Tribute to Syd Mead or F-117 aerodynamics?
 

Tesla Cybertruck!

https://i.kinja-img.com/gawker-media...9likoynycy.jpg

https://www.motortrend.com/uploads/s...ound%7C875:492

https://www.motortrend.com/uploads/s...ound%7C875:492

https://www.motortrend.com/uploads/s...ound%7C875:492

https://www.motortrend.com/uploads/s...ound%7C875:492

https://www.motortrend.com/uploads/s...ound%7C875:492

https://electrek.co/wp-content/uploa...y=82&strip=all

Inspired by Italdesign Giugaro's Lotus Espirit S1 or Gandini's Lancia Stratos Zero

https://img.pistonheads.com/Fullsize...S3623960-1.jpg

https://hips.hearstapps.com/roa.h-cd...p&resize=980:*

Cool.

The last time I experimented with such a shape it was a tandem two seater with outboard wheels, and a canopy that slid back so it was also a convertible. Drew 3 and 4 wheel versions, a mix between BF-109 and F-117.

The project prior to that was (30 years ago now?) was a 3rd world flat plane plywood car (just for fun) that I built a foam core model of.

The buttresses on this Tesla are rather first Gen Honda Ridgeline-ish, and I like that.

This is an angular pill to swallow but maybe what the doctor ordered?

I was fairly sure that the Tesla pickup was going to be a scaled down version of the Semi-Truck design, at least that the direction my own private sketches have been going for the last few years.

I suspect this Tesla has the military market in mind, and not so much civilian, why else the special unbreakable windows?

Tesla reveals Cybertruck, but breaks its 'unbreakable' windows during unveiling
https://www.cnn.com/2019/11/22/cars/...uck/index.html
https://cdn.cnn.com/cnnnext/dam/asse...xlarge-169.jpg
https://cdn.cnn.com/cnnnext/dam/asse...xlarge-169.jpg
To stay in business I suspect they will have to add $100,000 to those prices and become advanced scout vehicles for the world wide military market.

I could be wrong, but do not see this specialty item derailing any of the electric truck offerings and or plans on the near horizon.

Aerodynamically speaking, lots of drag from those wheel flares. I know this first hand and not just by looking at CFD images online because I've done stuff to my pickup truck.

I also expect a lot of flat plane rolling vortexes of which numerous diagrams have been posted in the forum over the years. That roof plane change isn't exactly a friendly transition.

From the Random Aerodynamic Oddity Thread:

Strouhal Numbers of Unsteady Flow Structures Around a Simplified Car Model
https://link.springer.com/chapter/10...642-40371-2_26
https://media.springernature.com/ori..._Fig5_HTML.gif
Flow structures in the near-wake of the Ahmed model
https://www.sciencedirect.com/scienc...89974605000514
https://ars.els-cdn.com/content/imag...000514-gr1.jpg

Yeesh. It's got errodynamics.

I bet they are counting on model X history to estimate the range. Unfortunately the Model X is aerodynamic so this thing is going to need twice the model X battery if not more to get those kinds of ranges with more frontal aera, terrible aerodynamics, and big off road tires.

False Flag operation and or testing public opinion of the military version on same platform intend for a scaled down Semi-Truck looking pickup truck?

http://forums.pelicanparts.com/uploa...1574451037.jpg

The above is from my Aerodynamic Folder in my computer, do not recall where I got it from but a reverse image search may lead you there.

Ok so I think one simple change would improve this both aesthetically and aerodynamically. Just flatten the roof. The peak just adds frontal aera and makes a tougher angle that forms eddies.

I'm going to dub the peak a Tesla "dunce cap"

https://ecomodder.com/forum/member-h...23-gallery.jpg

Tesla CyberTruck - Page 3 - Pelican Parts Forums
http://forums.pelicanparts.com/uploa...1574455248.jpg

Guess they don't understand rounded front corners on trailers either.

The front should be canted, not the rear - it's freaking backwards.

Sure, but just about every vehicle is designed this way nowadays, not with a sharp transition, but with a tapered and sloped transition. The whole reason it's peaked is that it maximized headroom in the driving position.

1st-gen Lara Croft finally has a Barbie Truck! https://i.imgur.com/EtiRpFY.jpg

Someone did a little more than that in this Photoshop and removed what little aerodynamic value there was.

Random TRANSPORTATION pictures - Page 2268 - Pelican Parts Forums
http://forums.pelicanparts.com/uploa...1574470945.jpg

Thanks for the inspirations by futurists/designers; Syd Mead, Bertone Design Milano, Gandini, Giugaro, etc

https://assets.hemmings.com/blog/wp-...dMead_1000.jpg

https://i.imgur.com/eJ6XL4N.jpg

https://i.imgur.com/NBcjqAr.jpg

https://i.imgur.com/Yd1gtoq.jpg

https://ia800702.us.archive.org/Book...ale=2&rotate=0

https://pbs.twimg.com/media/B9EOIeIIcAAs_yI.jpg

https://www.leblogauto.com/wp-conten...-Tapiro_21.jpg

There is a silly amount of headroom in the front. If there is enough for a 6'5" guy in the back seat, there is plenty in the front with a flat roof. They did it just to be extremely different.

It isn't clear to me that a flat roof would give the headroom they were targeting, or that going with a conventional curved radius is possible given the thickness and material they are working with.

Sure, they are going with straight lines as a theme, but it isn't clear if that was the design philosophy from the beginning, or if it's a consequence of the material and structural engineering choices.

Regardless, the problem with the appearance can't be fixed with a flat roof. It's a stark design, and most will hate it, and a few will love it.

I'd compare to the design evolution of that other vehicle made from the same material, the Star Ship. It has evolved through at least four distinct design phases (carbon fiber/stainless steel tanks, cable and pulley/elevator, etc.) and hasn't flown yet.

I expect some evolution. The design is constrained by the retractable tonneau cover. One simple improvement (not Photochopped yet) would be to give the tonneau a simple curvature. I appreciate the tailgate they stole for Gordon Murray's OX.

You'll be able to wear a ten-gallon hat in your pickup again.

The shape is constrained by the formability of the metal alloy. It needs 3D printed corners.

roof apex
 

What they've done might be a concession,enabling the tonneau cover to slide up into that region.The truck has the best sectional density in the market,albeit,with some mutilation.Separation,with re-attachment,but longitudinal vortices.1970's Bertone-meets-DeLorean.
With the truck 'dropped',we may be glimpsing Tesla passenger car silhouettes of the near future.With edge softening,they'll get below Cd 0.2.Easy!:)

Define sectional density?

sectional density
 

It's synonymous with area rule,where the body cross-section varies only gradually as a function of longitudinal location,ensuring no pressure or velocity spikes(Bernoulli's Theorem),which protects the turbulent boundary layer from counter-flow,eddy roll-up, separation,and turbulence; allowing pressure regain and a higher base pressure,mitigating pressure drag.
Tesla's sharp edges and sharp intersections could be improved upon,but the basic silhouette is quite a bit like a streamlined half-body.

The one they were giving rides in had a glass roof and the tonneau either wasn't installed at all or rolled up because you could see out the back window. It also didn't look like there was room between the top of the back window and the rear of the glass roof for it to be rolled up there. So either it rolls all the way up and then down lower than the back window or that prototype was tonneau less.

At least you don't have to guess if it would be better going forward or reverse as you can hardly tell.

By my 4" brass caliper (I had to zoom out three times) the peak is 45% of the length back. I believe the template has it at 30-some %. aerohead?

Modifying to a Ridgeline-style bed eliminates the retractable-in-flight feature. The peak would be a good place for a light bar.

edit: I tried again with a thumbnail on Youtube and got 42%.

2nd edit:
I watched a few more videos. The tonneau is a tambour that stores behind the rear seat, not over it. So the roof peak is an affectation.

It does have a light bar in the peak.

I was just reading on F117 aerodynamics. That think was built with two goals, stealth and the ability to fly. Aerodynamically it was a 50 year or more setback

In the case of the F-117 the constraint was modelling the radar reflections. Those things that replaced slide rules (computers) couldn't handle compound curves. By the time for the B-2 that had been sorted.

In the case of the Cybertruck, they're essentially trying to stamp out pieces made from spring steel.

Everybody is commenting — even Akkad Daily. He provides an assortment of memes (Baby Yoda showing his truck drawing to Elon in a cloud of smoke), but starts by showing his childhood favorite car from Total Recall and then ranting about the truck being ugly.

In contrast, the Tesla Cybertruck design was built with two goals; most 'visible' & distinctive vehicle profile ever and the ability to 'fly' Tesla into the most lucrative truck market!

What you are seeing is a revolution in manufacturability. Folding metal is cheaper than stamping it. No paint is cheaper than paint. Flat glass is cheaper than molded glass.

The high end Cybertruck gets you 500 mile range for $70K. The Roadster has more range but costs 3x. The low end Cybertruck costs as much as a Model 3 but carries six passengers instead of five.

The ease of manufacturing is still to be debated. This is Elon we are talking about. Remember the 3 piece wheel tub and that we are talking about making parts of some sort of stainless. Whole different forming and machine processes than cold roll.

A couple of one off's is very different than making 10,000 identical items in a short time.

More polygons in creating their truck
 

Low poly Karlmann King had a little bit more pieces to play with...

https://www.youtube.com/watch?time_c...ature=emb_logo

Cybertruck CFD
 

Are the boxy Tesla Cybertruck’s aerodynamics any good? An engineer found out

From his Facebook post about it:

Well, no one else did it so I did. Here is the #CyberTruck in CFD. What intrigues me is how well this works. While it may occur to be happenstance that the aero turns out quite well, I believe this was actually the result of very clever design. Ease of manufacturing in flat panels, significant use of triangulated body parts, etc. I won't quote a drag coefficient, as I dont want to put words in anyone's mouth, but I will place money on it being much lower than most sports cars, and any truck period. Further, I believe the vortex shed over the bed walls helps act to "seal the bed" when the cover is open. I havent modeled the open bed yet, but it sure seems promising. Further, it appears the front end is designed to almost entirely blank out / shield the wheel well.... The cad file is dimensionally correct, all angles and curves are as close as possible. There are some uncertainties such as fenders and wheel well air-exhaust etc.

Lastly, at 65mph the local velocity over the roof "peak" is 88mph. Is this the ultimate Elon Easter Egg?

Found out, and then shared the results with nobody. The article doesn't say how good the shape is.

I'm assuming it's pretty decent compared to typical truck design. Could be better with radiused curves instead of sharp ones, but maybe it didn't affect efficiency too severely.

November 2019
Chevrolet Corvette: We changed everything.
Ford Mustaing: Hold my beer.
Elon Musk: Hold my joint.

It amazes me how quickly I've got from an initial impression that the truck is hideous, to it kinda growing on me.

Maybe I'll buy one instead of a minivan if/when the family grows.

I'd call this a revolution in re aligning the market's expectations, accepting a vehicle that looks like the shoddiest third world kit car. Those ideas are not new - dozens of flat panel vehicles out there:

https://www.theverge.com/2016/9/11/1...mclaren-africa

My immediate thought was of these Hummer kits made locally a while back:

https://i.pinimg.com/originals/da/73...de24266157.jpg



Paint is cheaper than no paint, but stainless is more expensive than mild steel+paint. I'd say it's more about saving the time involved in painting to ramp up production more quickly, plus no paint issues like they had with the 3. There's talk of vinyl wraps which of course are very expensive and time consuming...

nobody
 

He says that his reason for not sharing the drag coefficient was,that he had a low confidence in accurately modeling of the wheel openings, and how that might impact drag.
My SWAG is sub-0.30.I got Spirit to maybe 0.218 with the boat-tail,and 0.297 without ,but as a BEV (sealed cooling inlet). I'll be very surprised if the Tesla comes in at over 0.3.And we know from the Porsche 914 wind tunnel testing what the influence ground clearance can make.The Cybertruck has an 'ideal' belly and in the 'lowered' position,could come in below most passenger cars.And with aftermarket add-ons,approaching the best concept cars.
It's a coup.And with mods,a coup de grace.:thumbup:

30-some %
 

Technically,the frontal area would occur at 1/3rd body length,then utilize the next 2/3rds for decelerative pressure-regain.That would be based upon the full-length body.From there,one could do any degree of truncation and still maintain the 'Kamm-Fachsenfeld' form.

ease of manufacturing
 

I've watched some programs on automotive manufacturing,and some of the body stamping operations required three different sets of tooling and separate operations in order to achieve the final degree of draw in the metal before clamping and robotic welding operations could commence.
I'm not a manufacturing engineer,but I suspect that their are inherent cost savings if body shaping operations can be limited to a single operation,even with quick-change dies as Fiat Chrysler uses in RAM pickup truck fabrication.
If hydro-forming is involved,the tooling would be a fraction of conventional tooling cost.Anyone with a subscription to Ward's Automotive will probably already know.

See, you were brave enough to take a guess without having done any CFD. The guy isn't worth mentioning if he isn't going to be bold enough to take a stab at it. Afterall, that's exactly what he did for his own curiosity.

If we needed 100% confidence in anything to make a prediction, we'd never get anywhere.

curiosity
 

I'm asking Santa to arrange for CAR and DRIVER's Don Sherman to put it in the AeroDyn wind tunnel (I think it's too much frontal area for the A2) in Mooresville,North Carolina,in 2021,and publish the Cd,as they already did for the Tesla Model S. Tesla has published Cds for all their vehicles so far,I presume they'll do it for the Cybertruck,once the production design is 'locked in.' The AeroDyn numbers would be a nice backup for the CFD which I presume Tesla will use again.
The NASCAR truck series better hope to ---l Tesla never enters the competition (with a quick-change pack).It's shape,alone,would sweep the field,as the Chrysler Charger Daytona did in the 60s.;)

Scott Adams was amazed too. It took him three days before he threw down his $100. I'm trying to convince my son to do that. In two years his Silverado will be paid down and his SRT-8 will have appreciated. I don't think he appreciates needing one less parking space.

oldtamiyaphile — Thanks for mentioning the Ox. There's also the VW Hormiga.

Thanks. I found out if you search for 'fashenfeld' you'll never find 'fachsenfeld'. I wanted that for the discussion of Peter Brock's Cobra Daytona Coupe. I think a key feature are the generous chamfers on the front corners.

Here's an article on edges: www.seattletimes.com/.../cutting-edge-aerodynamics-auto-designers-discover-surprising-new-things-about-saving-fuel/

Daytona
 

My geodesic dome-dwelling neighbor Bob,up the road, is friends with solar car and aircraft designer Larry Mauro,whom visits Bob from time to time.Larry's a many decades-old good friend of Peter Brock and has regaled me with many a fun tale of Brock's exploits,and Peter is held in the highest regard.
The Daytona can almost be considered a follow-on to the coupe that Kamm designed for Briggs Cunningham for LeMans, more than a decade before the Daytona,in which Carol Shelby was probably competing against. Brock,as we see, used Kamm's (Fachsenfeld's) 1930's signature truncation.:)

Interesting:
https://en.wikipedia.org/wiki/Mauro_Solar_Riser

Tell us about that geodesic dome. Diameter/frequency? Wood, metal or concrete?

Over in the VW thread I posted about Peter Brock's low-light bay window. Jay Leno interviews him while they riding around in it. He does have some interesting stories.

dome
 

It's a 30-someting foot diameter,split-level,sunken living room,with a smaller dome glomed on,concrete foundation,all,over a below-ground concrete,multi-car garage.It has some south-facing passive-solar glazing, looking onto a pool- deck.Bob did a seven-well, ground-sourced heat pump (he retired from an heating and air conditioning career after a couple hitches in the USAF).
The home is all-wood construction,blown-cellulose insulation,composite roof,with bubble skylights.Acreage with shop/hangar,and landing strip,and flies ultralights from the property,hence Larry's shared aviation interest.Bob also has a reputation as a great ultralite 'builder.'