The largest open-source dataset of car designs, including their aerodynamics
news.mit.edu
news.mit.edu
Issue tracking at: https://github.com/Mohamedelrefaie/DrivAerNet
> Please note the (CC BY-NC 4.0) license terms, as outlined in the License section.
In spite of the title and the article says "open souce" many times, it's free as in "source abailable".
The watering down of the legal definitions of Open Source and Creative Commons is a death of a thousand cuts. Every single misrepresentation and false claim needs to be called out and shut down. It's hard to stress how important these concepts are to the current state of the world. Many people say "stop being pedantic" or "the source can be read, therefore it's open source". The reason you currently have a secure server operating system that can use state of the art encryption on affordable commodity hardware is that "Open Source" has a legal definition. Please, let's not break it.
There is no open source license (that I know of) which requires public availability. If there is a requirement of providing sources, it's always a requirement of providing sources with a derived work. If you are not releasing derived works to anyone you don't need to release any source to anyone either. So called permissive licenses don't even have any requirement on providing sources whatsoever.
Nevertheless, not every license is open source, open source does have a definition, and it's not about whether the owner is following their own license.
I meant < 0.20 of course, such as the 0.19 achieved by the ill-fated https://en.wikipedia.org/wiki/General_Motors_EV1
Electric cars need large, massive batteries to have a useful range.
It's as simple as those two things.
Then buy an ICE vehicle. It's a more mature, cost-effective, and power/energy-dense technology
My ICE car is 1300kg and it can drive ~1000km with a full tank of 62 liters.
This is true and also misleading since much more of the energy stored in gasoline is unavailable for conversion to work relative to an electrical battery. Additionally, an electrical battery can absorb some of the vehicle's kinetic energy, which a vehicle with only an ICE cannot do.
Maybe stop being an ass and try to be useful?
Now on top of that add that it costs significantly more and you have what is, by at least the metric above, an objectively worse product for a higher price. Yes, there are other advantages but limited range is a much bigger deal for flying than it is for driving.
Those new electric cars need big batteries just to be somehow usable. Recently consumed 35 kWh for 65 miles ride on model Y with trailer in cold weather. That makes <150 miles total winter range with trailer with fully charged battery.
If you want a small EV what about;
Dacia Spring Electric
Leapmotor T03
Citroen e-C3
Vauxhall Frontera
Vauxhall Corsa
The list goes on. Renault 5 E-Tech
VW id.2 all
It's smaller than the ID.4 so fits in our small garage, great turning radius which is nice in the city, and physical buttons for the most important stuff like climate and media. It can tow up to 900kg and supports a roof rack.
YMMV and such.
[1]: https://ev-database.org/car/1521/Renault-Megane-E-Tech-EV60-...
[2]: https://cdn.group.renault.com/ren/gb/transversal-assets/broc...
Unlike the Kia Nero EV and Hyundai Kona, two similar competitors, the Megane e-Tech was designed to be 100% BEV from the start, which I think is advantageous for an EV.
I'd say worth a look.
Compare my Mazda 6 wagon to the Mazda CX-9 crossover. My wagon is almost 25% more fuel efficient (7L/100km vs 9L/100km) but also has MUCH more space. Minimum cargo space of 506L vs 230L. Maximum cargo space of 1648L vs 810L. It has a shorter wheelbase and smaller turning radius. It does have worse towing 550kg vs 750kg but I almost never see anyone towing anything.
In Toyota's lineup the RAV4 is basically a tall Camry, and in Subaru's lineup the Outback kind of just got a bit taller and reclassified as a crossover alternative to the Legacy. Of course these companies all have larger and smaller options, but in general it seems like the adoption of larger vehicles is not because smaller ones aren't available, it's because for various reasons customers want to buy them. In any case worrying about exactly what vehicle mix is selling to me feels like rearranging deck chairs on the Titanic.
But that’s great news, if there’s truly a gap in the famously difficult automotive market, maybe a scrappy new player can break through with a simple, small sedan—one that can be made cheaply, and sold affordably—and then their supply chain can be forced into a series of buy outs and hostile takeovers, creating the next generation of wealthy donors to political action groups. It’s the ciiiirrcle of liiiife etc..
The majority of people buy their cars used, but the car makers make the cars they can sell to the minority who buy new cars - and they have very different tastes. New car buyers like gadgets and they like SUVs.
If you don't need anything right now, don't feel any pressure to go out and buy something new. If you do, get whatever works for you, even if that is an ICE vehicle. Don't feel bad; you're doing what is best for your family.
But know that the "future" in EVs is likely closer than you think. Look at the Canoo vehicles - I'm not saying buy one, just look at it and think about the design. Look at the VW ID.Buzz. Again, don't buy one (it's an overpriced usability mess), just look at it and think about the design. You know what is most interesting about it? The length is a foot to a foot and a half less than the existing minivans on the market, but it has more interior room. That is interesting, isn't it?
Well, the Ford CEO said this in the Q2 2024 investor call [1]:
> ...Now when people hear about affordability and they think about small and unaffordable, I'd like to address that now. We are designing a super-efficient platform, leveraging innovation across our product development, supply chain, and manufacturing teams. With no engine or drivetrain, a smaller vehicle can have a much roomier package, actually the interior package of a class above with a small silhouette. That's a big advantage for customers versus ICE. And we're focusing on very differentiated vehicles priced under $40,000 or even $30,000.
And then in the Q3 2024 investor call [2]:
> we're deep into the design and engineering of our next-generation vehicles. Boy! are we excited about these coming out in the next few years. In 40 years in the industry, I've seen a lot of game-changer products, but the mid-sized electric pickup designed by our California team has got to be one of the most exciting. It's incredible package and consumer technology for a segment we know well. It matches the cost structure of any Chinese auto manufacturer building in Mexico in the future. How do we know that? Because 60% of the [BOM] (ph) has already been quoted.
So, this pickup is the first one to come out, and that's not what you are looking for. But the EVs that come after it may be exactly what you are looking for. And of course Ford is not going to be alone. All the car companies are going to be working from this point of view. So, can you wait 4-5 years for the EV that actually works for what you need? Perhaps your next ICE car is your last ICE car?
[1] https://www.fool.com/earnings/call-transcripts/2024/07/24/fo...
[2] https://seekingalpha.com/article/4730242-ford-motor-company-...
The weight is just a consequence of current battery technology- no way to get that down much without hurting the range.
Look at Aptera motors for an ultralight efficient EV.
* Styling & consumer preferences. The SUV reigns supreme. Partly because of CAFE's perverse incentives.
* CAFE isn't directly forcing anyone to optimize EVs, and "watt hours per mile" is not widely demanded by consumers, because EV charging is ~40% the cost of gas per mile and because EVs are still exclusively a mid to upmarket thing. Everybody penny pinching is driving a 2003 Toyota with >100k miles which has appreciated in value over the past five years.
I wish it weren't so, but the revealed preference of the median car buyer is to simply buy as much car by the ton as they can afford.
Part of it feels like an arms race played out on the road as well. I finally had to buy a new[er] car after my 2001 Volvo wagon died. Modern cars are massive, heavy, and have shit visibility. They also have surprisingly similar or even smaller interior volumes compared to similar exterior sozed cars of 15+ years ago. But let me tell you, test driving even like a modern RAV4 (not a huge car by modern standards) made me feel like a prince on the road compared to my low ride wagon. Didnt feel like every other car on the road could run me over without noticing either.
Seems like cars will just keep growing til they hit the limit of roads, parking lots, and garages?
And that domestic market seeking overseas sales is shaped by CAFE, which in combination with manufacturing conditions has almost prohibited them from making the sort of small pickup trucks favored by the entire world before CAFE, and which remains common in the rest of the world. Sedans, minivans, even the tradesman's current best option in light commercial vans, are barely produced domestically anymore in comparison to the Lifestyle Truck, a thing which we gradually invented sometimes between 1980 and 2010 out of enclosure of small pickups, then the Soccer Mom replacing the minivan with a more vertically inclined Isuzu, then the Army HMMWV, then the F-150 and everything else just inflating in size annually.
CAFE's min-max optimization is why every marketing executive in the sector wants you to adopt an offroading hobby. That seeps out. Cultural export.
Modern highway safety standards also tend to increase the hight of windows which tend to also make cars taller to not kill visibility. Look at the 2019 Mazda 3 AWD redesign, especially the hatchback. It looks squished compared to the previous years because they didn't raise the vehicle height, but all the windows start higher in the car body. That trend is true of ICE vehicles as well though.
The range of both depend on if you drive in cold weather and if you drive on a highway. I bought and E-golf in 2017 that I drove long distance once on the highway when it was -20C (-4F). I then got around one hour of driving and one hour of charging... Do not recommend!
If you want more stats about the cars, this webpage is great:
2014 version: https://ev-database.org/car/1040/Volkswagen-e-Golf
2017 version: https://ev-database.org/car/1087/Volkswagen-e-Golf
weight is somewhat compensated by recuperation and a consequence of necessary battery weight for desired capacity / travel reach.
and while wind resistance depends on shape and "front area", front area actually is the cross section surface, the silhouette if you wish, as seen from back or front.
thus a teardrop like shape has a large flat part at the front but still it has near perfect, lowest resistance.
EVs reduce their front silhouette ("area") with a narrower cabin, low overall height, cameras as mirrors on vans.
thats how you reduce "front area" silhouette.
the shape of these is aerodynamic AF
https://web.archive.org/web/20240000000000*/http://www.yanfa...
Even for a finicky flying wing, I think if you keep an eye on the way the pitching moment shifts with pitch, I don’t see why picking an airfoil shape for the frame and hand calcs couldn’t get you to a design that flies reasonably.
Some good ones to look at to get started with nice guis
- VSP Aero
- XFOIL (for 2D airfoil analysis only, also generates inputs for 3D VLM solvers)
- AVL
And some others if you want perhaps a little higher fidelity, and don't mind text/code interfaces:
-FreeWake
- Datcom (not technically a potential flow models, but a database)
To get the most value out of these softwares, you will need some background in aeronautics. You need to have an understanding of what a potential flow models can and cannot accurately model. It also helps to have knowledge about what forms aircraft stability/control and performance data is typically communicated in, as these softwares will use that terminology.
However, the 3D tools above give you a little bit more, that I feel warrant their consideration by the op. These models can yield performance of wing-tail-body configurations that include wake effects. They also can give stability analysis in both longitudinal/lateral axes. The stability effects being especially important if OP wants to design a flying-wing, which are a tad more challenging to get right than just slapping a "good-enough" sized tail on a classic config plane.
I've used neither but I hear others in the gliding and model airplane scene talk about those.
I wouldn't mind if there were only a handful of designs around with some tweaks depending on performance/comfort. Also, nowadays many different models share parts, like lights or rearview mirrors, showing there's a need for efficiency and scale bigger than the made-up need for fashionable cars.
Alternators, starters, ac compressors and so much more could just be small, medium, large, extra large.
The price would drop dramatically.
Aaaaand, that's why they aren't modular. Take a look at something with obvious common parts like a side mirror. They are all intentionally designed adding special shapes to make them as unique as possible to the car. Never a simple square or rectangle.
I agree that many parts can be interchangeable but modularity can be done in a way that doesn't result in every car looking like the blobs we see about today. I wouldn't mind if there were only a handful of designs around with slight variations in trim and specs -so long as I like those designs of course! I know that is subjective so lets keep things interesting and focus on making things that get the job done but also in varying styles. Both can be achieved.
The need for fashion is made up, yes- but so is everything else. There's a balance between overly individualistic cars and the most cost efficient, reliable and uninspiring 4 door. Lately we have been leaning too far into the latter.
Think about every GPU having 8GB VRAM. Nobody wants that.
Business don't want standards because they care about selling non-practical bits of the car for a price, like how good it can make you feel because you think it's cool, even if it's dumb (dummy exhausts, fake carbon, LED logos and fashion oriented design)
A few cars have got it right after Saturn. I would say the Hyundai Veloster and Tesla Model 3 top that list.
It's funny, this is the second comment that I mention Tesla and Hyundai together. Two very different companies - entertaining to find this overlap.
Non-commercial licenses are not open source.
That said since it isn't source code I think the end result is probably a bit different. Unless I misunderstand something you could still use the data to further a commercial venture. You just can't directly commercialize the dataset itself. Conceptually similar to using a GPL'd software tool as an end user while performing work on a proprietary project.
It doesn't seem like there would be any legal barrier to feeding the dataset into an algorithm and making use of the result (depending on the implementation details of the algorithm I suppose).