Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
lehpron
Topic Author
Posts: 6846
Joined: Tue Jul 10, 2001 3:42 am

My Proposal For Reducing Impact Of Wake Vortices

Thu Apr 06, 2006 12:20 pm

I came up with this idea maybe last week, please criticize. I have not done any CFD analysis or anything, this is fresh out of my mind and mainly done with thought experiments and MS paint. 

I will make many suppositions.  

From what I'm reading here, one of many problems with making planes large like A380 (or whatever Y3 ends up being) is their wake vortices. Here's my proposal: I called it a stepped wake wortex wing.

Take a gander at the picture below:



Both wing sections are supposed to have the same half-span, reference area and aspect ratio with respect to each other. The first wing piece is supposed to represent a generic slender wing with a raked wingtip device.

The spanwise flow leads to the tip swirls (vortices), that is, the entire wing "pushes" that air out over the tips. The amount is less than 20% but significant, its turbulent. I'm wondering if some of this flow were allowed to "leak" mid-span, what will happen to the remainder? I figure the resulting spanwise flow will act as if it were supporting less weight, as if it were a smaller wing.

The second wing scetion is supposed to imply that approximate half of the wake leaks over the top of the wing while the other half swirls around the wingtip. I theorize that, in effect, the vortex at the outboard wingtip has less strength.

In a real airplane application setting, instead of having two large wake vorticies, we have four smaller ones. One immediate problem that came to mind waas vortex wing interaction issue with the tailplane. Since vortices do stick to the surface due to being spools of lower pressure, maybe the downwash may carry them underneath, I don't know for sure.

Engine placement however gave me a headache. It seems whether they would be place inboard or outboard of the raked step in the wing, they would have to be oriented such that the intake aims more down and inwards than they are on airplanes now. I'm not certain about sticking the engines in the rear, a la DC-9. Issues may be similar to the tailplane discussed above.

My personal preference, without doing any airflow analysis, I'd place the ngines underwing and inward of the step. I.e. for the right wing pictures the engine would be left of the step, like the pylon would be right at the corner.

[Edited 2006-04-06 05:45:24]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
 
viv
Posts: 2953
Joined: Tue May 31, 2005 5:17 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Thu Apr 06, 2006 9:35 pm

I see only a red 'x', so cannot comment.
Nikon D700, Nikkor 80-400, Fuji X Pro 1, Fujinon 35 f/1.4, Fujinon 18 f/2
 
joness0154
Posts: 650
Joined: Sat Nov 19, 2005 12:56 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Thu Apr 06, 2006 10:34 pm

Here's my problems with a design like that:

Fuel tanks?
Leading edge devices?
Wing chord?

Basically, any benefit from this would be negated by having to add weight for the complex stuff needed for it all to work out....

[Edited 2006-04-06 15:35:46]
I don't have an attitude problem. You have a perception problem
 
pilotaydin
Posts: 2100
Joined: Tue Sep 07, 2004 12:30 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 12:23 am

Won't the mini change in sweepback cause it's own local drag? thus cancelling any reduced drag from the design itself?

and will that short chord after the taper produce less lift? needing to make the roots of the wing thicker?

Other than that, let's get testing!!
The only time there is too much fuel onboard, is when you're on fire!
 
Skyslave
Posts: 44
Joined: Sat Oct 22, 2005 12:52 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 12:29 am

Any chance you could host that picture through image shack? http://imageshack.us/

Its not comming up for me.
 
User avatar
HAWK21M
Posts: 30067
Joined: Fri Jan 05, 2001 10:05 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 1:01 am

Quoting Lehpron (Thread starter):
Engine placement however gave me a headache



Quoting Lehpron (Thread starter):
My personal preference, without doing any airflow analysis, I'd place the ngines underwing and inward of the step. I.e. for the right wing pictures the engine would be left of the step, like the pylon would be right at the corner

Wouldn't Outbd of the Step be more logical.Inbd if righ near the step would negate its very purpose.Just my thought.I would have thought Tail mounted powerplants too.

What about LED distribution.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
OldAeroGuy
Posts: 3918
Joined: Sun Dec 05, 2004 6:50 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 4:27 am

I think you will have a difficult making the second planform's induced drag be as low as the first planform.

Sectional lift coefficients on the outboard wing for the second planform will also be an issue.

Economically, the second wing would never be adopted.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
greasespot
Posts: 2968
Joined: Sat Apr 24, 2004 10:48 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 6:19 am

It is one thing to shoot the idea down....But aviation is full of "it will never work contraptions"....

This is what the wow factor is.....Someone has an idea and goes with it....

I think that we have missed a lot by being born now in this airplane world. Back in the 50's it seemed that if you had an idea someone would try and build it....

That is what is cool about aviation....

GS

PS...look at how excited we were when the 787 was first concepted...then the "ugggh" when it was changed to look like a regualr plane...
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"
 
Staffan
Posts: 3879
Joined: Tue Mar 18, 2008 9:21 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 7:22 am

Quoting Greasespot (Reply 7):
I think that we have missed a lot by being born now in this airplane world. Back in the 50's it seemed that if you had an idea someone would try and build it....

It has much to do with the fact that it's considered better to evolutionize than to revolutionize. Introducing to many big changes at once, may give you some bad surprises down the road.

The aviation industry growing, but the number of fatal accidents aren't. And that's no coincidence.
 
Boeing7E7
Posts: 5512
Joined: Sat Jul 31, 2004 9:35 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 8:35 am

Quoting Lehpron (Thread starter):
I came up with this idea maybe last week, please criticize. I have not done any CFD analysis or anything, this is fresh out of my mind and mainly done with thought experiments and MS paint.

Where possible, put the heavies on a 3.00 degree approach glideslope and the non-heavies above them on a 3.30 degree slope. If you need CAT II/III put them on 2.80 and 3.10.

[Edited 2006-04-07 01:36:31]
 
rolfen
Posts: 1539
Joined: Tue Jan 17, 2006 6:03 am

RE: My Proposal For Reducing Impact Of Wake Vortic

Fri Apr 07, 2006 9:46 am

What about putting vertical separations on the wing to reduce the spanwise flow? Sort of what the caravelle had, but more angled, with the front being closer to the fuselage and the back being further away.

Your design seems ok, but from my limited knowlegde, I feel that leaking part of the flow will sort of short-circuit the the wing and might require bigger wings for the same load.

[Edited 2006-04-07 03:11:10]
rolf
 
joness0154
Posts: 650
Joined: Sat Nov 19, 2005 12:56 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 12:25 pm

Quoting Boeing7E7 (Reply 9):
Where possible, put the heavies on a 3.00 degree approach glideslope and the non-heavies above them on a 3.30 degree slope. If you need CAT II/III put them on 2.80 and 3.10.

Well you'd need 4 different Glideslope antenna's then. Thats 4x the cost of what it is already, 4x the maintenance, etc. Then you'd need 4 different frequencies. It'd get out of hand real fast!

If you put people on a 2.8 glideslope you might not have adequate obstacle clearance, etc.....and people on a 3.3 degree slope would have to chop and drop.... not good for the engines.
I don't have an attitude problem. You have a perception problem
 
WingedMigrator
Posts: 1771
Joined: Wed Oct 26, 2005 9:45 am

RE: My Proposal For Reducing Impact Of Wake Vortic

Fri Apr 07, 2006 1:52 pm

Quoting Lehpron (Thread starter):
In a real airplane application setting, instead of having two large wake vorticies, we have four smaller ones.

Before we get all Navier-Stoked... let's get back to basics.

Nobody has yet pointed out that to first order, the strength of the wake is determined not so much by the wing shape, but instead by the aircraft's mass and how slow it's moving.

In order to stay aloft, an aircraft must shove downwards a large flow of air. This is simple conservation of momentum, and no voodoo aerodynamics need be invoked to explain this. The magnitude of this flow (per unit distance) depends on

1) mass. The more massive the aircraft, the more air it has to shove downwards, and the stronger the wake.

2) speed. If the amount of air shoved downwards per unit time is proportional to mass, and if the speed diminishes, then the amount of air shoved downwards per unit distance increases, and the stronger the wake.

So, to first order, the strength of the wake is given by how big and how slow. There's no way around that.

Then come the aerodynamic tricks, having to do with making the wake vortices, inevitably produced by the downward flow, dissipate as quickly as possible. But keep in mind these are only second order effects...
 
speedracer1407
Posts: 330
Joined: Fri Dec 24, 2004 4:19 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 5:19 pm

This subject is pretty far out of my league, but I'd like to take a shot at it anyway.

In order to support a large aircraft with Lephron's proposed wing, the pan wouldn either need to be greately increased to account for the sudden reduction in chord, or the inboard chord would need to be very thick indeed. Since wing span is the most likely limiting factor given current airport terminal limitations, it seems that the inboard section of Lephron's wing would need of an enormous chord length, and thus bear the vast brunt of the lifting duties. Wouldn't the midspan vortices on this wing be, therefore, severe enough to reduce or eliminate the advantages of dividing wake turbulence/vortices along the span in the first place?

O
Dassault Mercure: the plane that has Boeing and Airbus shaking in their boots.
 
viv
Posts: 2953
Joined: Tue May 31, 2005 5:17 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 5:51 pm

Quoting WingedMigrator (Reply 12):
In order to stay aloft, an aircraft must shove downwards a large flow of air.

Ummmm, not so.

Lift comes from the pressure differential between the upper and lower surfaces of the wing. This pressure differential occurs because the upper surface is convex, so that air passing over the wing has to travel further than air passing under it.
Nikon D700, Nikkor 80-400, Fuji X Pro 1, Fujinon 35 f/1.4, Fujinon 18 f/2
 
Staffan
Posts: 3879
Joined: Tue Mar 18, 2008 9:21 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 6:47 pm

Quoting Viv (Reply 14):
Ummmm, not so.

Lift comes from the pressure differential between the upper and lower surfaces of the wing. This pressure differential occurs because the upper surface is convex, so that air passing over the wing has to travel further than air passing under it.

How can a longer travel distance above the wing the way you describe result in a pressure difference?

Answer: It can't.

As the air is deflected downwards by the wing, a lower pressure region will appear on top of the wing. It's this lower pressure that accelerates the air over the top. The wing's lift is proportional to the amount of air that is deflected downwards. Newtons third law.

[Edited 2006-04-07 11:48:53]
 
joness0154
Posts: 650
Joined: Sat Nov 19, 2005 12:56 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 7:05 pm

Quoting Staffan (Reply 15):
How can a longer travel distance above the wing the way you describe result in a pressure difference?

Answer: It can't.

A little picture I made while drunk

I don't have an attitude problem. You have a perception problem
 
Staffan
Posts: 3879
Joined: Tue Mar 18, 2008 9:21 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 7:16 pm

In your sketch, why does the air aft of the trailing edge not have an angle downwrds? With air moving horizontally under the airfoil meeting up with air at a downward angle from the top of the airfoil, wouldn't it be logical that the resulting flow would have a slight downward angle? That downward flow would be proportional to the airfoil's produced lift.

The venturi theory is flawed:
http://www.grc.nasa.gov/WWW/K-12/airplane/wrong3.html

[Edited 2006-04-07 12:17:33]
 
joness0154
Posts: 650
Joined: Sat Nov 19, 2005 12:56 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Fri Apr 07, 2006 7:30 pm

Quoting Staffan (Reply 17):
In your sketch, why does the air aft of the trailing edge not have an angle downwrds? With air moving horizontally under the airfoil meeting up with air at a downward angle from the top of the airfoil, wouldn't it be logical that the resulting flow would have a slight downward angle? That downward flow would be proportional to the airfoil's produced lift.

Cause I was drunk when I drew it  Smile it will flow downwards.....haha

They say the venturi model is flawed, but this is the lame explanation they give:

"Lift occurs when a moving flow of gas is turned by a solid object. The flow is turned in one direction, and the lift is generated in the opposite direction, according to Newton's Third Law of action and reaction. Because air is a gas and the molecules are free to move about, any solid surface can deflect a flow. For an aircraft wing, both the upper and lower surfaces contribute to the flow turning. Neglecting the upper surface's part in turning the flow leads to an incorrect theory of lift."

That is the weakest theory I've heard. Coming from NASA no doubt.

But theories are theories, and there are always more than one so i'd happily believe another one if it could be explained to me...
I don't have an attitude problem. You have a perception problem
 
Skyslave
Posts: 44
Joined: Sat Oct 22, 2005 12:52 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 12:08 am

Quoting Staffan (Reply 17):
In your sketch, why does the air aft of the trailing edge not have an angle downwrds? With air moving horizontally under the airfoil meeting up with air at a downward angle from the top of the airfoil, wouldn't it be logical that the resulting flow would have a slight downward angle? That downward flow would be proportional to the airfoil's produced lift.

The venturi theory is flawed:
http://www.grc.nasa.gov/WWW/K-12/air....html

Heh, I think you need to read up on Bernoulli's Principle. If you dont want to take the time, he basically states that the higher the velocity, the lower the pressure. Although newtons 3rd does create lift, Bernoulli's principle also contributes. There are some wing designs, however, that dont use Bernoulli's principle, like a aerobatic wing. They have a cemetrical camber so when flying inverted there is no uneven liftage.

edit: Also, the air moving along the bottom of the wing meeting up with the air at top of the wing doesnt create any lift. By the time air joins back together aft of the wing, the lift process is done for that "unit" of air. The downward deflection comes from the angle of incidence between the airframe and airfoil (Airplane longitudinal Axis vs. The chord line).

[Edited 2006-04-07 17:14:38]

[Edited 2006-04-07 17:27:17]
 
grandtheftaero
Posts: 247
Joined: Sat Nov 29, 2003 1:05 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 3:08 am

Quoting Viv (Reply 14):
Lift comes from the pressure differential between the upper and lower surfaces of the wing. This pressure differential occurs because the upper surface is convex, so that air passing over the wing has to travel further than air passing under it.

*SIGH* Yet another innocent life lost because someone was mishandling Bernoulli's principle. How much more can we take? Think of the children!
 
User avatar
Jetlagged
Posts: 2564
Joined: Sun Jan 23, 2005 3:00 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 4:07 am

Quoting Skyslave (Reply 19):
Although newtons 3rd does create lift, Bernoulli's principle also contributes. There are some wing designs, however, that dont use Bernoulli's principle, like a aerobatic wing. They have a cemetrical camber so when flying inverted there is no uneven liftage.

How do these wings "know" when to use Newtons laws or Bernoulli's theorem  

BTW remember to use spell check next time (cemetrical) and what on earth is liftage?

The answer is that both concepts explain lift and can be used interchangeably. You can't add the two effects together! What is wrong is to use the venturi idea to explain the change in velocity over a wings surface. Bernoulli's theorem does not properly explain the velocity changes, but it does correctly predict the pressure distribution that arises.

Note, for a venturi, the velocity change is calculated using the continuity equation:

density * area * velocity = constant

Bernoulli's equation can then be used to calculate static pressure changes.

A flat plate basically produces lift by momentum change (Newtonian), but there is also a pressure differential between upper and lower surfaces. You can measure the lift with pressure tappings or a force gauge and get the same answer.

Please, no more Newton versus Bernoulli arguments and keep the simplified explanations of lift out of supposedly serious posts.

Regarding Lephron's wing proposal, the structures people would have nightmares. Such drastic changes in planform would seriously affect structural strength and fatigue resistance. Straight taper to the outboard section would be better, rather than that sudden kink.

[Edited 2006-04-07 21:12:24]
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 5:49 am

Long wings = vortices far apart = good and efficient / weak vortices.

Short wings = vortices close = bad and inefficient / strong vortices.

You have basically created half a short wing combined with half a long wing. Sorry.  Smile
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
Boeing7E7
Posts: 5512
Joined: Sat Jul 31, 2004 9:35 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 6:16 am

Quoting Joness0154 (Reply 11):
Well you'd need 4 different Glideslope antenna's then. Thats 4x the cost of what it is already, 4x the maintenance, etc. Then you'd need 4 different frequencies. It'd get out of hand real fast!

You set up the glideslope for the prefered glideslope angle and use GPS for the other. Eventually LAAS for both.

Quoting Joness0154 (Reply 11):
If you put people on a 2.8 glideslope you might not have adequate obstacle clearance, etc.....and people on a 3.3 degree slope would have to chop and drop.... not good for the engines.

Where practical. Plenty of major airports out there without obstructions that can accomodate 2.80 vs the existing 3.00.

[Edited 2006-04-07 23:18:23]
 
User avatar
Starlionblue
Posts: 19879
Joined: Fri Feb 27, 2004 9:54 pm

RE: My Proposal For Reducing Impact Of Wake Vortic

Sat Apr 08, 2006 6:31 am

Quoting Viv (Reply 14):
Lift comes from the pressure differential between the upper and lower surfaces of the wing. This pressure differential occurs because the upper surface is convex, so that air passing over the wing has to travel further than air passing under it.

Ouch, painful. But I must admit you see this flawed view of lift in many respectable encyclopedias and taught in many high school physics classes. Shame on them.

Having said that, the principle is not entirely wrong. I found this explanation for lift: http://travel.howstuffworks.com/airplane5.htm (read on for a few pages). It's the only one I have found so far that explains lift in easy terms without a lot of math (though in the end they admit that you pretty much need math to get an accurate result). This passage summarizes the problem:

If you read any college-level aerodynamics textbook, you will find plenty of mathematical methods for calculating lift. Unfortunately, none of these explanations are particularly satisfying unless you have a Ph.D. in mathematics.

There are many simplified explanations of lift that appear on the Internet and in some textbooks. Two of the most popular explanations today are the Longer Path explanation (also known as the Bernoulli or equal transit time explanation) and the Newtonian explanation (also known as the momentum transfer or air deflection explanation). While many versions of these explanations are fundamentally flawed, they can still contribute to an intuitive understanding of how lift is created.


[Edited 2006-04-07 23:32:25]
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
Jetlagged
Posts: 2564
Joined: Sun Jan 23, 2005 3:00 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 6:31 am

Quoting Boeing7E7 (Reply 9):
Where possible, put the heavies on a 3.00 degree approach glideslope and the non-heavies above them on a 3.30 degree slope. If you need CAT II/III put them on 2.80 and 3.10.

That won't make much difference to the problem, especially closer to the threshold, where a 0.3 degree difference in glideslope angle makes just over 5 feet difference vertically.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
lehpron
Topic Author
Posts: 6846
Joined: Tue Jul 10, 2001 3:42 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 8:20 am

Nice to see what looks like health discussion on fresh ideas.  Wink

Quoting Pilotaydin (Reply 3):
Won't the mini change in sweepback cause it's own local drag? thus cancelling any reduced drag from the design itself?

The intended purpose of this idea was not to reduce drag, but toInitially, This wing proposal was supposed to be the same drag and thus performance, etc.

Quoting HAWK21M (Reply 5):
Wouldn't Outbd of the Step be more logical.Inbd if righ near the step would negate its very purpose

Yeah I see what you mean. Any spanwise flow would technically run up against the engine. But if that was the case, then it would seem the spanwise flow outboard of any engine in the quad-jet setup would support all of the vortex...! Unless the outboard wing on those aircraft outboard of the #1 and #4 engines were repplaced with giant raked wingtips, that just sounds weird, I don't know about that.

Quoting OldAeroGuy (Reply 6):
Economically, the second wing would never be adopted

maybe not any time soon, I was speaking from an aerodynamics perspective.

Quoting OldAeroGuy (Reply 6):
I think you will have a difficult making the second planform's induced drag be as low as the first planform.

Sectional lift coefficients on the outboard wing for the second planform will also be an issue.

Upon thinking of ways to make it work, may I pose another question: What is the velocity of the spanwise flow at the tip of a generic wing? It is a vector quantity, so coupled with freestream, it should be less than the speed of sound. Knowing the variation of spanwise velocity would help in determining if/how this could work. How would you do it?

Quoting Boeing7E7 (Reply 9):
Where possible, put the heavies on a 3.00 degree approach glideslope and the non-heavies above them on a 3.30 degree slope. If you need CAT II/III put them on 2.80 and 3.10.

Would varying the approach angle be the cheaper route? Granted, the proposal is with respect to approach, not cruise.

Quoting WingedMigrator (Reply 12):
Nobody has yet pointed out that to first order, the strength of the wake is determined not so much by the wing shape, but instead by the aircraft's mass and how slow it's moving.

I get the impression of an idealized wake if actual wing shape doesn't greatly affect it. My current common sense (which is growing) tells me if I don't use a wing and go for a lifting body, I'd see a change in wake pattern. What am I missing?

Quoting Jetlagged (Reply 21):
Straight taper to the outboard section would be better, rather than that sudden kink.

I can't picture that completely, could you draw something or find an example online?  Smile

Quoting FredT (Reply 22):
Long wings = vortices far apart = good and efficient / weak vortices.

Short wings = vortices close = bad and inefficient / strong vortices.

You have basically created half a short wing combined with half a long wing. Sorry

Aspect ratio...hey I tried. Big grin
The meaning of life is curiosity; we were put on this planet to explore opportunities.
 
Boeing7E7
Posts: 5512
Joined: Sat Jul 31, 2004 9:35 pm

RE: My Proposal For Reducing Impact Of Wake Vortices

Sat Apr 08, 2006 11:06 am

Quoting Jetlagged (Reply 25):
That won't make much difference to the problem, especially closer to the threshold, where a 0.3 degree difference in glideslope angle makes just over 5 feet difference vertically.

There's a 20' difference in the threshold crossing height between the types of aircraft that would use each slope, dictated by the slope. The higher slope woudl be at Aircraft arrive at that cross point and effectively flare to a standard 3.0 slope at the threshold and beyond to touchdown. This is how the FAA intends to mediate much of the problem in conjunction with ADS-B so obviously it works. The higher TCH used by smaller aircraft would cause them to touch down about 800' further down the runway than the aircraft on the lower slope.

Quoting Lehpron (Reply 26):
Would varying the approach angle be the cheaper route? Granted, the proposal is with respect to approach, not cruise.

More than likely. In cruise with free flight, it's not a major issue because of flexible routing.
 
OldAeroGuy
Posts: 3918
Joined: Sun Dec 05, 2004 6:50 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Sun Apr 09, 2006 3:44 am

Quoting Lehpron (Reply 26):
Quoting OldAeroGuy (Reply 6):
Economically, the second wing would never be adopted

maybe not any time soon, I was speaking from an aerodynamics perspective.

And my reply is from an aerodynamic perspective. The second wing is uneconomic based on higher induced drag alone, not to mention the structural and construction issues. Ponder FredT's reply.

Quoting FredT (Reply 22):
You have basically created half a short wing combined with half a long wing. Sorry.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
Staffan
Posts: 3879
Joined: Tue Mar 18, 2008 9:21 am

RE: My Proposal For Reducing Impact Of Wake Vortices

Sun Apr 09, 2006 6:54 am

Quoting Skyslave (Reply 19):
Heh, I think you need to read up on Bernoulli's Principle

Thanks, will do  Wink

Who is online

Users browsing this forum: No registered users and 11 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos