[HN Gopher] 2021 Williams F1 Computational Fluid Dynamics
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2021 Williams F1 Computational Fluid Dynamics
Author : reimertz
Score : 286 points
Date : 2021-04-26 02:01 UTC (21 hours ago)
(HTM) web link (maxtayloraero.wordpress.com)
(TXT) w3m dump (maxtayloraero.wordpress.com)
| johnsonmd wrote:
| Does anyone know of a (preferably free) API for live F1 timing
| data? I would love to put together a custom dashboard for races,
| but haven't been able to find a source for the data.
| BozeWolf wrote:
| I read an article[1] a while ago where some people made a
| dashboard with all streams and data. Never tried it though. The
| application is called race control and is opensource [2]. If
| the app is not what you mean, their reverse engineered api
| client might help?
|
| 1. https://tweakers.net/reviews/8900/naar-diverse-f1-streams-
| te... (dutch)
|
| 2. https://github.com/robvdpol/RaceControl
| mhh__ wrote:
| You can extract the data by sniffing the app's traffic, but
| it's not easily done.
|
| Live _timing_ isn 't that hard, live pseudo-telemetry like the
| app delivers is really hard.
|
| Also you ain't getting it for free unless you're super lucky -
| not that kind of industry. Ergast has non-live data, however.
| kalal wrote:
| If you subscribe to F1TV you get timing data in form of
| additional screen which you can view. Apart of that, there were
| several attempts in the past to extract timing data from from
| live streams, which stopped around 2016 when the API was
| changes. So to my knowledge, there is no free API for that. If
| there was payed version, I would be also interested, but I
| don't know about it either. The thing is that F1 considers this
| traditionally very sensitive information and is unlikely to
| make it public any time soon.
| pedrovhb wrote:
| Perhaps a kind soul could implement an OCR system to extract
| data from the timing screen and make that available via an
| unofficial API :)
| kalal wrote:
| I was wondering, how much different the simulation would be from
| stock models from Turbosquid:
| https://www.turbosquid.com/3d-models/formula-1-season-2020-3...
| The article mentions there were some problematic areas in the
| extracted model. So I am quite skeptical that the model is indeed
| more accurate than what you can easily get from legal sources.
| QuentinM wrote:
| Agreed, that definitely sounds fishy as hell.
|
| Organizations where the big $ is on intel property and R&D
| wouldn't be dumb enough to give the actual schematics to some
| random intern building an app. There are some serious security
| controls and mNDA around that data, for all internal parties,
| external parties and suppliers. Think about it, they must
| collaborate with dozens if not hundreds of parties to get to a
| finished products, and some amount of information must be
| circulating to achieve the purpose of their relationships. If
| those were to leak - they'd leak to the competitors first and
| it'd be a disaster for the entirety of the upcoming year(s) as
| the improvements tied to their new designs would now be
| considered available on all cars. It doesn't take two dummies
| to think about that, soooo.. to avoid losing hundreds of
| millions, what do you do as an organization? Data
| classification, risk assessments, tight security controls,
| procedures, and finally mNDAs for the instances when data do
| have to be shared.
|
| Furthermore, as it was pointed out on Reddit, the model appears
| to be made of parts that are valid for 2020 regulations, some
| parts for 2021.. in other words, it's just scrap.
| liamkinne wrote:
| I still can't believe Williams slipped up by putting such a
| detailed model of the car in the app.
| golemiprague wrote:
| They are more or less the slowest car, who is going to steal
| anything from them? Haas? When teams want to copy stuff they do
| it from Mercedes or Redbull
| mhh__ wrote:
| The regs are changing anyway so the risk is basically zero even
| if they had something worth stealing.
| snypher wrote:
| Do you know any more details about the leak? The article didn't
| really discuss it.
| psidex wrote:
| https://www.google.com/search?q=Williams+AR+app&tbm=nws
|
| https://www.reddit.com/r/formula1/comments/lxaihc/behold_the.
| ..
|
| https://www.reddit.com/r/formula1/comments/lxaihc/behold_the.
| ..
|
| It seems that Williams released an app to view the car /
| livery in AR but cancelled it after people managed to extract
| the model
| [deleted]
| kalal wrote:
| Since Williams defines the very bottom of the race grid, they
| don't have much to hide in terms of technology. So releasing a
| 3D model of their car in this form is nothing that would harm
| the team at this time.
| nine_k wrote:
| It is possible that their aerodynamics are good or even best
| of all F1, while the motor, the suspension, the tires, etc
| lag enough to nullify this advantage.
| kalal wrote:
| Williams engine is supplied by Mercedes, tires are shared
| from Pirelli. But sure there are other parameters as well
| apart from aerodynamics.
| gripfx wrote:
| As someone in the industry, please take these numbers with the
| biggest grain of salt you can find. The writer has both added
| their own components and not divulged the CFD settings used.
| Which is fair enough but the numbers shown could be within 10% or
| 1000% percent of a "ballpark".
| timpattinson wrote:
| Very cool, but yeah anyone with the competency and computing
| power to do actually decent F1 CFD wouldn't be posting it on
| the internet.
|
| The teams themselves have a hard enough time getting a model to
| match their actual car.
| johnbrodie wrote:
| Not entirely correct, here's an interesting YouTube channel
| by an ex-F1 aero engineer:
| https://www.youtube.com/user/Kyleengineers
|
| You're correct insomuch as he's not sharing CFD settings, and
| is bound by what I assume is a pretty strict NDA, but he
| still has a ton of useful content. Of course, if you want his
| true opinion/skills on something specific, he'll do so for a
| price.
| helmholtz wrote:
| It's "Colourful Fluid Dynamics" for a reason.
| JorgeGT wrote:
| "Colors For Directors", especially without the grid and
| turbulence modelling (RANS? DES? LES?) data.
| bernulli wrote:
| Can't upvote this enough. I actually include an hour of rant in
| my Fluids class where we dissect CFD results from blogs or
| LinkedIn - hypersonic reindeer for Christmas are fun and
| obviously a joke, but everything presented sincerely, like all
| the Cybertruck analyses when it was revealed, are mostly
| irrelevant. Don't trust CFD results if you don't know every
| aspect of them.
|
| It's "dangerous" now in the sense that people just have to
| click a button and are led to believe that meaningful results
| are being produced without a thorough study.
| [deleted]
| kingsuper20 wrote:
| The Netflix series on F1 got me interested in the current rule
| sets and it's mostly just kind of depressing.
|
| It occurred to me that a professional racing series becomes
| boring at about the time that the car isn't built by a dozen (or
| less) mechanic/fabricators in a commercial space at an airport.
| dgritsko wrote:
| To each their own perhaps, but I find F1 very exciting. Even
| despite Mercedes's recent dominance, there is plenty of great
| midfield action, strategic decisions, uncertainty due to safety
| cars or weather, and teammate battles that make each race a fun
| watch.
| kingsuper20 wrote:
| To be fair, scarcely any HN readers (and a vanishing amount
| of the general population) remembers when racing hadn't gone
| down the rabbit-hole of infinite cost and technology.
|
| The post-war period of extremely common amateur racing
| morphed into pro racing some time ago. Most organized series
| became impossible for the dozen-guys-in-a-garage to compete
| probably sometime in the 1980s. We'll never see the likes of
| the Herb Adams 'Grey Ghost', Smokey Yunick small block
| Chevrolet Indy car, or (I suppose) Hesketh ever again.
|
| Like most endeavors in the era of mass media consumption and
| mass production/distribution, you end up with a handful of
| utterly dominant players with everyone else simply a
| consumer.
| cmsparks wrote:
| One note about the aero research rules in F1 which makes this
| post particularly interesting: there are limitations on the
| amount of CFD simulation time teams can use.
| quux wrote:
| Ironically, the allowance for CFD time is scaled based on the
| reversed world championship points order, and Williams was dead
| last, so they should have the most CFD time of any of the F1
| teams.
| kalal wrote:
| Interesting point, which a little bit implies that Williams
| would have the best aerodynamics by now. But clearly that is
| still not the case. So I am quite skeptical, whether CFD time
| has indeed the effect it aims to have. We all know that
| knowledge which you build up over time as a developer pays in
| long term. So even thou teams like Mercedes may have shorter
| time for CFD, they have the knowledge base build up over time
| which they use heavily.
| mkoubaa wrote:
| Exactly CFD time does not necessarily correlate to
| effectiveness. The saying "all models are wrong but some
| models are useful" definitely applies and if you make
| incorrect assumptions your CFD will not be that usefel
| pionar wrote:
| That rule was only implemented this year, so there is no
| data on that yet.
| BadOakOx wrote:
| Also, keep in mind that this year the rule is only in a
| demo mode. The first team has 90%, the last team has 112.5%
| of the dedicated time. From the next year this will change
| to 70% and 115%. (The time for the teams between is defined
| in steps of 2.5% this year, next year 5%)
|
| https://www.formula1.com/en/latest/article.how-f1s-new-
| slidi...
| jsmith99 wrote:
| The limit is in FLOPS but CFD is memory bound. To get round the
| limit, AMD made custom CPUs with restricted floating point
| performance to allow quadrupling the number of cores.
|
| https://www.reddit.com/r/formula1/comments/g4sboe/custom_cpu...
| gripfx wrote:
| That was awhile back. The rules have since been updated to be
| more flexible. AMD now has a multi-year partnership with
| Mercedes F1
| mkoubaa wrote:
| And now there are some CFD solvers that can use the GPU
| effectively
| [deleted]
| londons_explore wrote:
| Strategy:
|
| Leak CAD model, get other people to do simulations for free!
| choeger wrote:
| You can be certain that Williams' competitors will have a
| very close look at this leak. The regulations were written
| with such loopholes in mind.
| swarnie_ wrote:
| Why would you study one of the worst cars on the grid? For
| a laugh at the Christmas party?
| choeger wrote:
| If Williams outsourced their CFD with that leak, they
| might gain an unduly advantage over teams like Haas or
| Alfa. These teams compete over several millions in price
| money.
| Havoc wrote:
| Even a bad car might have a lesson or two in it
| FridayoLeary wrote:
| it probably still a lot faster then a volkswagen golf.
| More like a wild spin on New Years'...
| bitL wrote:
| It's not a leaked model, it was a 3D model grabbed from
| some mobile game...
| toss1 wrote:
| Seems you mean an attempt at open-source F1 car
| development...
|
| Plausible? With insufficient contributors, pace of
| development would be too slow
|
| With many, the big problem is sorting/selcting the most
| useful insights from the lot, but then that is probably not
| unlike any large org enterprise
| mhh__ wrote:
| Unfortunately doing CFD is not a question of running ./cfd
| carmodel and waiting for a day. You need to ensure you are
| correlated with real life i.e. the wind tunnel.
| TeMPOraL wrote:
| "Accidentally" leak the wndtnl-cor-current (1).csv file as
| well :).
| londons_explore wrote:
| Is that limitation to reduce the cost of competing for those
| who don't have big GPU farms?
| mlyle wrote:
| Everyone has tons of resources / big GPU farms / etc in F1.
| It's one of many limitations to stop the cost to be
| competitive from going to infinity.
|
| Typical contender teams spend $300m/year.
| bhoflack wrote:
| Since this year the budget cap for the teams is set to
| $145m/year.
| dgritsko wrote:
| Yes, but that comes with a pretty heavy asterisk - driver
| salaries are not included in the cap for example (which
| will be extremely significant for the top teams), nor is
| marketing. Still, I think it's a step in the right
| direction for the sport - having a cost cap in place now
| lays the groundwork for tighter restrictions in the
| future.
| peteretep wrote:
| What is a typical team? Biggest teams spend $450m, smallest
| spend $130m. The resource difference is very real, and the
| mean hides that.
| qeternity wrote:
| As another comment mentions above, there are now budget
| caps, which affect every decision a team make. For
| instance, one of the Mercedes drivers had a really nasty
| crash recently and the cost to build him a new car is
| putting budget pressure on Merc.
| AnthonBerg wrote:
| This reminds me of the invented sport Paced Badminton.
| It's badminton, and also the players have pacemakers and
| are only allowed a fixed number of heartbeats per match.
| KMnO4 wrote:
| IIRC it was mostly to reduce overall expenditure on
| aerodynamics. Before FIA restricted resources, teams would
| use wind tunnels 24/7, up to 70 days per year. This was crazy
| expensive so the restrictions were implemented (and they
| happened to include CFD limits too).
| fy20 wrote:
| How much did wind tunnels cost to build and run? I'm
| surprised the teams (or at least the parent company) didn't
| have their own dedicated wind tunnel.
| londons_explore wrote:
| A car size wind tunnel that can do 250 mph will be moving
| 400kg of air each second, and requiring a 2.5 megawatt
| fan. That costs ~$500k in electricity annually to run
| half a working day. That motor from China costs $30k.
| Imagine it's the same again for the fan, same again for
| wiring and control systems, and double that for
| fiberglass moulded side panels, foundations etc. We're
| talking PS150k, and that's for a very budget wind tunnel.
| nixgeek wrote:
| Working back from the $500k number gets me to 19 cents
| per kilowatt hour which seems a trifle high for
| industrial usage with a predictable 2.5MW load.
|
| https://www.gov.uk/government/statistical-data-sets/gas-
| and-...
|
| It looks like 14-17 cents per kilowatt hour is about the
| going rate as of Q3 - Q4 2020.
|
| I'm a little surprised this doesn't lead to more such
| facilities being strategically located based on
| availability of cheap power, e.g. by building near to
| hydro, and where power costs can be ~2c/kWh. See:
| https://www.seattletimes.com/business/technology/sunday-
| buzz...
|
| I'm forced to conclude the power costs are a marginal
| expenditure versus other costs involved in running such a
| facility, and benefits from having R&D, testing and
| validation, and production all on the same campus?
| exDM69 wrote:
| Most teams have their own dedicated wind tunnels and they
| are fairly expensive installations. As an example, the
| artificial lake you see in front of the McLaren
| Technology Center at Woking [0] is the cooling liquid
| reservoir for their wind tunnel.
|
| Check out this 8 part YouTube series from Sauber about
| their wind tunnel installation:
| https://www.youtube.com/watch?v=RBVgwpYUp18
|
| These are big industrial installations which need highly
| specialized staff to run them. Even if the facility
| exists, keeping the "wind on" costs a lot of money per
| hour.
|
| Ironically, as a response to the newly introduced cost
| cap measure, the teams are building new facilities like
| crazy right now, with many teams building a bigger wind
| tunnel so they can have it in the books before the
| accounting for the cost cap starts.
|
| [0]
| https://en.wikipedia.org/wiki/McLaren_Technology_Centre
| [1] https://www.youtube.com/watch?v=RBVgwpYUp18
| berkut wrote:
| Actually, the limit is in TFLOPs, and the use of CFD is
| audited.
| wiz21c wrote:
| How do they actually check the total hours of CPU usage ?
| gripfx wrote:
| Each team has to submit an audit of CFD runs at 8 week
| intervals throughout the year. An FIA inspector can also
| turn up on premise to review simulations run. The full
| details are in Appendix 8 of the sporting regulations [0].
|
| [0] https://www.fia.com/sites/default/files/2021_formula_1_
| sport...
| cepth wrote:
| In 2017, Ars Technica did a deep dive into computation in
| Formula 1
| (https://arstechnica.com/cars/2017/04/formula-1-technology/).
|
| Some relevant quotes:
|
| > For example, each Formula 1 team is only allowed to use 25
| teraflops (trillions of floating point operations per second)
| of double precision (64-bit) computing power for simulating car
| aerodynamics.
|
| > Oddly, the F1 regulations also stipulate that only CPUs can
| be used, not GPUs, and that teams must explicitly prove whether
| they're using AVX instructions or not. Without AVX, the FIA
| rates a single Sandy Bridge or Ivy Bridge CPU core at 4 flops;
| with AVX, each core is rated at 8 flops. Every team has to
| submit the exact specifications of their compute cluster to the
| FIA at the start of the season, and then a logfile after every
| eight weeks of ongoing testing.
|
| > Everest says that every team has its own on-premises hardware
| setup and that no one has yet moved to the cloud. There's no
| technical reason why the cloud can't be used for car
| aerodynamics simulations--and F1 teams are investigating such a
| possibility--but the aforementioned stringent CPU stipulations
| currently make it impossible. The result is that most F1 teams
| use a somewhat hybridised setup, with a local Linux cluster
| outputting aerodynamics data that informs the manufacturing of
| physical components, the details of which are kept in the
| cloud.
|
| > Wind tunnel usage is similarly restricted: F1 teams are only
| allowed 25 hours of "wind on" time per week to test new chassis
| designs. 10 years ago, in 2007, it was very different, says
| Everest: "There was no restriction on teraflops, no restriction
| on wind tunnel hours," continues Everest. "We had three shifts
| running the wind tunnel 24/7. It got to the point where a lot
| of teams were talking about building a second wind tunnel;
| Williams built a second tunnel.
|
| With the new cost cap in F1 (https://www.autoweek.com/racing/fo
| rmula-1/a35293542/f1-budge...) (which notably excludes driver
| salaries), it would be interesting to know how much these on-
| prem clusters cost to operate.
| Someone wrote:
| To level the field even more, I think the FIA should require
| teams to release the design of their computer hardware after
| X time. That way, investments by one team on improving the
| system architecture spread to teams with lower budgets after
| a while.
|
| Also, I didn't find it in the article, but I guess they have
| programmers who can work for months to speed up their
| software by a few percent.
| RaceWon wrote:
| >> to level the field even more, I think the FIA should
| require teams to release the design of their computer
| hardware after X time.
|
| But that is Not what Formula One is about... it is Not a
| Spec series where the cars are equal to each other. It is a
| competition where each team builds their own race car to
| compete against the other iterations of race cars built by
| the opposing teams. It is Not meant to be fair or
| equitable. We have Indycar and NASCAR for that.
|
| Ditto with the drivers: Is Max or Lewis comparable to say a
| Mazepin or even a Hulkenberg? No they are Not.
|
| It's a Spectacle, it's a Circus... that is what F1 is
| about. And I tell you, as a racer there is nothing else
| that is its equal in terms of pure audacity both from a
| standpoint of driving talent and car performance.
| capableweb wrote:
| F1 is definitely trying to make the teams and their
| engineering more similar than different, why do you think
| the whole regulation part exists even? [1] If they were
| to be allowed to build whatever they want, F1 would have
| looked very different than how it looks today.
|
| F1 (FIA really) has been using regulation to improve the
| sports safety, but lately they also used regulation in
| order to regulate how much each team spends on
| engineering, both money-wise and time-wise. This is to
| make things more equal between the teams.
|
| - [1] - https://en.wikipedia.org/wiki/Formula_One_regulat
| ions#Techni...
| RaceWon wrote:
| >> F1 is definitely trying to make the teams and their
| engineering more similar than different, why do you think
| the whole regulation part exists even?
|
| I agree, especially under the new owners. And for sure
| the cars are built according to each teams interpretation
| of the rules (which are of course subject to
| scrutineering). But that still leaves massive room for
| innovation.
|
| Lewis is sitting in the same cockpit as Bottas is...
| their results are frequently vastly different due to
| their individual interpretation of events.
| moralestapia wrote:
| >each Formula 1 team is only allowed to use 25 teraflops
|
| That ... doesn't make much sense, honestly.
| op03 wrote:
| What? How is that even enforced?
| mhh__ wrote:
| The onus is on the teams to prove it. If you cheat in formula
| 1 and they feel like punishing you a fine of one hundred
| million dollars is not unprecedented.
| avmich wrote:
| And nobody uses parallel construction?
| magicalhippo wrote:
| The difficulty of policing parallel construction was one
| of the key arguments against the cost-cap, IIRC.
| VBprogrammer wrote:
| Honestly, even without outright cheating, a manufacturer
| team has so many advantages it's kind of pointless.
|
| Imagine a scenario where a brake duct needs to be
| redesigned to account for some change in regulation or a
| performance tweak. At someone like Mercedes the
| conversation would probably start with ok, let's dig out
| all of the CFD we did for this when we designed this in
| 2007, let's also grab the data on the changes we made on
| the GP2 last year, also weren't the LeMans team doing
| some work on this last month? From there they would be in
| a much better place to identify the points where they
| have to concentrate their efforts without expending a
| minute of new CFD time.
|
| At a small new entrant team none of this data is
| available to them.
| fshbbdssbbgdd wrote:
| Guessing what you meant here if it wasn't obvious:
|
| A designer could have their own off-the-books compute
| cluster where they test out new ideas. Then only run the
| good ones on the official system.
| avereveard wrote:
| the suggested article in the series at the bottom is even more
| interesting, outlines a 'fantasy f1 championship' but for
| aereodinamicists to compete with their car concepts
|
| https://maxtayloraero.wordpress.com/2020/12/15/mvrc-2020-f1-...
| kalal wrote:
| > "I tried to match my lapsim program to telemetry from the 2020
| Spanish GP, I arrived at CL = -5.421 and CD = 1.150"
|
| This is very interesting. Does it mean that the author has access
| to 2020 Spanis GP telemetry from Williams?
| t0mas88 wrote:
| You can get quite detailed timing data from the F1 app. If you
| have the speed and time data for a sector that's completely
| full throttle and straight you can calculate quite a lot.
| exDM69 wrote:
| This is very interesting stuff. Look at the images labelled
| "velocity slice at ground plane" and "on the top side of the
| floor". You can clearly see the "Y250 Vortex" going between the
| front wheels and out around the barge boards.
|
| This vortex structure exists because the front wing main plane
| needs to be flat for +/- 250mm at on the Y axis from the center
| line. In order to get the outwash to the barge boards and around
| the rear wheels, the front wing needs to generate a huge vortex
| right where the wing starts.
|
| You can see the Y250 Vortex structure in this old footage from
| Mark Webber driving the RB9 in humid conditions where it forms a
| condensation trail as the air pressure drops:
| https://www.youtube.com/watch?v=ZlDnd3B1rhs
| Serow225 wrote:
| That's an awesome video clip, thanks for sharing :)
| bhouston wrote:
| Do you model this with spinning tires? That that make a
| difference? I would think that the amount of vortices, etc would
| be significantly different when the tires are in motion.
| choeger wrote:
| i think the author is aware of the trouble they could get into
| for doing realistic CFD on a current F1 car.
|
| > The only problematic geometry was the brake ducts which were in
| pretty bad shape, so I went ahead and made some simplified parts
| to replace them
| rocqua wrote:
| Under what authority / jurisdiction would the author get in
| trouble for doing these computations? Surely the FIA doesn't
| have any authority over random civilians.
| zachrose wrote:
| It seems to me that the aerodynamic picture of an F1 car would
| also have to account for all the air getting sucked into the
| engine and blown out the exhaust, no?
| djaychela wrote:
| That certainly was the case in the past with the whole 'blown
| diffuser' situation which led to cars' engine maps being
| specifically created to allow lots of volume of air through the
| exhausts even when they weren't generating much power to take
| advantage of this - listen to the exhaust sound in mid corner
| of this era F1 car and you'll hear what I mean (I think it was
| around 2011 and Red Bull were the best at it, but I think many
| did it to a degree).
| remus wrote:
| Similarly, a lot of the tricky aerodynamic effects in F1 come
| off the tyres (tyre squirt etc.) so without modelling those
| you're not getting a great view of the bigger picture.
|
| In a similar vein I remember reading that one of the reasons
| for the CFD restrictions was because the bigger teams were
| starting to spend a lot of money modelling the aerodynamics of
| the tyres as they oscillated in corners (because F1 tyres have
| a relatively high sidewall they deform a lot through corners,
| then if a wheel lifts a little e.g. bouncing over a curb, then
| the whole tyre starts oscillating laterally.) Sounds very
| interesting but a bit of a CFD nightmare!
| jcfrei wrote:
| I wonder if this is one of the reasons why they will switch
| to bigger rims in 2022. The explanation given was that the
| wheels would look more like those of road cars; making the
| cars more relatable to prospective car buyers I guess.
| Anyway, if you can reduce the side wobbling with larger rims
| then teams have it easier to meet the cost cap without having
| to spend money there.
| ARandumGuy wrote:
| Another justification I've heard for the larger rims is
| that the current, smaller rims make it difficult to make
| any meaningful adjustments to the car's suspension.
| Ideally, suspension adjustments will become a bigger part
| of the setup for each race, which could help differentiate
| teams that are able to get the ideal settings for each
| track.
| bitL wrote:
| Based on a Reddit thread, the model was 100% rigid - it would be
| interesting to see how the CFD changes when surfaces are allowed
| to bend and respond to different air densities at different
| spots.
| bananabiscuit wrote:
| I wonder if the computation was done taking into account that the
| wheels are rotating. I also wonder how much of a difference it
| would make in the output anyway.
| jonplackett wrote:
| The whole point of this year's new rules is to make it easier to
| follow the car in front.
|
| Do these simulations point to that being successful at all?
| 2wrist wrote:
| The pushed the new cars to next year, this year they wanted to
| cut downforce levels as the load was too much for the tyres
| last year.
| jonplackett wrote:
| Oh, I thought these were leaks of the year after. Never mind
| then!
| choeger wrote:
| This year's rule change is about reducing downforce and so
| slowing cars down to protect the tires. Next year is about
| following.
| wouterremmerie wrote:
| Very interesting! Some comments:
|
| CFD settings Indeed, without proper information on the CFD
| settings, it's difficult to judge the quality of these results.
| This includes: - Mesh resolution: smallest cell size, refinement
| strategy, ... - Mesh type: hexagonal? Prism layers? ... - Solver:
| which solver was used? Steady or unsteady? RANS or LES or ...?
| Were the results averaged? Were wall functions used? Y+ values? -
| Wheel rotation: which technique was used for wheel rotation? Just
| a "tangential wall velocity", or MRF, or a sliding mesh, or ...?
| Judging by the resolution of the flow pattern at the bottom, by
| the fact there is enough mesh to capture the details & gaps
| between wing elements, ... I'd say there is at least a decent
| amount of cells. But then again, that's just a very indirect
| estimation :)
|
| 3D model - Rake: the car is running at quite a high rake. This is
| just one of the "infinite" number of possible combinations for
| rear and front ride height and so on. So to get a full aero map,
| you would need to run the car at various positions. - Tyre
| compression: the tyres seem to have been cut-off at ground level,
| which is a common technique to add in the effect of compression.
| But the "height" of cut-off is subjective and has a large effect
| on the aerodynamics, as it influences the ride height and thus
| the underfloor aerodynamics. Also, there is no tyre deformation
| in the 3D model (or perhaps I missed it, difficult to tell from
| the screenshots).
|
| Analysis versus optimization This is an analysis, which tells us
| quite a lot. But it doesn't teach us how the team interprets
| results or, even better, how it translates this into improved
| designs. It would be cool to see how an adjoint solver would
| improve this car towards more downforce for example! (if you
| don't know what adjoint is, check this video -
| https://airshaper.com/videos/aerodynamic-shape-optimization-...).
|
| Overall, I find it very interesting - even if the model, CFD
| setup, ... aren't an exact match with what the guys at Williams
| are doing, it does provide a lot of interesting insight into
| existing flow structures on such cars - which is an interesting
| tool for learning.
| slowwriter wrote:
| For anyone that follows F1 it's not a surprise that the numbers
| show a draggy car, although they might be higher than the real
| ones. For three seasons now, high drag to downforce ratio has
| been Williams' no. 1 problem.
| jdish wrote:
| Box Box!
| jdish wrote:
| Box, Box!
| GoOnThenDoTell wrote:
| I wish they'd release all data for currentMinusX years ago.
|
| There could be so much fun playing with that data. Could make an
| accurate iRacing model, could compare teams historical downforce
| levels, could make tiny 3D models to paint
| m463 wrote:
| I remember reading a friend's "owner's manual" for a honda
| road-racing (only) motorcycle years ago and it was _amazing_.
|
| A normal motorcycle owner's manual is almost 100% propaganda by
| weight.
|
| it's basically legalese regarding injury, legalese regarding
| warranty type stuff, a few specificaitons, a bit of sort of
| fantasy maintenance which mostly segways into... "contact a
| dealer", then lists dealers
|
| In comparison the road-racing honda manual talked about
| reality. written by engineers, not lawyers.
|
| For example, I recall it told you how to gear the bike for
| different speeds (the kinds that would lose your license,
| wallet and prospects on the street)
|
| It also had carb (yes) settings for different track
| temperatures and all the maintenance intervals were in hours of
| use.
|
| I think this kind of stuff is a goldmine, and can really
| educate.
| baybal2 wrote:
| Are you into motorcycles?
|
| I've been recently thinking over a problem how to prevent
| squat on hub motor powered motorcycles/scooters.
|
| I would appreciate to know you think.
| chronolitus wrote:
| Right, this is true for the owner's manual. The service
| manual, on the other hand, is clearly written by engineers.
|
| Example:
| http://www.geersgonewild.com/z1000/Manuals/2007_Z1000.pdf
| Shorel wrote:
| iRacing? Nah, they will add it to rFactor2 and Assetto Corsa.
| 1_player wrote:
| Regulations always change and what was legal today might be
| banned tomorrow and be legal again (like Williams active
| suspensions from the Mansell era)
|
| It doesn't make sense to make all data public when there might
| be something the FIA or other teams didn't know about and might
| be useful in the future.
|
| F1 is all about living on the edge of what's allowed by the
| rules, and more often than not crossing that line and hoping
| not to get caught by the FIA. There's a fantastic interview
| with Ecclestone, Withing and Piquet (1) where they reminisce
| the olden days and have a laugh admitting their Brabham car was
| so illegal they would have been disqualified by the FIA had
| they knew that. 2019 Ferrari had an amazing engine and then
| they got caught doing tricks with the fuel sensors.
|
| 1: https://www.youtube.com/watch?v=fMsaUgXf3v4
| Someone wrote:
| It makes sense to release all data. Not for the teams, but
| for FIA. They could require teams to release it after some
| time, so that teams with smaller budgets can learn from the
| work done by teams with larger ones/better engineers.
|
| That would level the playing field a bit and, I guess, limit
| the amount of bending the rules (even if the FIA would give
| amnesty on any infringements found, which it probably should
| do)
| jacquesm wrote:
| Yes, but then you'd find that the FIA cut deals with teams
| in the past to wipe various infringements off the books so
| they wouldn't be embarrassed. Take for instance the way
| Ferrari performed after changing 'absolutely nothing' from
| one day to the next they were in the midfield or even at
| the tail. If they released everything it might show how
| Ferrari might have to hand in all of their points in 2020,
| and quite possibly 2019 as well. And/or be disqualified.
|
| F1 is a media circus, not a sport and 'fair' and 'level
| playing field' are things that are not on the books unless
| they happen to drive up the bottom line.
| RaceWon wrote:
| >> F1 is a media circus, not a sport
|
| I actually posted earlier that F1 is a "circus"... I
| agree. It is however a Very Real Sport insofar as the
| drivers are World Class Elite Athletes... especially the
| few who can run at the front.
| Gene_Parmesan wrote:
| Maybe, but the IP holders are never going to agree to this.
| You have not only the entrants themselves, but also engine
| manufacturers and so on. I really believe the manufacturers
| would leave the sport first; many of them are on a hair
| trigger anyways given the shift in consumer R&D to
| electric.
| mhh__ wrote:
| A million times this. Honda published a teeny bit of data in
| the mid 2000s but that's basically it
| KMag wrote:
| Speaking of Honda and 2000s, the S2000 engine is a pretty
| remarkable piece of engineering. It would be really
| interesting for them to publish data for a car that's
| reasonably obtainable on the used market. Both engine and
| aerodynamic fluid models would be interesting to play around
| with.
| mhh__ wrote:
| Tyre data is literally worth its weight in gold
| unfortunately
| KMag wrote:
| > Tyre data is literally worth its weight in gold
| unfortunately
|
| The minimum amount of energy to flip a bit at the
| temperature of the cosmic background radiation, converted
| to equivalent mass via E=MC^2, is minuscule. (The mass of
| a black hole with one bit of entropy at its surface is
| also minuscule.) So any data worth storing is literally
| worth several orders of magnitude more than its weight in
| gold (assuming the gold and the data are weighed under
| the same gravitational acceleration).
|
| http://scottkurowski.com/massbit/index.htm
|
| Edit: apparently people are taking my response as being
| more snarky than I intended. I just find it interesting
| that bits actually have mass. Information is incredibly
| expensive on a per-mass basis.
| ddingus wrote:
| I appreciate your comment and learned something new that
| is fun to think about.
| jacquesm wrote:
| You could modulate photons, they are massless.
| phonon wrote:
| It does have momentum though!
| KMag wrote:
| and distorts spacetime/generates gravity!
| KMag wrote:
| > You could modulate photons, they are massless.
|
| Photons have no resting mass, but my understanding that
| they still distort spacetime. It's not only mass that
| generates gravity. We're talking about weight, and it's
| mass-eneregy that warps spacetime/generates gravity.[0]
|
| My understanding is that none of the virtual interactions
| in the Feynman path integral for that photon traveling
| through spacetime (such as spontaneously becoming a
| particle-antiparticle pair) affect the far-field
| gravitational field generated by the photon.
|
| Also, 99% of the mass of your body is not electrons and
| quarks, but the binding energy between quarks. The mass
| of a proton is ~938 MeV/C^2, but the masses of its quarks
| sum to about 9 MeV/C^2. The rest of the proton's mass is
| the binding energy of the quarks. You get a similar ratio
| for the neutron. The electron's resting mass is roughly
| 0.5 MeV/C^2.
|
| I think the Higgs mechanism is responsible for the rest
| mass of quarks, leptons, and neutrinos, but the majority
| of mass in atoms is due to nuclear binding energy, not
| the Higgs mechanism.
|
| Though, my formal physics education didn't go beyond
| Freshman year E&M, so I could be way off.
|
| [0]
| https://van.physics.illinois.edu/QA/listing.php?id=28195
| mhh__ wrote:
| The tyres mass.
| KMag wrote:
| Thanks for the clarification. I think we all understood
| what you meant. A more literal interpretation just
| reminded me of a tidbit of physics I find very
| interesting.
| rlonn wrote:
| Previous commenter did write "literally". A word which,
| IMO, is ridiculously overused and abused by people with a
| bit of a chip on their shoulder. I'd say they asked for
| it! :)
| mhh__ wrote:
| My background is in physics (the tyres are a hobby), so
| maybe I was due.
|
| I immediately knew what the comment would be the moment I
| posted it but it's 6AM so I didn't bother being more
| precise.
|
| There's probably an information-theoretic framework to
| calculate the value of the data but who cares (Answer:
| Me, but again 6AM).
| FridayoLeary wrote:
| it took me time to get that. very clever.
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