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Almost flying Automobiles

roof-mounted wing
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Is it possible to design a roof-mounted wing for a car that can be tilted, so as to create lift- though not enough to actually lift the vehicle off the road? This would reduce fuel consumption and tire wear as well as reducing emissions. The angle of tilt could be controlled electronically so that the lift generated at high speeds does not destabilize the car. It may look somewhat like a broad surfboard with a centrally mounted strut, fitted a few inches above the cars roof. The weight of the vehicle will reduce when it is in motion.
Avendra, Sep 29 2003

Obstructed field takeoff procedure http://www.av8n.com...-obstructed-takeoff
[scad mientist, Oct 04 2004]

[link]






       As I understand things, there isn't enough matter in the universe to fuel and engine that would get you even near the speed of light in order to change the mass of your vehicle...
Tiger Lily, Sep 29 2003
  

       no again. :) car spoilers work in reverse of this concept for a reason. cars moving at a speedy pace need more traction to navigate corners well (i.e., not fly off the corner and wrap around a tree).   

       A fly car would be nice, but making the car lighter would be dangerous except under controlled conditions and on stright drives.
butterhed, Sep 29 2003
  

       Good one Tiger Lily- what I meant to say was the weight will reduce.
Avendra, Sep 29 2003
  

       Ah... a small adjustment is required here. What we need is a spoiler which can quickly adjust up or down.   

       When travelling straight, the spoiler automatically adjusts to reduce the weight of the car. But as soon as you turn the steering wheel, the spoiler adjusts down and gives you more weight for cornering.   

       There are two problems however. Firstly, it would make your car a death-grap in a crosswind. Secondly, most of the cost of pushing a car is related to air-resistance, not the ground-effect work.
the_jxc, Sep 29 2003
  

       Almost yay!   

       Besides, increasing your speed, especially as you approach c, increases the mass.
bristolz, Sep 29 2003
  

       Oh but the car *will* loose weight as it travels. As the car’s liquid fuel is combusted, the oxides will leave the car in gaseous form, out the tailpipe. My car loses about 4 ounces per mile city, 3.5 ounces per mile highway.
Laughs Last, Sep 29 2003
  

       Avendra, around here, one is always watching for holes to poke doughy fingers into.   

       And you were actually correct the first time for using the term mass, however, regardless of its form, in this scenario mass is added in the form of wings, adding more of it to your vehicle won't give you less of it in the end equation.   

       Heh, [bristolz], that was presumed.
Tiger Lily, Sep 29 2003
  

       [Avendra]: If you’re going to lighten the load on the wheels to reduce drag, why no eliminate the wheels altogether?   

       Design a car that has a lifting body and flies in a small channel, suspended by the air passing underneath, in ground effect.   

       Perhaps you could have small retractable wheels for when your speed is a little low.   

       You’d have to install some type of airplane-like propulsion system. I’ve seen ‘flying’ boats that use a similar idea.
TIB, Sep 29 2003
  

       This idea was well baked in the early version Toyota MR2 I once drove. Over about 140 kmh the steering would go light and it became dramatically susceptible to cross-winds. Asolutely bloody terrifying.
Gordon Comstock, Sep 29 2003
  

       Or the early Audi TT.
FarmerJohn, Sep 29 2003
  

       // This would reduce fuel consumption and tire wear as well as reducing emissions. //   

       Nope, it would increase fuel consumption because of the drag.
RayfordSteele, Oct 02 2003
  

       One way that wings on cars could potentially reduce fuel consumption is by installing retractable wings on light, areodynamic vehicles so these cars could glide from from specially installed take-off points to lower altitude destinations.
Aristotle, Oct 02 2003
  

       No, rolling resistance is generally less than induced drag (the drag generated in the process of producing lift), even while wing is in ground effect.   

       I've read that in an airplane when there is a long smooth runway, but some obstruction that must be flown over past the end of the runwway, it is better to keeps the wheels firmly planted on the runway during the entire takoff run because the airplane can accelerate faster if it doesn't have the induced drag creating lift.   

       If it is a rough runway (a grass runway for example), It is better to get a couple feet into the air as soon as possible and then ride in ground effect while building up more speed.   

       I would guess that most roads are more like the smooth runway case, so it's better not to have wings.
scad mientist, Oct 02 2003
  

       Spoilers HAVE been made that adjust to your driving conditions to give the car moew downforce while driving, I beleive it was McClarin.
Toyman, Nov 19 2003
  

       Actually, it's when you have a -short- smooth runway that you want to keep the wheels planted on the ground as long as possible. You actually get off the ground a little later, but you can accelerate to "Vy", or best angle of climb, sooner. Normally, you accelerate to "Vx", or best rate of climb. (Best rate gets you to altitude in less time. Best angle gets you there in less distance.)   

       Of course, even more fun can be had on a long smooth runway by flying just above the surface in ground effect until maneuvering speed and pulling back hard. Can we say "going up!"?
Freefall, Jun 23 2004
  

       [FreeFall] Are you sure you don't have Vx and Vy mixed up? In all the references I've seen, Vx is best angle of climb.   

       Yes, "long" probably wasn't quite the right word. I think what I was meaning was not too short. See link and footnote 1. If your runway is too short you can't keep your wheels on the ground until Vx or you'll run off the end, but then again maybe you shouldn't be using that runway at all in that case...
scad mientist, Jun 23 2004
  

       My mistake. Yes, I had Vx and Vy reversed. Thanks for the correction. I've never had a problem remembering what the actual speeds were, but I have a habit of getting the names mixed up.
Freefall, Jun 23 2004
  

       Just don't confuse anything else for Vne.
bristolz, Jun 23 2004
  

       [freefall], I always taught my flight students that Vx and Vy could be remembered by remembering that an "X" had more angles than a "Y". Hence, Vx is best angle.
zigness, Jun 23 2004
  

       About the idea... it won't work... it disregards induced drag (among other things).
zigness, Jun 23 2004
  

       This last bit of discussion explains what I used to observe watching Tornados take off. They'd start at the beginning of the runway with the wings swept back and bring them forward just before lifting off.
Gordon Comstock, Jun 24 2004
  

       Bullshit, James Bond did it over that water fall when Jaws was chasing him in the speedboat. En stuff. Then Jaws smoggled that chick on the space station. You just have to ditch the car-part and become a beutiful "hanglider", chuckles to himself and says I love this place. + for forgeting subliminal influence. um hum , shure.
czynachos, Jul 13 2004
  

       Hmm.. Smells like a Hovercraft to me... Instead of wings why not put a skirt and blower underneath?   

       The lift fan will provide thrust and a substantial portion of the vehicle weight could be supported by the resulting air column.   

       In this case you may not even need the skirt as your intent is for the car to still be propelled and controlled by the wheels.
Shapharian, Oct 09 2007
  
      
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