Ioniq 6 cd of .21!
 

https://www.carscoops.com/2022/06/th...1920s-and-30s/

Taking inspiration from the old days for stream lining and achieves a cd of just 0.21!

Features

Those boxy rear-view cameras seem mismatched.

They didn't discuss the 'separation traps', did they?

Reading the general public's comments in that video link, about 2/3rds think it's ugly and don't get "it" (aerodynamics), and 1/3rd like it and understand it or say it will probably grow on them.

It's a start folks. :cool:

I'll spend the rest of the day catching up on the Pelican Parts thread. :thumbup:

http://forums.pelicanparts.com/uploa...1656530952.JPG
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Same fender line. It's a porky looking thing compared to the concept:
This is it! Hyundai IONIQ 6 - What happened?

Yeah I wish they’d go into detail about what a separation trap is

I'm just delighted the stupid oversized faux grill fad isn't being perpetuated in this design.

Impressive CD, but I still cant help but see this from the front:


https://ecomodder.com/forum/attachme...1&d=1656881317

https://sasatimes.com/wp-content/upl...s-Benz-EQE.jpg

Now that you mention it, I'm seeing things too. :D

https://www.thecurrent.org/feature/2...reak-harmonica
https://img.apmcdn.org/e2db34e0e0314...521-dylan6.jpg

...

IONIQ-6
 

Looks very familiar.
'Free-range kilowatt-hours'

additional views
 

Nice retrospective. Although, the 1986 Olds Aerotech is a stretch.

I'm putting the 2022 Tatra 77 Homage concept in the Interesting Aerodynamic Cars thread.

https://www.motorbiscuit.com/wp-cont...p?w=1200&h=801

Tatra 77 Homage
 

' would have been nice for us if it was actually a self-powered, producible concept, that they'd road tested and run the numbers on.
The more comfortable consumers become with these uninterrupted 'single-bow' rooflines, the better.

IONIQ-6 Road Test
 

The latest issue of MOTOR TREND includes a brief road test of the car in South Korea.
Length-191.1" ( 4853.94mm )
Width- 74.0" ( 1879.6mm )
Height- 58.0" ( 1496.06mm )
Cd 0.21 ( compared to the Cd 0.29 IONIQ-5 )
Estimated Af 26.03- sq-ft ( 2.41826 meters-sq )
Est. CdA 5.4663-sq-ft ( 0.50783- meters-sq ) [ @ 86% of gross area )
The author believes that the aero will add 15-20% range, compared to the IONIQ-5.
@ 77.4 kWh, that's 2.29639-gallons-e
EPA COMBINED 130.639- mpg
Range about 273-miles @ 100% SOC.
I estimated a L/sq-rt of Af @ 3.121349
At this est. fineness-ratio, the Hyundai's body is more efficient than:
2006 Chevy Cobalt ECOTEC LSR
2020 LUCID AIR work-in-progress
2021 Tesla Model S Plaid
1989 Renault Megane concept
2007 Ford Fusion 999 LSR
1935 FKFS 5-PC K-form model ( lange-heck )
2014/2017 SPIRIT of Ecomodder.com ( w/ unibody/Viper windshield, grilleblock/ SCCA racing mirrors/ restored belly pan )
The 1984 Citroen ECO 2000 concept data remains unavailable to us.

Thanks for the cD figures. I just came across a test of this car and hung on to find out the cD.
After a moment or two of looking at the design from different angles, I just said to myself that this one was just another Nissan Leaf type design - stubby and no more aero than what we had nearly 30 years ago.
Thanks for proving me wrong ! .21 is pretty decent !

I notice they had to stretch it to fit the roofline of the Benz, which is closer to the template.

This is yet another car that puzzles me. It has too "fast" of a drop in the rear glass, yet gets a .21 cD.
I would have thrown up my hands and given up on the idea of templates and boat-tails, except for the fact that the Mercedes Concept IAA dropped it's cD lowest with the addition of a short tail section.

So, Aerohead - if this design had just left off that shelf spoiler, and instead followed the template curve, would the cD have been lower ?

IONIQ @ 'template'= 'lower'?
 

I believe so.
The Ioniq 6 ( pseudo-Jaray ), @ a fineness ratio of approx. 3.121349, and Cd 0.21 IS more efficient than some other Cd 0.21 cars.
However, if you consider the M-B Bionic Boxfish ( kammback ), which is 12.7% more 'bluff' yet Cd 0.19, or the Coventry University-modified Audi A2 ( kammback ) , which is 16.9% more bluff, and Cd 0.204, then the Ioniq doesn't shine so bright.
If you agree that the Ioniq 6 shares DNA with the 1968 PORSCHE 911 ( pseudo-Jaray / pseudo- Lange-car ), and the 911 had serious lift and drag issues, and the proper solution was a 'kammback', then it's not a reach of the imagination that a 'kammback' on the Hyundai would have improved things.
Since 1974, I've seen no evidence that a 'shape' exists, which can out-perform the 1930s 'kammback.'

'separation traps'
 

While a video at carscoops purports to explain all the aero tricks used on the Ioniq-6, it failed to do so.:(
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PS:
As to the shape that's never been seen before, I'd recommend a look at the 2011, Mercedes-Benz F125 concept's roofline.

'Hyundai Ioniq 6 Aero Secrets'
 

I GOOGLED 'Ioniq 6 in wind tunnel, and this video came up.
This is all in Korean, with English sub-titles, by the CFD and wind tunnel folks who did the grunt work on the car.
All the tricks are discussed, however, no 'quanta' are provided.
https://insideevs.com/news/621207/hy...ic-efficiency/

They're got themselves a really photogenic wind tunnel. :)

'photogenic'
 

Yeah, she's a real sweetie!
Anechoic too!
Which could lead one to believe that the now-infamous 'separation trap' was as much to do with 'noise' as it was drag; since it's also something regulated by the EPA.;)

Ioniq 6 Blueprint
 

For anyone interested in the parametrics, blueprints are available.
https://www.the-blueprints.com/vecto...undai_ioniq_6/

some observations from Ioniq 6 blueprint
 

Al printed off a blueprint of the 6 for me, and I photo-enlarged it up to my contour scale and threw it on the light table.
* Without the upper and lower rear spoilers, the roofline is a very close match to Wolf Hucho's 1978, basic, 1/2-body roofline, on display in the Deutsches Museum in Munich. It goes as steep as 29-degrees slope, and produces Cd 0.15.
* If you create a vertical line, originating at the rear face of the 6's rear tires, and project it upwards, it will intersect the backlight where there's a probability for flow separation.
* The upper spoiler's tearing edge lofts the separation point upwards, with a tangent angle relaxed to 15.5-degrees off horizontal. This re-accelerates the flow, mitigates the adverse pressure gradient, allows for re-attachment, and some pressure recovery before the flow reaches the wake. This tearing edge 'contour' is almost a dead match to Wolfgang Klemperer's 1922, basic, 1/2-body, tested at the Zeppelin Werke.
* From the Hyundai wind tunnel smoke-flow imaging, the lower spoiler is almost completely embedded within the turbulence behind the upper spoiler, catching only a little edge flow.
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If you're tracking parametrics, you'll notice that the Ioniq 6's aggregate dimensions are very similar to those of other cars of similar Cd.

A reasonable 3D model is available at https://3dmodels.org/3d-models/hyundai-ioniq-6-2024/

What I really wish my I6 came with was an interior indicator for the front flaps. I think I know when they open and close but not 100%.

model 'size'
 

Not sure if the file is large enough for CFD. And I didn't recognize any software formats mentioned, which have been associated with CFD.
Router Remmerie, of AirShaper has posted that, a model, scanning, surface meshing, and CFD, is going to cost $4,000 ( US ) for a single 'solution.'
At $ 193.00 for the IONIQ's data cloud, I'm suspicious of its efficacy.
I'm meeting with one of the lab managers with the College of Engineering at the University of North Texas' Mechanical Engineering Department, and hope to have some actionable information about CFD to share soon.