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2021 Williams F1 Computational Fluid Dynamics
- liamkinne 5y agoI still can’t believe Williams slipped up by putting such a detailed model of the car in the app.
- snypher 5y agoDo you know any more details about the leak? The article didn't really discuss it.
- psidex 5y agohttps://www.google.com/search?q=Williams+AR+app&tbm=nws https://www.google.com/search?q=Williams+AR+app&tbm=nws https://www.reddit.com/r/formula1/comments/lxaihc/behold_the_new_fw43b_3d_model/gplxdjj/ https://www.reddit.com/r/formula1/comments/lxaihc/behold_the... https://www.reddit.com/r/formula1/comments/lxaihc/behold_the_new_fw43b_3d_model/gpmet08/ 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 5y ago[deleted]
- mhh__ 5y agoThe regs are changing anyway so the risk is basically zero even if they had something worth stealing.
- golemiprague 5y agoThey 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
- kalal 5y agoSince 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 5y agoIt 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 5y agoWilliams engine is supplied by Mercedes, tires are shared from Pirelli. But sure there are other parameters as well apart from aerodynamics.
- cmsparks 5y agoOne 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.
- jsmith99 5y agoThe 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_cpus_in_formula_1_how_amd_boosted_ferrari/ https://www.reddit.com/r/formula1/comments/g4sboe/custom_cpu...
- deleted 5y ago[deleted]
- londons_explore 5y agoStrategy: Leak CAD model, get other people to do simulations for free!
- mhh__ 5y agoUnfortunately 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.
- 5y ago
- GoOnThenDoTell 5y agoI 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
- mhh__ 5y agoA million times this. Honda published a teeny bit of data in the mid 2000s but that's basically it
- KMag 5y agoSpeaking 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__ 5y agoTyre data is literally worth its weight in gold unfortunately
- KMag 5y ago> 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 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.
- kalal 5y agoI was wondering, how much different the simulation would be from stock models from Turbosquid: https://www.turbosquid.com/3d-models/formula-1-season-2020-3d-1534325 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 5y agoAgreed, 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.
- johnsonmd 5y agoDoes 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.
- kalal 5y agoIf 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 5y agoPerhaps a kind soul could implement an OCR system to extract data from the timing screen and make that available via an unofficial API :)
- mhh__ 5y agoYou 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.
- BozeWolf 5y agoI 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-tegelijk-kijken-met-de-race-control-app.html https://tweakers.net/reviews/8900/naar-diverse-f1-streams-te... (dutch) 2. https://github.com/robvdpol/RaceControl https://github.com/robvdpol/RaceControl
- kalal 5y ago> "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 5y agoYou 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.
- choeger 5y agoi 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 5y agoUnder what authority / jurisdiction would the author get in trouble for doing these computations? Surely the FIA doesn't have any authority over random civilians.
- deleted 5y ago[deleted]
- jonplackett 5y agoThe 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?
- choeger 5y agoThis year's rule change is about reducing downforce and so slowing cars down to protect the tires. Next year is about following.
- 2wrist 5y agoThe 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 5y agoOh, I thought these were leaks of the year after. Never mind then!
- gripfx 5y agoAs 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 5y agoVery 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.
- helmholtz 5y agoIt's "Colourful Fluid Dynamics" for a reason.
- JorgeGT 5y ago"Colors For Directors", especially without the grid and turbulence modelling (RANS? DES? LES?) data.
- johnbrodie 5y agoNot entirely correct, here's an interesting YouTube channel by an ex-F1 aero engineer: https://www.youtube.com/user/Kyleengineers 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.
- bernulli 5y agoCan’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.
- exDM69 5y agoThis 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 https://www.youtube.com/watch?v=ZlDnd3B1rhs
- Serow225 5y agoThat's an awesome video clip, thanks for sharing :)
- slowwriter 5y agoFor 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.
- zachrose 5y agoIt 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 5y agoThat 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 5y agoSimilarly, 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 5y agoI 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 5y agoAnother 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.
- bhouston 5y agoDo 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.
- bitL 5y agoBased 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.
- wouterremmerie 5y agoVery 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-the-adjoint-cfd-method/cZAhPQFINZ8 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.
- jdish 5y agoBox Box!
- jdish 5y agoBox, Box!
- kingsuper20 5y agoThe 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.
- _carbyau_ 5y agoDepends what you want from a series I guess. I see F1 as high budget soap-opera/reality-TV with a racing series setting. I can't relate to the people in the same way as you might with the "dirty dozen" approach but the drama is there nonetheless. I used to love F1 as an engineering research unit for the world. But once regulations started banning technologies - and even relatively simple tweaks! - left right and centre it lost that shine. I wish F1 would largely throw away the regulations again. Keep general safety regulations, a safety cell and 4 wheels, set the physical parameters for the car like size and weight with an 80kg driver, maybe specify some aerodynamic condition for trailing air and limit the unobtanium material use. I think limiting $ spent should be done by full specifications of cars to be released after 3-5 years. It is only worth spending money to get an advantage. If all your competitors are going to have your research in a few years then why spend so much? Also, ALL the engineering fanciness is released for the world to benefit. Then, when cars get too fast. Reduce the size/weight of the car, while keeping safety cell and wheels the same. "Oh, your 2m wide car goes too fast? Try it next year at 0.8 the size." Eventually it will be go-karts again. But of the most brilliant engineering.
- dgritsko 5y agoTo 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 5y agoTo 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.
- avereveard 5y agothe 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-aerodynamics/ https://maxtayloraero.wordpress.com/2020/12/15/mvrc-2020-f1-...
- bananabiscuit 5y agoI 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.