h a l f b a k e r yVeni, vedi, fish velocipede
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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.
Obstructed field takeoff procedure
http://www.av8n.com...-obstructed-takeoff
[scad mientist, Oct 04 2004]
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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... |
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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). |
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A fly car would be nice, but making the car lighter would be dangerous except under controlled conditions and on stright drives. |
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Good one Tiger Lily- what I meant to say was the weight will reduce. |
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Ah... a small adjustment is required here. What we need is a spoiler which can quickly adjust up or down. |
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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. |
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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. |
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Besides, increasing your speed, especially as you approach c, increases the mass. |
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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. |
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Avendra, around here, one is always watching for
holes to
poke doughy fingers into. |
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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. |
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Heh, [bristolz], that was presumed. |
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[Avendra]:
If you’re going to lighten the load on the wheels to reduce drag, why no eliminate the wheels altogether? |
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Design a car that has a lifting body and flies in a small channel, suspended by the air passing underneath, in ground effect. |
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Perhaps you could have small retractable wheels for when your speed is a little low. |
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You’d have to install some type of airplane-like propulsion system. I’ve seen ‘flying’ boats that use a similar idea. |
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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. |
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// This would reduce fuel consumption and tire wear as well as reducing emissions. // |
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Nope, it would increase fuel consumption because of the drag. |
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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. |
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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. |
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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. |
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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. |
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I would guess that most roads are more like the smooth runway case, so it's better not to have wings. |
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Spoilers HAVE been made that adjust to your driving conditions to give the car moew downforce while driving, I beleive it was McClarin. |
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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.) |
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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!"? |
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[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. |
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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... |
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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. |
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Just don't confuse anything else for Vne. |
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[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. |
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About the idea... it won't work... it disregards induced drag (among other things). |
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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. |
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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. |
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Hmm.. Smells like a Hovercraft to me... Instead of wings why not put a skirt and blower underneath? |
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The lift fan will provide thrust and a substantial portion of the vehicle weight could be supported by the resulting air column. |
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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. |
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