigned geometry. The way the chassis and power unit
    flex may also be a significant factor, which again highlights the
    difficulty Mercedes is facing.

    I'm sorry for the long reply and I reckon the goal of a neat
    description wasn't met, however this is a bit more complex and that's
    why engineers who know much more than us haven't figured a way to
    address it properly yet.

    Well that simply doesn't add up, does it?

    If you watched the video you would know this.

    --
    Bozo bin
    Felicity
    George R
    Irving S
    Texasgate
    Enjoy!
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)
  • From texas gate@24:150/2 to rec.autos.sport.f1 on Fri Apr 8 16:03:26 2022
    On Thursday, April 7, 2022 at 1:24:51 PM UTC-6, Bigbird wrote:

    Well that simply doesn't add up, does it?

    If you watched the video you would know this.

    Fuck off troll.
    Stick to dog walking.
    You are out of your league.
    --- SBBSecho 3.06-Win32
    * Origin: SportNet Gateway Site (24:150/2)