World's most efficient and aerodynamic car

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Generator   100 mW

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World's most efficient and aerodynamic car

Post by Generator » Jun 14 2018 10:07pm

That's what the company is claiming. Does that mean they are better than Tesla, BYD, Faraday Future, Lucid Motors, Byton, BMW, Fisker, Mercedes, Nissan, Toyota and all other companies? I wonder how much efficiency you can improve, if you have the design as shown in the video https://www.youtube.com/watch?v=jvFnEyUFmI4

I tried to find more details on website at https://guru.run but haven't found much yet. Anybody have more insights about this car?

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Re: World's most efficient and aerodynamic car

Post by whereswally606 » Jun 15 2018 5:30am

Kind of laughable, the video claims no compromise on a lots of important factors in the car, But fails to mention that massive hole through the centre of the car axially. So you loose quite of a lot of cabin space. I think this is probably a joke rather than a serious design.
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Generator   100 mW

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Re: World's most efficient and aerodynamic car

Post by Generator » Jun 15 2018 8:28am

I actually see more cargo space than what other cars have and the cabin space is adjustable too, so we still get same cabin space, if required.
But my point of discussion is about efficiency and not the size as if you see Smart Car from https://www.smartusa.com only cramps 2 people in it and still have meager mileage for that size. Also https://www.eliomotors.com have only 3 wheels which I thought was Joke but its kind of successful company now.

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Re: World's most efficient and aerodynamic car

Post by billvon » Jun 15 2018 11:32am

Generator wrote:
Jun 14 2018 10:07pm
Anybody have more insights about this car?
Agree with the other poster; it's a joke. Any duct is high drag both due to interference of compression waves and greatly increased surface area.
--bill von

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Re: World's most efficient and aerodynamic car

Post by Generator » Jun 15 2018 12:10pm

billvon wrote:
Jun 15 2018 11:32am
Generator wrote:
Jun 14 2018 10:07pm
Anybody have more insights about this car?
Agree with the other poster; it's a joke. Any duct is high drag both due to interference of compression waves and greatly increased surface area.
Well they backed high efficiency claim based on simulation results, which is confusing to me.

Here is another one from Benz https://www.youtube.com/watch?v=xt2ZLbOUSwU

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Re: World's most efficient and aerodynamic car

Post by billvon » Jun 15 2018 12:18pm

Generator wrote:
Jun 15 2018 12:10pm
Well they backed high efficiency claim based on simulation results, which is confusing to me.
Simulations may well show more efficiency, depending on what the simulator is ignoring. (All simulators use shortcuts to speed execution time; one method is to not calculate certain parasitics if they are not deemed to be important.)
--bill von

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Re: World's most efficient and aerodynamic car

Post by Generator » Jun 17 2018 4:18pm

billvon wrote:
Jun 15 2018 12:18pm
Simulations may well show more efficiency, depending on what the simulator is ignoring. (All simulators use shortcuts to speed execution time; one method is to not calculate certain parasitics if they are not deemed to be important.)
Is there a way we can simulate it easily? Or you have the ability to do it with all factors included?

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Re: World's most efficient and aerodynamic car

Post by billvon » Jun 17 2018 4:21pm

Generator wrote:
Jun 17 2018 4:18pm
Is there a way we can simulate it easily? Or you have the ability to do it with all factors included?
Heck no. It takes me weeks to even accurately simulate a power converter with all the parasitics in the magnetics, switches and driving circuits. And simulating electronics is a lot easier than fluid dynamics.

Fortunately as computers become more powerful, more and more of the problem becomes amenable to simulation. 99% of a modern aircraft's design is tested through simulation now. But it's a long and _very_ expensive process to get it right.
--bill von

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Re: World's most efficient and aerodynamic car

Post by LiveandLetDrive » Jul 16 2018 6:39pm

Hi, EV aerothermal CFD engineer here. This looked like a fun place for my first post. Wow, where to start with this. CFD pet peeve: streamlines in isolation aren't engineering, they're PR fluff. Yes, a sufficiently large hole down the center of the car could decrease drag, but you'd be far better off just making it less wide! (Yes, ducts generally add drag, but that's because you're catching the air and accelerating it up to the car's speed, or nearly, and then dumping it. This thing is attempting not to do that, but will still be inefficient.) External downsizing, specifically on the sides, is what Elio and other pod-cars did, in the extreme. I wouldn't call them a "successful car company", I'd call them a niche manufacturer finding just enough oddballs(/optimistic investors) to stay alive. (Not that there's anything wrong with that.) All modern car designs are shrunk as much as they can to decrease frontal area to the limit of impinging on the occupant space or style intent. Punching a hole through the middle is just heavier for the same result. Being larger and having no structure through the hole area it must necessarily be heavier to be structurally sound. Weight is also critical for efficiency of course, especially with city driving or inclines. There's a reason twin-fuselage airplanes haven't become the norm, and only exist for very specialized uses: https://en.wikipedia.org/wiki/Twin-fuselage_aircraft

If he tried to make these from existing cars he'd find they're tightly and deliberately packaged with stuff in that area he wants to blow a hole through. In that Tesla specifically there's a center radiator, ducts, suspension and steering components, structure, *battery pack*, MOTOR!, huge HVAC unit and ducting, nevermind cargo and passenger space. There's nowhere else to put this stuff without just making everything about this idea even worse. Ironically enough, that Mercedes concept demonstrates that you can achieve a far better result managing the air outside the vehicle; you don't have to bore a hole through it. That concept isn't going into production because it'd be crazy-expensive but movable bodywork is increasingly on the road as they learn to make it cheaper, lighter, and reliable. It's usually more of a style thing as the aero gains just aren't huge without unmanageably huge mechanisms. And a tunnel you could ride a scooter through qualifies as an unmanageable mechanism!

The reason the drag is reduced compared to the Tesla S (which has great aero for its size) is that it simply isn't a comparable vehicle anymore! You can also strip out all the interior, cut off the roof, and replace the windshield with plexiglass to make a lighter and therefore more efficient car. But it isn't remotely in the same category of car anymore, and you could design a superior lightweight car from scratch than you will ever get by mangling a well thought out design after the fact. With a couple hours' work I could run CFD on a car shape, then again with a big hole down the center, but I won't because I can tell you with confidence that if you make the hole big enough it'll have less drag. This isn't a new idea, it just isn't applied at this scale because it makes a bad car.

There are countless practical reasons not to do this (and more why noone would buy it), but more to the point, this isn't a company, this is some rando with an undeveloped idea, access to (some form of) CFD, a loose grasp of video editing, and a YouTube account. I am certain this video exists only to drive clicks to those spam-y "partner websites". It's pretty hilarious he's offering options like a bed (#vanlife) and suggesting "get one today!" This is not the cart before the horse, it's a flaming cart tumbling down a mountain like a crashed car in an action movie. There never was a horse.

Car moves through air... air hits car and "wastes" energy... remove car and energy is saved!

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Re: World's most efficient and aerodynamic car

Post by X2flier » Jul 16 2018 10:19pm

.
Sorry, but that thing is NOT it. I don't buy it (literally or any other way). Some European super-cars look very aerodynamic, but the engines are not exactly economy models.

My personal vote would go to the plug-in hybrid Aptera, as being sleek and practical in real life. That is, if it is being produced commercially now.

Anybody have a better candidate than Aptera?

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Toorbough ULL-Zeveigh   10 MW

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Re: World's most efficient and aerodynamic car

Post by Toorbough ULL-Zeveigh » Jul 30 2018 9:58pm

LOTUS!

Kick down the barricades Listen what the kids say.
From time to time people change their minds But the Frock is here to stay.
I've seen it all from the bottom to the top Everywhere I go the kids wanna Frock.
Around the world or around the block Everywhere I go the kids wanna Frock.

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