Question about improving miles per kilowatt

[Isaac Zachary]

Originally Posted by liquidshadowfox

Any examples of this notch?

Mudflaps, but in front of the wheels. (Notch is the area between them)

[liquidshadowfox]

Does the front grille not being smooth matter at all? Or is that minimal drag that it's not worth it? So what about putting sharp edges on the sides towards the back to disconnect the air from the side of the car?

[liquidshadowfox]

Originally Posted by Isaac Zachary

Mudflaps, but in front of the wheels. (Notch is the area between them)

Shouldn't the air curtains this car have help?

[Isaac Zachary]

Originally Posted by liquidshadowfox

Does the front grille not being smooth matter at all? Or is that minimal drag that it's not worth it? So what about putting sharp edges on the sides towards the back to disconnect the air from the side of the car?

Smoothing (and blocking) the grill should help a little.

Sharp edges might help if done correctly.

Originally Posted by liquidshadowfox

Shouldn't the air curtains this car have help?

Of course! That's probably why they're there.

But at any rate, most anything you do will be only a slight improvement (or possibly an unimprovement), maybe a percent or two. The biggest fish to catch in aero is the rear end drag.

Most aerodynamic (or hydrodynamic) objects, vehicles and animals have a long tapered rear end (planes, birds, fish, submarines, etc.).

You can have a sharper taper if you have a way of keeping the air flowing along it without it breaking away. This can be done with vortex generators (or golf ball holes, same thing only inverse.)

[freebeard]

Originally Posted by liquidshadowfox

Any examples of this notch?

Yes. I see it every once in a while, like a phantom ship. I've even saved it but my albums are a mess.

I think it was cowmeat's, but I'm likely mistaken. It's a brown Civic with a conveyor belt air dam. the notch is maybe a foot by three inches.

[Gasoline Fumes]

Originally Posted by freebeard

brown Civic with a conveyor belt air dam.

That sounds familiar!

[freebeard]

That would be the one. Bigger than I remember.

How did it work?

[aerohead]

Originally Posted by liquidshadowfox

Does the front grille not being smooth matter at all? Or is that minimal drag that it's not worth it? So what about putting sharp edges on the sides towards the back to disconnect the air from the side of the car?

* The leading edge radii are adequate enough to guarantee attached flow around the perimeter of the nose. A stagnation bubble forms, and flow diverts around it, quite a bit ahead, as if a 'phantom' nose exists. You'll see this phenomena in virtually all smoke-flow wind tunnel images. So the grille area is kind of a dead-end, drag reduction wise.
* I'd be surprised if you didn't already have separation edges designed into the rear of the car already. The Hyundai and KIA stablemates have them.

[aerohead]

Originally Posted by liquidshadowfox

Shouldn't the air curtains this car have help?

Your air curtains are already dropping the GV60's drag, from around Cd 0.30, to Cd 0.29. Their already CFD and wind tunnel optimized, so nothing more to do there, except an 'invisible' wheel cover for those wheels you like. They're killing some of your range.

[aerohead]

Turns out that the LUCID AIR has the same R-R challenge as the Genesis.
The 'performance' tires are ' range-sapping,' and the only way the Lucid can achieve it's best mileage is to, lose the 21-inch 'performance' wheels & tires, and install the 19-inch aero wheels and LRR All-Season Pirelli P Zero 245/45-19 tires, all around. The wheels have been camouflaged with black paint to hide the fact that they're a low-porosity design, to reduce ventilation drag.
When Hyundai went to Bonneville to set a land speed record with the IONIQ hybrid, they deleted the air curtains, and installed MOON racing covers, with zero-ventilation.
This ventilation drag actually raised the Cd of a Tesla Model 3, tested in Germany in 2018, increasing as speed was increased by 10-mph increments.
It appears that, when automobile manufacturers now use the term ' performance' it means the opposite of what it would mean in aviation.
You get less for more.