Turbine style rims
 

I was reading the thread that Dogman started about side skirts and one of the comments got me thinking. Side skirts are for keeping turbulent air from under the car right? Even though some gets under there anyhow, less must be better.

These are the rims I had on my old truck. I still have them because I think they look neat and they don't cast them anymore. The "blades" are perpendicular to the truck, but what if the blades were tipped to draw air out from under a vehicle?

A balance would have to be found so air being drawn out isn't at such a high velocity as to cause more turbulence along the sides, but would it be a help or a hindrance?

I could see where if you had a large airdam and side dams (?) extending down from the rocker panels, it would make for too low a pressure underneath, causing down force and that would be bad. But with a standard suspension and minimal damming, would it help smooth out the airflow underneath?

I can't see where tipping the blades the other direction so air moved inward would be good either. It would cause lift and maybe dangerous handling. Maybe if the amount of down force could be counter acted somewhat. Would it make the vehicle more "neutral" (less down force) and improve FE? Or help accelerate airflow under the vehicle? Depending on degree of tip or if the incoming air could be directed of course.

Or....... I've finally gone off my rocker, letting my brain have free reign until this broken foot heals.

Internet picture. Not my old truck.

I wonder if they are lighter than the steel rims on my new truck.

Interesting idea, but pumping air is not efficient, no matter how you slice it.

I ran a set of those, minus center cap on both my Rangers, with a 235/60 tire on my 95 and a 225/60 on the 88... I don’t think they help aero but they do look damn nice lol...

Hmmm interesting idea

The wheel spokes are occluded by the brakes. More air is moved by the rotating tire that can fit through an opening in the middle.

If you look at trucks in the rain on the freeway, you see that there is a rolling mass of air moving outward and forward already.

That said, https://www.rimstyle.com/pages/directional.html
https://www.rimstyle.com/images/directional.png

I had to dig up how they were supposed to work. These came along in the 80s, a turbofan style wheel. Audi was banned from a racing series or two for running these at all four wheels. I chose a smoky picture of Ken Block's Gymkhana 6 car to illustrate what they do: they pull air out of the wheel area for brake cooling, and when done all-around, can reduce lift forces under the car (that's what Audi was banned for). I don't know that this would be beneficial for mileage, but it sure makes a cool photo...the other two are vintage racing wheels made to do the same thing.

Keeping the air under the car.

An airdam allows less air underneath, pushing it aside instead.

Airflow is sideways, out from under the car.

Generally, the less you mess about with air, the less drag.

If you mess with it, do so in the way the air would rather like to go.


Too much disturbing features underneath a car

That's why you see the real efficient vehicles on here, run a smooth full underbelly pan

With a full bellypan, the airdam and side skirts are redundant. The underbody is a plenum with one moving and one stationary wall (ignoring in/out the sides). More road clearance can be helpful but it means more tires exposed and bad transient response in corners.

Thanks, I thought about that example, but I went with the first thing I could find. How about Morelli Urban Car:

http://i300.photobucket.com/albums/n...il-Morelli.jpg

The rear wheels pump air over the brakes and then into a duct to the Annular truncation, right where it would otherwise be disrupted by flow from the wheels. Helpful patent drawings. An improvement to devices for reducing drag in vehicles

So if one were to make the underbelly completely flat, including bits for the exhaust, would that provide the most benefit?

I wonder if the exhaust and other bits are wrapped with those fiberglass wraps, would that enable a full covering of the underside?