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Airfoil Rims

Shape car rims like turbines for downforce
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Car wheel spokes with airfoil cross sections could be used to add a slight amount of active downforce to the rolling vehicle, increasing traction.
kevinthenerd, Jun 14 2012

Bubbling_20Turn_20Signals Unfortunately the forces developed will play havoc with this idea... [normzone, Jun 18 2012]

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       Unless you are actively controlling them, nope. It's not possible for a passive blades system to produce a non- uniform radial force.
MechE, Jun 14 2012
  

       Yes - how do these not give a force which when summed around the whole wheel, cancels itself out?
hippo, Jun 14 2012
  

       Couldn't you just duct a lateral airflow through the wheels downwards?
AbsintheWithoutLeave, Jun 14 2012
  

       Downwards you might be able to do, but would produce a lift, not a downforce. Upwards would be through the body of the car, which might be possible on some models. I still wouldn't describe that as the rims providing the down force.   

       Regardless, it's going to be minimaly effective (ducting isn't all that efficient), and far, far less effective than a spoiler in the air-stream that produces a similar drag. Rolling resistance (which this would manifest as) is the last thing you want.
MechE, Jun 14 2012
  

       But doesn't the top of the wheel go through the air, while the bottom is not moving?
Ling, Jun 14 2012
  

       Oooh, nnaaaiiiice ...
8th of 7, Jun 14 2012
  

       //But doesn't the top of the wheel go through the air, while the bottom is not moving?//   

       You might have something there, but you're still dealing with three quarters of the rotation, with the forward and backward arc fighting each other. That might allow the wheel to produce some downforce from the top arc, but still only at the expense of considerably more drag than the equivalent downforce from a static spoiler.   

       Also the skin effect over the car would tend to negate your point somewhat, since the air right against the car is moving roughly with it. Still, valid point.
MechE, Jun 14 2012
  

       //But doesn't the top of the wheel go through the air, while the bottom is not moving?//   

       Indeed. There is an item which makes use of this imbalance of lift: a boomerang. However, I somehow doubt boomerang wheels would be beneficial.
mitxela, Jun 14 2012
  

       // I somehow doubt boomerang wheels would be beneficial //   

       They would if you only ever wanted to go back to the place you started from ...
8th of 7, Jun 14 2012
  

       <mutters something about ground effect>
FlyingToaster, Jun 15 2012
  

       A bottom-heavy 'spinner' rim (like the ones on taxis that have advertisements on them) with a canard wing extending out from it might work. Some ingenious manner of aerofoil might be arranged to keep the spinner stationary and the blade angled properly at higher speeds. It might interfere with steering dynamics, however.
Alterother, Jun 15 2012
  

       But why stop there? If a wheel can be cleverly configured to create downforce, why not apply additional cleverness and configure it to apply upforce?   

       Voila! The Flying Car!
normzone, Jun 15 2012
  

       The rims would have horizontal axes as in the current art. Forcing air from the inboard side of the car to the outboard, combined with the restriction of the air rushing in to replace it (from the front, rear, and in between the tires), would produce downforce.
kevinthenerd, Jun 18 2012
  

       [+] I'm not quite sure of the technical ability of this, but I love the idea of it!
xandram, Jun 18 2012
  

       Exactly so, [kevin].   

       "The rims would have horizontal axes as in the current art. Forcing air from the inboard side of the car to the outboard, combined with the restriction of the air rushing in to replace it (from the front, rear, and in between the tires), would produce downforce."   

       Ergo, forcing air from the outboard side of the car to the inboard, combined with unrestricted replacement air from the sides and top of the car, and outside the tires, would produce upforce.   

       Of course, I'm not buying stock in the Upforce Wheel & Flying Car Company until I see a working prototype.
normzone, Jun 18 2012
  

       For most downforce / best efficiency, you want your spoiler to be doing all the work, since it's optimized to make the most downforce per drag added.   

       I imagine a car with 4 splayed-out turbine/wheels, tires bent at 45deg scrubbing/skidding madly as the rims/turbines blow four plumes of blue tire-smoke into the air.
sninctown, Jun 19 2012
  

       That sounds about right. Better use beadlocks if you plan on going around corners, too; car tries to go left, wheels keep trying to go straight, one or more tires go right and suddenly pop off, and Jezzer wins another fiver off Captain Slow.
Alterother, Jun 19 2012
  
      
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