How Does Porpoising Work? - F1 Aero Explained

Porpoising is the hottest topic in the 2022 F1 development war. It has affected all the competitors in one form or another, but how exactly does it work? In this analysis we will look at aerodynamic fundamentals and CFD data to explain some theories on what the mechanism is behind F1 porpoising.
00:00 Introduction
01:42 Fundamentals of ground effect
03:29 Ground effect for different geometries
05:45 How a car behaves in ground effect
10:43 Hysteresis
12:35 CFD Introduction
14:22 CFD underbody interactions
17:24 Slicewise CFD analysis and ride compare
20:22 Where do you run the car?
21:27 Additional considerations
Aero courses: courses.jkfaero.com
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Facebook: / kyleengineers
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Instagram: / kyleengineers
KZbin: / kyleengi. .
Twitter: / kyleengineers

[@KYLEENGINEERS]

I really just want to stress that the graph lines from 4:20 to 5:40 are just really rough shapes off what I would guess on the fly by eye from 3D extruded wings from these airfoils, depending on the specifics the blue foil may have a higher peak downforce than the purple one, it massively depends on the geometry of everything. The point of that video section was just to get you thinking on the fact that the downforce curves can have different shapes and peak magnitudes. Hope everyone enjoys the video!

[@lq_12]

Hi Kyle, I want to tell you that I like your videos so much and also I want to ask if you have a video explaining the aerodynamics of the "bridge wing" of the 2008 regulations and why FIA introduced a mandatory section later on. I really don't remember who made that cool video, I watched a couple of months ago but I haven't found it again, don't know if you made it and then delete it. I don't even remember if it was in Spanish. Cool you explained porposing thank you so much

[@WorstPaperCut]

hello kyle...a friend of mine states that "aero need to be loose or else it will break under pressure". What are you thoughts on this.

[@thegreata3565]

You are great ❤ Thanks

[@andile5945]

I love your videos Kyle. I’m not sure if this would be considered rude, I want to ask of you to please label the axis for us younger engineers here. Thank you 😊

[@trumanhw]

Not to be critical (I hope you find it useful actually as a reminder) ... but pronouns (when we can't see what you're referencing - as I'm thinking you might ... have noticed during editing?) really should _never be used in your demonstrations._ Granted, sometimes the point is so obvious that you can use pronouns. but in that case, the sentence wasn't even necessary I think. Unlinked pronouns can only undermine an explanation's efficacy. I have a friend with _intermittent [eye cue] aptitude_ who'll say insightful things like, "I'm here" ... as if that's informative or as if I know where "here" is (which he didn't understand). I then asked, "when would ... or even _could it_ be false for you to say _I'm here_ ..?" I tried explaining that "here" is always the pronoun of where you define yourself to be. I think his Theory of Mind is the issue ... and, we don't choose our brains. We're just lucky or unlucky ... and if I understand something, it's not always because I deserve to, so I try to be patient ... and explain as best I can. But people who like racing (I'd assume) aren't people _known for their patience._ :-)

[@specialK319319]

I haven't finished watching this yet, but thank you for making this video. It's driving me nuts how many "arm-chair engineers" think they understand porposing "how hard can it be, the car just sucks down too much" and leave all these smug comments about how silly it is that they have this issue still because they solved it in X. Yet they have no idea whatsoever how complicated it is and why a "solution" from 30+ years ago won't work today. It seems to me that older F1 fans in particular (people like Peter Windsor) seem to have this gate keeping mentality about how engineering was "better" back in the day and how current F1 engineer's arrogance is one of the root causes of this issue . As someone that did FSAE and knows current engineers in F1, it just drives me up a wall as that thought process is absolute bullshit. I don't blame the F1 tech explanations F1 does as properly explaining it in 3 mins is impossible, but at the same time I wish they would emphasize more how much more complicated it is than the high level explanation they give. /end rant

[@Vamanos46]

Lost respect for Peter Windsor several years ago

[@GeraldL8]

I recently graduated with an ME degree. And these past few months have really emphasised why my lecturers always instructed us to review multiple sources of information. I've heard multiple explanations about porpoising that really left me asking "Is that really it?" I've been patiently waiting and hoping for Kyle to drop this video cause I knew he would go into more depth. But what's the issue with Peter Windsor? I watch his debriefs and I've always found them digestible. Simple even.

[@GeraldL8]

@@Vamanos46 Why?

[@n0ch91c3s]

@@GeraldL8 USF1 team...

[@jubuttib]

"the car just sucks down too much" Yes, the car is going wrong by doing what it's designed to do... Yeesh, I hadn't heard that one yet around my parts, the worst I'd heard was that the teams suffering the most from porpoising were trying too hard to optimize for absolute peak power near the ground (as opposed to not aiming as hard for peak and designing for a more stable "great" range).

[@samfisher2790]

Could you make a video about different possible solutions for this proplem? I think there are many different small things that the teams have come up to counter porpoising and maybe you could compare them to each other.

[@bart8596]

Nice try mr. Binotto

[@nFINITELooP]

I think it will be a waste of time. Teams have much more resources and probably used the solutions that Kyle will come up with.

[@wyattbrown4952]

@@nFINITELooP lol. the point is for people to be educated/entertained by his videos. F1 teams aren’t going to break down their solutions like these videos do, or take solutions from a KZbin channel. I would love to see a video about how certain solutions work

[@thethirdman225]

@@nFINITELooP Some of us would like to know.

[@FuRyZee]

@@thethirdman225 I think the problem is going to be a lack of detailed information. Its hard to draw possible solutions when he is working with a simplified model that has a lot of assumptions made in it. Combine that with the complexity of the transient effects, its just too difficult to offer any credible real world solutions.

[@ZenS56]

A breath of fresh air. As someone who also works in F1 and seeing many half-hearted, and frankly incorrect explanations, this is exactly what we needed. Hope you don't miss Unit 4 too much Kyle :)

[@muhafizpatel1503]

Ive been waiting for ages for your take on porpoising in F1. Love this video

[@TJohnsonLLC]

Finally, a rational explanation using cfd imaging. Kudos. Don't stop here.

[@ZZ-gv1pe]

With all respect to your day to day work: we need more videos! I found myself looking for new videos on your channel too often 😄

[@CarsSimplified]

Some of the best automotive engineering content not just on KZbin, but the whole Internet!

[@TheConceptarchitect]

Your CFD render is one of the most beautiful things I've seen!

[@racingjets1]

The video i didn't know I needed

[@zlm001]

Thank you. Best explanation I've seen by far. No one else has I know of explains it like this.

[@TheFarCobra]

Carroll Smith talked about proposing in his books. Back then it was generally the download reducing ground clearance at the front wing to the point where it would choke off the lower surface and, effectively, stall the wing …. Reducing the download and causing the car to pop up. As I recall there was some natural frequencies within the car would amplify the situation.

[@eck0hcobra15]

I wonder if it's a bit annoying to put so much effort into making this and getting lots of comments that ask for another video about something else. I really appreciate how you approached this topic. Helps me have a more open mind about how teams work on finding solutions. I am incredibly grateful that you have made your insights avaliable

[@sponge3968]

This is truly fantastic. Only person I've found who goes into this level of detail. Thanks!

[@thethirdman225]

Great explanation Kyle. I’ve been looking forward to this for months. I was one who -probably- got it wrong because I saw it as a pitch problem that simply (nothing simple about it) meant less downforce as the rear springs compressed, due to a less optimum AOA. I definitely get the hysteresis component and that explains the cyclical nature of it perfectly. Thanks so much for putting this together. It’s so much better and more complete than anything else out there.

[@leo1fun]

Awesome insights. Specially the bumpstop and the suspension acting as the bouncing agent. That opens up a lot of possibilities for each teams' particular porpoising scenarios.

[@jensenyang337]

Awesome analysis. Really appreciate this video highlighting how complex of a problem this really is

[@peterdiamond9583]

I really like this video. So cool to learn that there are different causes, before I thought it was just simple choking of the underfloor

[@23Pixels]

Thanks for this video! Whilst I don't understand it entirely still, much more informed as to how hard of a problem it is to solve. Keep up the good work!

[@jonas73862]

Just wanted to thank you for the awesome and informative videos. Keep going!

[@gjackson123456]

Great stuff Kyle, thank you. Certainly the most comprehensive and detailed (therefore best) description of the problem.

[@zMaSpEdiTz]

Hell of a video! As an eng student I can say that your videos are basically a direct link between an academic and a working perspective. Thanks a lot

[@Ginbaubabe]

Been eagerly waiting for this 1. Again excellent analysis thanks Kyle!

[@melroks3]

Was waiting for a video on porpoising from you. Really nice explanation. thanks🙌🏼

[@andrewharpin6749]

Thank you, nice to hear someone not over simplify the problem and provide some higher level understanding to the issue. I don't understand all the issues presented, but I am not an aerodynamicist.

[@whyyoulidl]

Thanks. Most in-depth and knowledgeable explanation.

[@EnterScreenameHere]

Would love to see more videos from you. I enjoy the educated take from an engineer that has real experience in f1.

[@andybakr]

Superb explanation, bringing back so many memories 👌

[@konholio2]

Amazing video and overall channel content. Fluid dynamics was one of my favorite subjects in university.

[@zolimajster8313]

Ok, it's complicated then :D I was waiting for this piece for so so long. Good to hear from You again.

[@TommyMacUK]

Amazing explanation with great CFD visuals!

[@xdoctorblindx]

Brilliant explanaition - thank you for this!

[@lascellesreid-barlow8250]

Glad to see your still making vids Kyle, I hope you are well

[@Osprey6m]

Brilliant. Keep them coming, this is how we will learn and understand. It would be interesting for you to follow up with a video as to how you decision analyse the trade offs to come up with a self reinforcing concept.

[@juliusfucik4011]

I love how you draw the curves with measurement noise ❤

[@poomtnp1253]

Kyle thanks for the video. Really love how you explained it. ❤️

[@jozsefizsak]

Thank you. I consider yours to be the premium F1 tech channel and this video certainly sets a high bar.

[@proesterchen]

Thank you for the detailed explanation! 👍

[@phillipmartin2213]

Very informative. Thank you so much for sharing! I learned a lot.

[@raykreiger4123]

Gonna be excellency content!

[@HansBrodiAutomotive]

Fantastic video! Thank you.

[@GUITI]

this is amazing. I kinda have an Idea of how aero works around f1 cars (in terms of use of various vortex & roughly what they want to achieve) but this video really helps understand especially with the 2D sections comparing between ride heights, what the teams have going on. Great video! If you could maybe make a video about the different car upgrades & their intention, like you did in preseason testing, it would be amazing.

[@fernandoalo8995]

Amazing video, really well explained!

[@indopleaser]

very cool video yet again!

[@max-01]

Wow, an excellent video about porpoising!

[@minime453]

Thank's for the vid!

[@GerrardTorres7665]

Another fantastic video. Great content.

[@rbattistin]

Great video! Thanks for the explanation!

[@VTiDOHC]

Great video Kyle, chatting on the podcast I can now see why the common oversimplified explanation does no justice to the phenomenon at hand. Thanks for this!

[@valentinjakob2109]

That's an absolutely mega video!!👍👍👍

[@paultijink4235]

That was a great explanation! Thanks!

[@rodrilinares6734]

Love it, thanks man!!

[@ScottMoyse]

That was freaking awesome. Thanks!

[@jeffcole75]

You're back making F1 content, rejoice!

[@MostCedric]

Thanks. Top-tier content.

[@patbounds3739]

I was wondering if you or someone else could explain in a little more detail what is meant when you say that a vortex becomes"lossy". When I hear this, it just makes me think that it can mean multiple different things. A little elaboration would be greatly appreciated.

[@Yamagatabr]

It is harder to gather energy from turbulent flow because the fluid does not behave strictly as intended. And it also may disperse the fluid to a more static movement. i'm not an expert, tho

[@Unamatrix01]

Fantastic video, Kyle explaining the various causes of porpoising. Would it be possible for you to make an accompanying video showing possible aerodynamic and suspension solutions, obviously not including active suspension systems as a way of neutralizing the porpoising effect?

[@user-fq3rr4cw5t]

thanks for making this video!

[@RB26N]

very very good video, thank you very much.

[@samghost13]

Thank you Sir! Finally! There was so much talk and so much BS! Always good to have a real Aero Genius to get the real Information to us! BIG THX!

[@OBA_911]

Very good job. Thanks

[@karlkennedy4083]

bring back active suspension! the whole point of the most recent regulations is to make the cars more similar to road cars. we are starting to see extremely complex active suspension in road cars. it would be great to see it in f1 and fix all these issues.

[@david1rosenthal]

The hysteresis explanation is the one that makes the most sense to me. The suspension dampers will be working pretty hard to dissipate energy from porpoising so something has to be pumping a decent amount of energy into the system to keep the oscillation going. The shape of the downforce vs. ride height curve might be wacky (and might even admit multiple "stable" ride heights at a given speed!) but I think it's a red herring as it doesn't answer the question as to what is putting energy into the system (if downforce was purely a function of ride height then going up and down any such curve would be energy neutral.)

[@roylinbobs4621]

Tq for the knowledge, its really mind blowing, love it, the explanation is really good, i do understand tq again

[@MrPhilePhil]

Well done sir 👍🏾

[@stupidmonkeykev]

Cheers for this, may need to watch it again tomorrow and try and digest more. But that is just the sort of above-my-head aero comments I want to try and understand a n'th better.

[@shadowgaming6660]

You can recreate porpoising in your own home. Get two spoons, face the two spoons away from each other pointing downwards whilst keeping them close to each other (almost touching but not quite). Then run them under a tap, and they'll be pulled together until they touch, then disconnect repetitively.

[@mosca3289]

Love it. Kitchen sink fluid dynamics.

[@rolandotillit2867]

If the wing touches the ground the stagnation region grows like crazy, I paid attention when you were talking about adverse pressure gradients. More stagnation leads to more APG, more APG means more turbulence and recirculation ie lots of drag and losses. Turbulent airflow is on average about 1/3rd as efficient as laminar flow depending on surface roughness.

[@phantomracer7216]

I know if you ever ran an unsteady case, those vortices would be dancing all in those channels, like a frat party. LOL Nice video! Thank you!

[@rh1300s]

Great content thanks

[@rohansonkusare7025]

Brilliant video Kyle. I'm glad someone is using proper engineering tools to understand engineering problems. And even though you don't have the actual data about the dimensions and operating condition for these cars, an educated estimated still works in explaining the problem. My only feedback will be to show the legends and magnitudes for all the plots because otherwise we are just looking at colors and distribution patterns. If I want to conclude that the static pressure advantage of the low-ride configuration outweighs the energy losses, I would like to see the magnitudes of the static, dynamic and total pressures. Also maybe improve the comparison by showing the two test cases side by side instead of flipping through them in the video :) In any case, this is a fantastic video. Waiting for more content!

[@elufo2321]

Thank you for this lesson. I love F1 or racing because is not just one person behind the wheel. Also i think a discusión of the actual air resistance and flow is important in this explanation but this is not tech talk. Thanks

[@lekkerreplekkertastic]

He’s back!

[@rickyaponte8399]

Awesome video Kyle💪🏻, thank you 👍🏼👏👏 Can you share a pressure color scale for reference? Also why vortex becomes an issue at some parts of the car but then purposely generated at some other sections?

[@martin_in_the_alps]

Please do the Mythbusters Golfball car, that would be great!

[@1BCamden]

Finally, thanks for this, more people need to subscribe to this channel and Racecar Engineering before communicating a personal assumption

[@chriswedgwood9673]

Part 2 please Kyle :)

[@thlee3]

that introductory graph made me sub

[@wayneedgaralphonso6675]

Like your videos mate :)

[@toshictoshic]

Great video, thank you! You said about the transcient effects. Could movement of the tunnel itself could cause flow separation because of change in angle of attack? I guess it could be several degrees while moving down vs moving up during the porpoising.

[@motojojo_]

With the bit @22:08 I'm guessing this is why we saw the various stays being used on the floors. Guessing Mercedes designed for maximum downforce with what they thought would be an acceptable level of porpoising. However they weren't able to forsee it hitting a natural frequency in the chassis. Wonder if Ferraris front wing design was done so it would give clean flow to the floor and reduce the size of the vortex heading into the underside. Interesting video as always 👍

[@tommihommi1]

I never thought about hysteresis in aerodynamics at all!

[@truegret7778]

Great breakdown. A very complex issue indeed. I am curious whether there is benefit to having a pressure characteristic to the large volume near the skate or region where the diffusor main body meets the corner vortices and edge vortices along the floor that acts like a "spring-damper".

[@olivert.7192]

wow this is really interesting

[@connarcomstock161]

AAAAAAAAA THE VIDEO I WAS WISHING FOR!

[@bennyz1971]

Really interesting video, well done👍🏻👍🏻 I wish to see a video about improving the aerosynamics of a Caterham 7 😉😁

[@sonicstep]

That car panders toward a particular niche market. If it aint broke, don't fix it.!

[@stefanroseEP3]

Quality video

[@crunks420]

When you said "histeresis" I had to check to make sure this wasn't listed on April 1st. Interesting video, though. Tks.

[@tensevo]

it would be nice to see where the section is cutting in the side view, also, where model available to download. with much thankss

[@mikeludacris3894]

A nice informative video, can you please share the CAD model of the car??

[@zlm001]

The way everyone was explaining it made it seem so simple to solve when obviously there had to be more to it.

[@dsdy1205]

Ladies and gentlemen, THE porpoising explanation.

[@manuelfischer9603]

Hi, great video. Which CFD software are you using?

[@cben86]

Great video. Do F1 cars not use position sensitive damping or is it just not sensitive enough to counter the strong rebound on a bumpstop?

[@filippobresciani5322]

Hey Kyle,can u upload the .foam file of the cfd analysis?(I just want to see it in paraview )

[@janmeyer2772]

Hi Kyle, very interesting and instructive video. Could you maybe do an analysis about the Porsche 919 Hybrid Evo? Even though it is already three years old, that car is, in my opinion, astonishing fast, as it broke the record on the Nuerburgring Nordschleife by far and even was faster than a F1 car in Spa. And because of the sideskirts, I think they are also using the ground effect, but why isn't porpoising a problem there? Would be very nice to see the details of this car explained.

[@nicholasabate5538]

As you’re going through the cut sections at the rear, you mention the vortices causing losses and therefore back pressure. Is that related to viscous forces slowing the air down, or inherently from turbulent behavior?

[@stevenanthony578]

FWIW... you showed how the RB floor generates lots of different vortices with various elements--some smaller than others. I wonder if the range in sizes act to kind of take over for another when it breaks down. So, as the the primary vortex starts to fail as the floor lowers, a smaller ones fill in the gap--and as the floor lowers more, causing that vortex to fail, a still smaller one seals off the floor. So you get a constant seal effect over a greater change in floor height, and thus, less oscillation. On the reverse direction (the RB does oscillate a bit), the floor recovers sooner as one of the smaller vortices comes back. The net effect would be it takes longer for the RB to stall out completely, and it recovers sooner.

[@telmoprego9658]

Hi, I’m interested in where you found the model and how you prepared it for the analysis. I have a great .stl model but I can’t properly covert it to solid for my CFD simulation. Any suggestions? Thank you

[@MaxTheBest97]

Hi Kyle, what software are you using for this post processing?