Making the Ioniq slippier

[Phase]

Originally Posted by aerohead

I'd direct your attention towards Volkswagen's 'solution' to wheel drag.
In the 'archives' there's an underbody image you should see.
https://www.volkswagen-newsroom.com/en/xl1-3588

What am I looking for exactly? I saw the extremely smooth underbody. Looks like a full EV bottom but it’s a hybrid. And then obviously they use wheel spats like I’m planning on

[freebeard]

All I saw was a pop-up demanding something about cookies.

There was a time when the Holy Template would have been the example, but here we are post-Julian Edgar.

The theory behind blisters and fillets suggests the spats should be ahead and behind the wheel and [x?] times the tire width.

[Piotrsko]

Irv Culver was a disciple of 1.5 times the height equals the horizontal spacing distance for maximum drag reduction. I couldn't argue with him, gave me headaches keeping up with his grasp of the math involved

[aerohead]

Originally Posted by Phase

What am I looking for exactly? I saw the extremely smooth underbody. Looks like a full EV bottom but it’s a hybrid. And then obviously they use wheel spats like I’m planning on

1) I think we're having a nomenclature challenge.
2) A 'spat' is an over-the-front wheel fairing, which almost entirely encloses the wheel, and turns with them. ( The 1983 Ford Probe-IV had these 'spats' beneath the elastic, urethane front wheel skirts , as a non-chafing contact surface for the inside of the skirts )
3) The Volkswagen XL1 has 'fairings,' front and rear of the wheels, which eliminate the pressure spikes introduced by the 'eruption' of the wheels out of the body. They guide the air around the sides of the wheels at the front, then function as 'boat-tails' behind, to eliminate the wheel wakes. The very detailed wheel fairings on some solar racers reduce the wheel drag contribution by 70%.

[aerohead]

Originally Posted by freebeard

All I saw was a pop-up demanding something about cookies.

There was a time when the Holy Template would have been the example, but here we are post-Julian Edgar.

The theory behind blisters and fillets suggests the spats should be ahead and behind the wheel and [x?] times the tire width.

1) I think that it's a mistake to use the term 'blister' in conjunction with 'wheels.'
2) Wheels are associated with wheel covers, spats, deflectors, skirts, and fairings.
3) Fillets are used to blend a structure onto a body, killing hook-vortices, and the interference drag they'd create in the absence of the fillet.
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4) Looking either from above, or below, wheel fairings could be looked upon as a two-dimensional flow, symmetrical wing section. In this capacity, there IS an ideal thickness ratio ( length divided by width ) for low drag. As with streamline bodies of revolution, if a section is 'longer,' it will suffer increased skin friction. If it's 'shorter', it will suffer increased pressure drag. It's a drag 'bucket' phenomena. We covered this in 2007. I don't have that with me today. ( around 3.8:1, and the aft portion of it would be around 66% of overall length )

[aerohead]

Originally Posted by Piotrsko

Irv Culver was a disciple of 1.5 times the height equals the horizontal spacing distance for maximum drag reduction. I couldn't argue with him, gave me headaches keeping up with his grasp of the math involved

Goro Tamai's book ' The Leading Edge' has the minimums. I'll try and remember that for Thursday.

[Phase]

Can anyone explain why the new Mercedes EV that gets 1000km of range is 2 points lower in drag than the xl1? Heck the xl1 has a longer boat tail, is narrower, rear wheel spats, and deleted the side mirrors

The Mercedes keeps the side mirrors and doesn’t use rear wheel spats!!

[freebeard]

1) I think we're having a nomenclature challenge.

Agreed. You left out pantaloons, or pants.

What you're calling spats, I'd call a cycle fender. And some of those new OEM deflectors are nothing more than strakes, or wickerbills.

No idea on the Mercedes EV. Generative AI?

[Phase]

Any benefits of extending rear spoiler like this? Horrible mock up shape obviously. But foot long extension should help a little right?

[freebeard]

Your search term is 'Bonneville spoiler'. Here are some examples:

Starting off with Bombshell Betty


Bonneville has lots of 1953 Starliners

It has an NSRA Safety 23 sticker and holds the C/BGALT record for the East Coast Timing Association at over 200mph. This car is driven to Wilmington Ohio from Barrie Ontario, towing a utility trailer, raced at 200mph, and driven home again.

customrodder.forumactif.org/t1872-bonneville-co