Can we increase the wing area vertically?

[The_Thinker]

hmmm... i was just wondering, if we increased the area of a wing and sacrifice drag, we should get more lift right? and if we got more lift, should we not be fly with a low velocity?

And I am not talking like gliders and increasing the wingspan, I am thinking about increasing their area vertically... is this possible??

Im not an aeronautical engineer or anything, i just thought it should be possible after going through how a wing works... so if you can help me out, it would be good...

 

[ank_gl]

what do you mean by increasing the area vertically? do u mean increasing the thickness?

 

[FredGarvin]

It's not a simple tradeoff like you are thinking. The result of lift is drag. Not only parasitic, but induced drag. Also you increase the weight.

I have no idea what you mean about increasing the area vertically.

 

[Langbein]

It's true it will produce to much drag, but there have been som thick wing designs. Junker had a model once with passengers sitting inside the thick wing. It lookes like it had a Boeing 747 style Cocpit as well. (The jumbo airliner of the thirties)

http://www.geocities.com/hjunkers/ju_g38_a1.htm

Some more modern design that has not yet been a success:

http://en.wikipedia.org/wiki/Boeing_X-48

 

[Danger]

Well, I guess that it depends upon what you mean by increasing it vertically. There are devices called Whitcomb winglets that look like vertical stabilizers on the tips of the wings. I have no idea of how they work from an aeronautical engineering standpoint, but I'm sure that Fred, Russ, Rainman Aero and a few others can tune you in on that. The essence, however, is that they 'trick' the wings into acting as if they're much longer than they really are. My best semi-educated guess would be that it has something to do with harnessing wingtip vortices, but I really don't know.

 

[ank_gl]

winglets produces the infinite wing span effect

 

[Langbein]

No and yes .. The "only" effect of a winglet is to reduse drag due to wing tip wotex'es. Possibly it has som other effect as well as a slightely increased lift and improved stability.


http://www.b737.org.uk/winglets.htm

 

[FredGarvin]

That is, in essence, what an infinite wing span is. It does not suffer from drag induced at the tips. Winglets do not produce that effect, but try to simulate it. We will never fly a wing that exactly reproduces an infinite wing's performance.

I have read a couple of papers in which they claimed that there was also a slight propulsive force created at the winglets due to their aerodynamics.

 

[The_Thinker]

Hmmm... what I meant was since that since the lift depended on the angle of attack and area of the wing, if we were to increase the area of the wing linearly as in not the wingspan, but the actual breadth of the wing. These probably aren't the best words, what i mean is as illustrated in the diagram below...

So... if we can increase the breadth of the wing would we be able to increase the lift, sacrificing the drag? this is what i wanted to know...

 

[LurkingEyes]

You mean making the wings Deeper instead of Longer or Taller? Sort of like the space shuttle or the XB-70?

 

[The_Thinker]

exactly... XB70?

 

[LurkingEyes]

http://en.wikipedia.org/wiki/XB-70_Valkyrie

It used a delta-wing design, for ease in supersonic speeds, had sort of an accident.

Also, this isn't "Vertical" as you first asked, but I'm running with it.

And almost the opposite of what you're asking, the Delta Wing design I'm assuming you are thinking of was use a lot more for High-Speed (and supersonic) than low speed because it was a lot of weight. They suffer from flow separation at a higher angle of attack (probably didn't help in the Valkyrie crash), which normal wings are better at preventing. They also don't provide as much of a L/D Ratio as you'd think, as planes like the B-52 (long wings) outperform them.

More of the earlier jets used that design, but some (like the Eurofighter and the F/A-18 Hornet, F-16, etc.) still use some variant of it. Normal wing design won out in the long run though.

The wiki article sums most of it up, http://en.wikipedia.org/wiki/Delta_wing"
And http://www.aerodyn.org/Wings/delta.html"

Someone else can probably explain more in detail though.

 

[FredGarvin]

Are you referring to increasing the chord length? I'm still a bit confused, even with your diagram.

The XB-70...what a great aircraft. Absolutely awe inspiring to stand underneath it back at the engines and look forward.

 

[The_Thinker]

no actually what i meant by the whole vertical thing is that...

Why even bother with the whole combination of both the bernoulli and Newton thing and just instead use the Newton idea...

I hope this very poorly drawn diagram can represent the question I am trying to ask...

also... why even bother with the thrust what with all the drag and all? why not just provide actual thrust in an inclined direction and forget the wing thing? as provide the thrust from the bottom with an engine and incline it in the required direction?

Oh... thanks for clarifying my thoughts so far...

 

[Danger]

Now it looks as if you're talking about a 'scissor-wing' (oblique) like the AD-1. Is this what you're getting at?
http://www.nasa.gov/centers/dryden/history/pastprojects/AD1/index.html"

 

[ank_gl]

also... why even bother with the thrust what with all the drag and all? why not just provide actual thrust in an inclined direction and forget the wing thing? as provide the thrust from the bottom with an engine and incline it in the required direction?

giving thrust sounds pretty much easy. but as far as i understand a wing also gives you the required stability. consider this idiotic example, what if the thruster blows up?, we all die, haha. but add the wings into the story, you can easily glide to safety.
also wing can give much more lift at lower speeds of engines then a thruster would do. cost is also a factor, you can't put big thrusters on every aircraft

 

[russ_watters]

Gah, you're really killing me, Thinker. Look http://hyperphysics.phy-astr.gsu.edu/hbase/fluids/airfoil.html" for airfoil terminology.

The vertical dimension is thickness.
The front-to-back dimension chord.
The side-to-side dimension is span.

It sounds to me like you want to increase the chord. Is that correct?

If it is the chord you are looking to increase, the primary drawback of that is what the guys were discussing above: with a long chord, short span (aka, low aspect ratio) wing, the wingtip vortices are proportionally larger, increasing drag and decreasing lift.

 

[russ_watters]

also... why even bother with the thrust what with all the drag and all? why not just provide actual thrust in an inclined direction and forget the wing thing? as provide the thrust from the bottom with an engine and incline it in the required direction?

You mean like with a helicopter? The main reason is efficiency: the type of thrust that is most efficient for lifting is high volume, low velocity. The type that is most efficient for high speed is high velocity, low volume. You'll note that most airplanes do not have thrust to weight ratios greater than 1.

 

[LurkingEyes]

That Thing would scare the crap out of me.

also... why even bother with the thrust what with all the drag and all? why not just provide actual thrust in an inclined direction and forget the wing thing? as provide the thrust from the bottom with an engine and incline it in the required direction?

Because that takes a Lot of fuel. With wings you let nature do Some of the work by gliding, and you glide as long as you're moving forward (albeit a powered glide). With that, you basically have a rocket, and we don't have motors efficient enough to stay on for that long of time. You also get that there are no control surfaces, so your motors have to do that as well. Plus unless you have yet another engine that is reserved for only forward thrust, with an engine at a 45 or 60 degree angle to also provide lift, you'll never get the full forward-velocity that you Could get.I also didn't see there was a second page.

 

[The_Thinker]

yeah I did mean the "chord"... and well...

You mean like with a helicopter?

hmmm... well actually I meant like the X-22..
here:

http://www.centennialofflight.gov/essay/Evolution_of_Technology/VSTOL_aircraft/Tech30.htm"

Regarding the bigger chord:
RIght... so its less efficient... that's okay... but one can produce good lift at low velocities right... besides, after reaching a certain height, the wing can be folded or lowered or rised or something, to reduce the drag right?

Regarding the vertical thrust:
Also... Let me get this straight... its more efficient to induce drag to a plane to make it take off and less efficient to supply the thrust on your own? Ah... could you show we the equations involved?

And... well... about the safety thing, that's why we have parachutes right?

 

[ank_gl]

Also... Let me get this straight... its more efficient to induce drag to a plane to make it take off and less efficient to supply the thrust on your own? Ah... could you show we the equations involved?

And... well... about the safety thing, that's why we have parachutes right?

both cases for take off
let the mass be m
CASE 1- wings
T thrust , D drag
acceleration = (T-D)/m
velocity = (2*a*s)^0.5
lift =(density*vel^2*Cl)/2
here lift = m*g
CASE 2- thrusters
let 'em put the max power, ie. let them be vertical at the start(VTOL)
therefore T=m*g

now calculate taking appropriate values(just basic physics equations)
others can really help actually

oh safety, that's why roads are. why fly, when you can safely walk home!

 

[russ_watters]

RIght... so its less efficient... that's okay... but one can produce good lift at low velocities right... besides, after reaching a certain height, the wing can be folded or lowered or rised or something, to reduce the drag right?

Well, you can certainly reconfigure a wing in flight to optomize efficiency (see: F-14), but the machinery adds weight to the plane. It's a tradeoff.

Regarding the vertical thrust:
Also... Let me get this straight... its more efficient to induce drag to a plane to make it take off and less efficient to supply the thrust on your own? Ah... could you show we the equations involved?

No need for equations (that could get very complicated), just look at the thrust-to-weight ratios of a few airplanes: http://www.boeing.com/commercial/747family/pf/pf_400_prod.html

The 747's engines produce 63,300 lb of thrust each (x4) and the gross takeoff weight is 875,000 lb. That's a thrust-to-weight ratio of 0.29. So if you wanted a vertical takeoff 747 with pivoting engines, you'd need 14 engines.

Remember also that high speed performance is more important than takeoff performance, so planes are designed with that in mind. And you'll note that propulsion from helicopters and jet engines involves fundamentally different populsion devices - you wouldn't for example, strap two jet engines to the side of a helicopter to replace the rotor.

Hmmm... actually, the equations involved aren't too bad. You can derive it from the fan law ( http://www.efisystemsgroup.com/fanlaws.htm ). The issue is that to drive a plane fast you have to make the engine exhaust move fast and making the exhaust move fast requires a higher pressure than making it move slow, which in turn requires more engine power.

edit: ehh, it isn't quite that bad. Jet engines get compression from the incoming air's velocity and actually are more efficient at high speed. The fact that they need air to be in motion to function efficiently is probably a bigger issue than the pressure-velocity-horsepower relationship.

 

[Danger]

about the safety thing, that's why we have parachutes right?

So it conks out, you pull the panic-rack and float gently to Earth. Suppose you're over New York City at the time. How many people is that vehicle going to kill when it lands without you?

 

[FredGarvin]

Jet engines get compression from the incoming air's velocity and actually are more efficient at high speed. The fact that they need air to be in motion to function efficiently is probably a bigger issue than the pressure-velocity-horsepower relationship.

While ram effect is a nice thing usually, the greater gains are simply from being at altitude. Engine specifications are derived from test data taken in a cell at close to sea level and static conditions.

 

[The_Thinker]

ah yes... but who needs high speed? I am talking about cars... SO if we had a low velocity and a big chord length one can get a vehicle to take off and have a low velocity but one can have flight...

Anyway...
About safety, well accidents happen everyday... and besides, I am thinking about a High Capacity battery powered engine... and battery engines are less likely to blow up, right... we would just need the right precautionary methods... and it should work right?

The point is, if we had a plane, then the shortest distance between any two points is always going to be a straight line unlike a car in which the shortest distance, always has the worst roads...

 

[russ_watters]

Whether the speed is low or high, a high aspect ratio wing is still more efficient than a low aspect ratio wing.

 

[Langbein]

If you mean by "efficeincy" the content that this word nomally wil have the realtionship between the lift and the drag, it is true that a thick wing allways will produce a lot of drag, so it not be "effecient" in that way.

If the word "efficiency" should mean something else, something to "how to produce as much lift as possible with a wing that has a small area", then the situation is changed.

Wing for bigger aircrafts is allways built with a leading edge slat and a trailing edge flap, to increas "the aerodynamic thicness" of the wing while flying at low speeds.

While doing the landing the increased drag is a wanted effect to reduce the forward speed of the aircraft.

It is true that if you should make as much as possible lift on a wing with as small as possible area, it should make be made aerodynamically "thick". On the other hand this would require the consume of a lot of fuel to keep it flying.

 

[Langbein]

http://en.wikipedia.org/wiki/Slats

Figure 2 on the next link shows a bit of this prinsiple:

http://www.aerodyn.org/HighLift/high_lift.html

In such a design the "thick wing" can be made with some leakage from the underside to the overside to control the airtream will not stall out and get turbulent separeted on the upper wing surphase. Such a wing design will produce a lot of lift and drag.

And one more:
http://adg.stanford.edu/aa241/highlift/highliftintro.html

 

[AlephZero]

The point is, if we had a plane, then the shortest distance between any two points is always going to be a straight line

No, it's a great circle, not a straight line

 

[Langbein]

.., I am thinking about a High Capacity battery powered engine... and battery engines are less likely to blow up, right... we would just need the right precautionary methods... and it should work right?

Technically it could be possible to build a low flying airplane with courved aerydynamically "thick" wings. Then the increased lift from the "thick wing design" will add up with the ground effect, producing even more lift.

On the other hand this will require a very strong truster. (Fan or propeller.)

I guess that the only intallation that will give power enough for some time will be a jet turbine engine. (Like a small fan jet or a small turbo propeller engine.)

Relatively smaller propeller turbo engines can be bought as standard aircraft parts, but they are still quite expensive.

I believe such an aircraft would have poor aerodynamic stability due to its low speed.