Making the Ioniq slippier

[aerohead]

Originally Posted by freebeard

Fails on ingress/egress.

Why would you say something like that?

[freebeard]

Why would you say something lake that?

Because it's a forum for discussion? Lake it or not.

[aerohead]

You understand that we're talking about a 'CUER' that's 1450mm tall?
Four-doors?

[freebeard]

This architecture would come close to satisfying your design specification.

inhabitat.com/cuer-unveils-streamlined-sun-powered-car-for-the-2013-world-solar-challenge/


Where would you put the doors?

[aerohead]

https://ecomodder.com/forum/showthre...rt-c-9287.html

Originally Posted by freebeard

inhabitat.com/cuer-unveils-streamlined-sun-powered-car-for-the-2013-world-solar-challenge/


Where would you put the doors?

As above, in #43 (permalink )
the 'architecture' would be 1450mm ( 56.9" ) tall and 5,902.95mm long.
The four doors would be much like in the AST 'template.' Just add rear suicide doors behind the front doors shown.
Conventional upright seating.
'Shape' is the issue, not 'scale.'
Verisimilitude gives us any scale we choose for a given 'shape.'
And IONIQ is already 'template,' so it's just a matter of elongation, after all the OEM details are fine-tuned.
CUER measured Cd 0.11 in the Airbus wind tunnel. It can be degraded a bit and still satisfy the 60 @ 80 metric.

[freebeard]

'Shape' is the issue, not 'scale.'

The Ioniq is quasi-superlliptical in cross section, not ovoid. I don't see the cut-shut-and-weld that would get you there.

A full boat tail would double the overall length.

[Phase]

Originally Posted by aerohead

I looked at it and vote thumbs-down on the rear spoiler.
1) The IONIQ is already on the 'template' contour at its upper separation point.
2) Directing the flow up and over a rear spoiler would only re-accelerate the local flow, destroying the only thing which could provide pressure recovery, a higher base pressure, and lower overall drag.
3) I like the front wheel arch gap-fillers. That's a GO!
4) I like the rear wheel skirts. That's a GO!
5) Any additional paneling you can get away with underneath.
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6) As the Cd comes down you'll need less and less cooling, as with Mercedes' new EQXX.
7) There may be a tiny amount of fruit with more 'Tesla-esque' side mirrors, on very-narrow stalks, at least 80mm away from the body.
8) 'Janky' coroplast wheel covers zip-tied to alloy wheels, or ventilated Dzus-fastened MOONs on steel wheels.
9) I've never seen an IONIQ at rest. If you can tell us where the rear diffuser begins underneath the car, there might be a recommendation for its upsweep angle.
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After all existing OEM features are addressed, you need to consider basjoos' comment about a receiver-hitch-mounted tail.
10) The IONIQ is missing 84-inches of body length.
11) You only have 43% aft-body as it is.
12) Your Length-to-Height ratio is only 3.082:1.
13) In order to approach your target 60-mpg @ 80-mph, you'd actually need a fully-gap-sealed, fully-boat-tailed, tadpole trailer, like BamZipPow's.
14) Any remarkable drag reduction is going to come from elongation. There's no way around it.

https://www.trdparts.jp/english/product/prius/aero.html

check out what japans engineers did for the prius for aero add ons. i know its prius, but the overall car shapes are similar. notice the rear spoiler they did extends out and down past the body, the slightly flips up? i was thinking of doing something similar for my rear, or at least extend the upper and under body spoilers and have them going slightly inward like a mini box cavity

toyota also made a front lip spoiler and side skirts, but most people on this forum say those dont do much for modern cars, so no idea why toyota did it.

i for sure need to get a smooth under body, the rear exhaust area looks the trickiest for covering though

[aerohead]

Originally Posted by freebeard

The Ioniq is quasi-superlliptical in cross section, not ovoid. I don't see the cut-shut-and-weld that would get you there.

A full boat tail would double the overall length.

I've explained many times about cross-sectional area, and how it can be morphed back-and-forth, just like Jaray did, and just like every ASHRAE HVAC design engineer does, going from round-to-square-to-oval.................. it doesn't matter as long as the overall sectional area does not vary any more than the original semicircular section of a streamline half-body, from station to station.
On the IONIQ, the process would be purely additive. Nothing would ever be removed from the existing body, only added.
A full boat tail would add 84-inches.
Hyundai 'removed' it in the IONIQ specification. We'd just be restoring it. As Lay's Model# 22. As Carl Breer's DeSoto Airflow aero mule ( long-tail ) As Kamm/Fachsenfeld's ( long-tail ) research models. As Buchheim et al. VW Flow-Body (long-tail ). As Mercedes-Benz C-111 III ( long-tail )
As NASA shoebox ( long-tail ). As Porsche's 908 ( long-tail ). As GM's EV1 LSR ( long-tail ). As GM's Aero 2002 ( long-tail ). As Robert Cumberford's Cd 0.16 ( long-tail. As GM's Oldsmobile AEROTECH ( long-tail ).
Phase may elect to lower his mpg expectations.
I'm indifferent as to the outcome.
But if 60-mpg @ 80-mph is the target, the aft-body of the IONIQ 'MUST' look something like CUER. None of the other vehicles which share a Cd like this are as efficient in their use of materials.
If the length is an issue, then you just ( Kamm/ Fachsenfeld ) truncate it, at whatever length you desire, and live with the drag increase.

[Phase]

Originally Posted by aerohead

I've explained many times about cross-sectional area, and how it can be morphed back-and-forth, just like Jaray did, and just like every ASHRAE HVAC design engineer does, going from round-to-square-to-oval.................. it doesn't matter as long as the overall sectional area does not vary any more than the original semicircular section of a streamline half-body, from station to station.
On the IONIQ, the process would be purely additive. Nothing would ever be removed from the existing body, only added.
A full boat tail would add 84-inches.
Hyundai 'removed' it in the IONIQ specification. We'd just be restoring it. As Lay's Model# 22. As Carl Breer's DeSoto Airflow aero mule ( long-tail ) As Kamm/Fachsenfeld's ( long-tail ) research models. As Buchheim et al. VW Flow-Body (long-tail ). As Mercedes-Benz C-111 III ( long-tail )
As NASA shoebox ( long-tail ). As Porsche's 908 ( long-tail ). As GM's EV1 LSR ( long-tail ). As GM's Aero 2002 ( long-tail ). As Robert Cumberford's Cd 0.16 ( long-tail. As GM's Oldsmobile AEROTECH ( long-tail ).
Phase may elect to lower his mpg expectations.
I'm indifferent as to the outcome.
But if 60-mpg @ 80-mph is the target, the aft-body of the IONIQ 'MUST' look something like CUER. None of the other vehicles which share a Cd like this are as efficient in their use of materials.
If the length is an issue, then you just ( Kamm/ Fachsenfeld ) truncate it, at whatever length you desire, and live with the drag increase.

the 60mpg at 80 is just a dream goal. even if its 57-58mpg at that speed, i wouldn't complain too much. I'm just trying to make my car more aerodynamic without making it ugly as junk.

[aerohead]

No spoiler is capable of the drag reduction you're entertaining. Only box-cavities and boat-tails can do it.
Remember, your design specification is 60mpg @ 80-mph. And Cd 0.12, half that of Prius, Ioniq.
If it was that easy, they'd already be doing it, and you'd have your 60 / 80 ratio.
The car must be reduced to surface friction drag and wheel drag.
Surface friction we can't do anything about, but wheel drag can be cut by 70% according to Goro Tamai of MIT.