futuristic aircraft wing configurations

Futuristic Aircraft Wing Configurations

1. INTRODUCTION

On 17 December 1903, at a little after 1030 in the morning, a winged contraption made

of canvas, wood and wire began to move along a rail placed on a freezing, gale-lashed

sand flat in North Carolina. As a tiny petrol engine strained to turn the machine's twin

propellers, it gained speed and its wings began to generate lift. As the force increased

and overcame the craft's weight, Orville and Wilbur Wright's Flyer took to the air.It

remains one of the greatest moments in technological history. But with the success of

that first flight of a powered, heavier-than-air craft - all 12 seconds of it - it would be

tempting to think that the pair of Ohio bicycle mechanics had solved aviation's

engineering problems. But now, in the second century of powered flight, aviation

engineers are still battling to find better ways to solve some of the very same problems

the Wrights faced, and many others of which the pair could never have dreamed.

Apart from evolutionary improvements in conventional aircraft, revolutionary changes

are possible when the "rules" are changed. This is possible when the configuration

concept itself is changed and when new roles or requirements are introduced. Varous

agencies concerning aviation in indulged in research and development of various

aircraft configurations and core development in most of this research is based upon the

revolutionary wing design concepts and incorporation of new technologies to bring life

some of the innovative aircrafts which can be able to replace the existing aircraft

models and there by improving various aspects of both the civil aviation as well as the

military combact situations lieing ahead in the future.

.

1SNGCE,Kadayirippu Dept of mechanical engineering


2. AIRCRAFT WING BASICS

2.1 FORCES ON AIRCRAFT

Fig 2.1 Basic forces on an aircraft

.Lift

Lift is produced by a lower pressure created on the upper surface of an airplane's wing

compared to the pressure on the wing's lower surface, causing the wing to be "lifted"

upward. The special shape of the airplane wing (airfoil) is designed so that air flowing

over it will have to travel a greater distance faster, resulting in a lower pressure area

thus lifting the wing upward. Lift is that force which opposes the force of gravity (or

weight).

Fig 2.2 Generation of lift force



Thrust

Thrust is a force created by a power source which gives an airplane forward motion. It

can either "pull" or "push" an airplane forward. Thrust is that force which overcomes

drag. Conventional airplanes utilize engines as well as propellers to obtain thrust.

Drag

Drag is the force which delays or slows the forward movement of an airplane through

the air when the airflow direction is opposite to the direction of motion of the airplane.

It is the friction of the air as it meets and passes over and about an airplane and its

components. The more surface area exposed to rushing air, the greater the drag. An

airplane's streamlined shape helps it pass through the air more easily.

Aspect ratio

The aspect ratio is the span divided by the mean or average chord. [3] It is a measure of

how long and slender the wing appears when seen from above or below.

Low aspect ratio - short and stubby wing. More efficient structurally, more

maneuverable and with less drag at high speeds. They tend to be used by fighter

aircraft, such as the Lockheed F-104 Straighter, and by very high-speed aircraft

(e.g. North American X-15).

Moderate aspect ratio - general-purpose wing (e.g. the Lockheed P-80

Shooting Star).

High aspect ratio - long and slender wing. More efficient aerodynamically,

having less drag, at low speeds. They tend to be used by high-altitude subsonic

aircraft (e.g. the Lockheed U-2), subsonic airliners (e.g. the Bombardier Dash 8)

and by high-performance sailplanes (e.g. Glaser-Dirks DG-500).

2.2 FUNCTIONS OF A WING

The primary functions of an aircraft wing can be listed out as follows:-

For stability & control

For landing

Increase the coefficient of lift

For safely achieving 1. Rolling 2. Yawing 3. Pitching


http://wapedia.mobi/en/Glaser-Dirks_DG-500

http://wapedia.mobi/en/Bombardier_Dash_8

http://wapedia.mobi/en/Lockheed_U-2

http://wapedia.mobi/en/P-80_Shooting_Star


http://wapedia.mobi/en/North_American_X-15

http://wapedia.mobi/en/F-104_Starfighter

http://wapedia.mobi/en/Mean_(mathematics)

http://wapedia.mobi/en/Aspect_ratio

http://www.allstar.fiu.edu/aero/proptypes.htm


Without wings aircrafts will have a lot of drag, with a very little lift .

Fig 2.3 Basic aircraft motions

2.3 SIGNIFICANCE OF WING SHAPE

The design of an airplane wings plays an important role in deciding the purpose for

which the airplane will be used in a later stage. The shape and design of the wings also

play a vital role in deciding the operation of the plane.

Airplane wings are so designed that it makes the plane airborne by producing the

necessary lift. In order to take the plane into the air, the wings should produce a lift

force which is more than the total weight of the airplane. Different forces act on the

airplanes which eventually assist it to become airborne. However, when it comes to

wings, a combination of Bernoulli’s and Newton's principles help in generating the

necessary air lift for plane.

The shape of the wings is as important as the shape of the fuselage. For example, high-

speed jets have narrow, swept-back wings. The narrow wings are used because these

planes have tremendous thrust and so do not need large wing areas to produce lift. The

sleek wing design allows fast jet planes to travel through the air with minimal

resistance. Single-engine planes have broad, rectangular wings. Broader wings are used

to enhance lift on smaller planes with less powerful thrust. In short, the shape of an

aircraft depends largely on the speed at which it will fly. This is why still a large chunk

of the money spend on aircraft design improvement is spend of research on wing design

in agencies such as NASA, ONERA and DLR.



2.4 SWEPT WINGS: A BREAK THROUGH IN MODERN AVIATION

The fact that intercontinental air travel with acceptable flight times is an everyday

occurrence today is due to an apparently simple idea: the swept wing. Seventy years

ago, the advantages of a swept wing in comparison to an unswept or straight one was

experimentally demonstrated for the first time at the Aerodynamics Research Institute

(Aerodynamische Versuchsanstalt; AVA) in Göttingen, the precursor of today's German

Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR).

In the 1930s, the fastest aircraft of the time hit an invisible limit: the sound barrier. As

soon as aircraft came anywhere near this barrier, they became increasingly difficult to

control. The rudders stopped responding, the wings began to vibrate and the whole

aircraft was thoroughly shaken up. Aircraft frequently crashed as a consequence.

Because of this, many researchers believed that sustained flight speeds of 800 to 900

kilometres per hour, commonplace today, were impossible.

Significance only recognised in Germany

In 1935, Adolf Busemann, who studied under the Göttingen aeronautics research

pioneer Ludwig Prandtl, presented the idea of the swept wing at a congress in Italy.

However, the suggestion of this 34-year-old, unknown in the scientific community,

was ignored.

Adolf Busemann In his book 'Die Pfeilflügelentwicklung in Deutschland bis 1945'

(The Development of the Swept Wing in Germany until 1945), Meier describes how

the significance of the new invention as the basis for high-speed flight was only

recognised in Germany. "One reason for this was undoubtedly the search for

superior weapons systems for the impending war," Meier says. The new wing

promised German fighter aircraft a speed advantage in comparison to their

opponents.

Faster with swept wings

Hubert Ludwieg In late 1939, Hubert Ludwieg carried out the first swept-wing

measurements at AVA. Busemann had, in the meantime, become head of the new

German Institute of Aviation Research (Deutsche Forschungsanstalt für Luftfahrt;

DFL) in Braunschweig. Ludwieg's measurements confirmed the correctness of

Busemann's theory for the first time. A swept wing allows an aircraft to fly faster

because the drag is reduced.



If, then, the swept wing was the prerequisite for high-speed and supersonic flight,

the jet engine provided the necessary power. In 1939, the first jet aircraft in the

world took to the skies in the shape of the Heinkel 178. Swept wings and jet

propulsion were combined in an aircraft for the first time in 1944, in the Junkers

287, based on the research undertaken at Göttingen. Interestingly, the latter had

wings that were swept forward – a concept that has only been recently revived, due

to its difficult flight characteristics.

Knowledge-transfer to the USA

In contrast to jet propulsion, the swept wing was not used during the Second World

War. Models such as the legendary first operational jet aircraft, the Messerschmitt

262, did not have swept wings. This was because this new wing shape also

produced many problems. Lift and stability are worse than for unswept wings.

At the end of the War, the Allies secured the knowledge acquired in Germany for

themselves: The German researchers were obliged to commit everything they knew

to paper. Adolf Busemann, the inventor of the swept wing, went to the USA, where

he continued his research, first at NASA and then as a professor at the University of

Colorado in Boulder.

Basis of modern aviation

Forerunner of modern passenger jets: Boeing 707 The discoveries made in Germany

became the basis of modern aviation. The Americans combined the results in the

B47 jet bomber. This in turn was the precursor of the Boeing 707, which introduced

the age of civilian jet travel. All of today’s giant civilian airliners are based on the

B707. A direct line can be drawn from Busemann’s swept wing idea via the Junkers

287 to modern aircraft such as the Airbus 380.Today, the former wartime enemies

are working together in the field of swept-wing research. In an international project

to test modern computational techniques, the aerospace research institutions of the

USA, France and Germany (NASA, ONERA and DLR) have recently created a

comprehensive experimental database for a wind tunnel model of a commercial

airliner.

.



3. SOME BASIC AIRCRAFT WING CONFIGURATIONS

Wing shapes of an aircraft can be defined in many ways in some cases the

distinction between types is blurred, for example the wings of many modern combat

aircraft may be described either as cropped compound deltas with (forwards or

backwards) swept trailing edge, or as sharply tapered swept wings with large "Leading

Edge Root Extension" (or LERX).

All the configurations described have flown (if only very briefly) on full-size

aircraft, except as noted. Some variants may be duplicated under more than one

heading, due to their complex nature. This is particularly so for variable geometry and

combined (closed) wing types.

Wings may be swept forwards or back for a variety of reasons. A small degree of

sweep is sometimes used to adjust the centre of lift when the wing cannot be attached in

the ideal position for some reason. Other uses are described below.

Straight - extends at right angles to the line of flight. The most efficient

structurally, and common for low-speed designs, such as the P-80 Shooting Star.

Swept back -. From the root, the wing angles backwards towards the tip. At

transonic speeds swept wings have lower drag, but can handle badly in or near a

stall and require high stiffness to avoid aero elasticity at high speeds. Common on

high-subsonic and supersonic designs e.g. the English Electric Lightning.

Forward swept - the wing angles forwards from the root. Benefits are similar to

backwards sweep, also at significant angles of sweep it avoids the stall problems

and has reduced tip losses allowing a smaller wing, but requires even greater

stiffness and for this reason is not often used. A civil example is the HFB-320

Hansa Jet.

Some types of variable geometry vary the wing sweep during flight:

Swing-wing - also called "variable sweep wing". The left and right hand wings

vary their sweep together, usually backwards. Seen in a few types of combat

aircraft, the first being the General Dynamics F-111.

Oblique wing - a single full-span wing pivots about its mid point, so that one

side sweeps back and the other side sweeps forward. Flown on the NASA AD-1

research aircraft.


http://wapedia.mobi/en/NASA_AD-1

http://wapedia.mobi/en/Oblique_wing

http://wapedia.mobi/en/General_Dynamics_F-111

http://wapedia.mobi/en/Variable-sweep_wing

http://wapedia.mobi/en/Variable_geometry

http://wapedia.mobi/en/HFB-320_Hansa_Jet

http://wapedia.mobi/en/HFB-320_Hansa_Jet

http://wapedia.mobi/en/Forward-swept_wing

http://wapedia.mobi/en/English_Electric_Lightning

http://wapedia.mobi/en/Aeroelasticity

http://wapedia.mobi/en/Transonic

http://wapedia.mobi/en/Swept_wing



Fig 3.1 Straight wing Fig 3.2 Swept wing Fig 3.3 Forward swept wing

Fig 3.4 Variable sweep wing Fig 3.5 Oblique wing

Combined or closed wing - two wings are joined structurally at or near the tips in

some way. This stiffens the structure, and can reduce aerodynamic losses at the tips.

Variants include:

Box wing Annular box wing Flat annular wing Cylindrical wing.

Fig 3.6 Combined or closed wing shapes

Delta - triangular plan form with swept leading edge and straight trailing edge.

Offers the advantages of a swept wing, with good structural efficiency. Variants are:

Tailless delta Tailed delta Cropped delta Compound delta Ogival delta

Fig 3.7 Delta wing shapes


http://wapedia.mobi/en/Delta_wing

http://wapedia.mobi/en/Closed_wing

http://wapedia.mobi/en/Closed_wing


Some designs have no clear join between wing and fuselage, or body. This may be

because one or other of these is missing, or because they merge into each other:

Flying wing - the aircraft has no distinct fuselage or tail empennage (although

fins and small pods, blisters, etc. may be present).

Blended body or blended wing-body - smooth transition between wing and

fuselage, with no hard dividing line. Reduces wetted area and hence, if done

correctly, aerodynamic drag. The McDonnell XP-67 Bat was also designed to

maintain the aerofoil section across the entire aircraft profile.

Fig 3.8 Flying wing Fig 3.9 Blended wing


http://wapedia.mobi/en/XP-67_Bat

http://wapedia.mobi/en/Wetted_area

http://wapedia.mobi/en/Blended_wing_body

http://wapedia.mobi/en/Flying_wing


4. WING CONFIGURATIONS FOR THE FUTURE

On 17 December 1903, at a little after 1030 in the morning, a winged contraption made

of canvas, wood and wire began to move along a rail placed on a freezing, gale-lashed

sand flat in North Carolina. As a tiny petrol engine strained to turn the machine's twin

propellers, it gained speed and its wings began to generate lift. As the force increased

and overcame the craft's weight, Orville and Wilbur Wright's Flyer took to the air.It

remains one of the greatest moments in technological history. But with the success of

that first flight of a powered, heavier-than-air craft - all 12 seconds of it - it would be

tempting to think that the pair of Ohio bicycle mechanics had solved aviation's

engineering problems. But now, in the second century of powered flight, aviation

engineers are still battling to find better ways to solve some of the very same problems

the Wrights faced, and many others of which the pair could never have dreamed.When

we think about what may appear in future aircraft designs, we might look at recent

history. The look may be frightening. From first appearances, anyway, nothing has

happened in the last 40 years!

Apart from evolutionary improvements in conventional aircraft, revolutionary changes

are possible when the "rules" are changed. This is possible when the configuration

concept itself is changed and when new roles or requirements are introduced.

Here are some o the most promising aircraft wing configurations concepts which seems

to be the future of the modern generation aviation.

OBLIQUE FLYING WING

BLENDED WING BODY

JOINED WING

MORPHING WING

Even though there maybe some other wing configutrations proposed by researchers for

future of aviation .I have choosen these four aircraft wing configurations for the study

because they offer the most promising future and have been subjected to research and

analysis by various institutions like NASA and various other aviation experts as

fututristic wing configuration .



5. OBLIQUE FLYING WING

One of the more unusual aircraft designs ever proposed, an Oblique Flying

Wing (OFW) is composed almost entirely of a single wing and one or more jet engines.

That in itself is not so odd, as there have been many flying wing vehicles in both

practical use and as test models throughout the last seventy years or so. However, in

supersonic flight, one tip of the Oblique Flying Wing is designed to sweep back while

the other is angled forward. In other words, the wing flies forward with its body angled

asymmetrically into its direction of flight.

Fig 5.1 Oblique wing on a NASA-AD1

Experiments with oblique wing flight go back to the 1940s, and in the last 30

years NASA has created a number of experimental aircraft of varying sizes and designs

to test the soundness of the concept. Northrop-Grumman in cooperation with DARPA

was building an experimental OFW X-plane in order to more fully test the concept, but

the project was cancelled in 2008. However, the concept seems sound, and work on it

may one day be revived.

The OFW uses the same principles as the variable geometry wing, only as its

entire body is its lifting surface, it sweeps its full-vehicle wing back at supersonic

velocities so that one tip is angled forward and the other back, allowing it to fly

asymmetrically. At subsonic speeds it would fly with its body-wing perpendicular to its

direction of flight like a traditional airplane, and then sweep its body-wing back at an

angle the faster it goes.

The engines the OFW mounts are gimballed to allow them to stay oriented in

the proper direction of flight no matter how much the wing sweeps forward or back.

They are also placed strategically on the body to act somewhat as rudders to help with

stability. Some early OFW test models had one or more vertical fins on the trailing 11

SNGCE,Kadayirippu Dept of mechanical engineering


wing edge to help with stability; the tailless Northrop-Grumman version eschewed

these for sophisticated computer controls similar to those used in the B-2 bomber, also a

tailless flying wing.

Ideally, an OFW would be a very efficient vehicle from low up to hypersonic

speeds, allowing it much greater fuel economy, range, and endurance at all stages of

flight than most other transonic aircraft. It was these capabilities that made it very

attractive as an Air Force project. It would have been capable of a high speed

supersonic dash to its target area, and then could loiter over it for a potentially long

time. This would make them ideal for use as recon UAVs (Unmanned Aerial Vehicles),

similar to the Global Hawk, but could reach the target area and begin surveillance or

execute a tactical strike much faster. They could also be used for manned fighting

vehicles, though that capability is probably considerably farther off than their potential

use as drones. The first working oblique wing model was a NASA-Ames (1976)

remotely piloted vehicle which performed from wing angles of 0 to 45 degrees

5.1 FUNDAMENTAL ADVANTAGES

Minimal Lift Induced Drag at all Regimes

Lift Induced Drag is inversely proportional to Aspect Ratio In the case of

Oblique Aspect Ratio is high (about twice that for a conventional swept back

wing).

Fig 5.2 Comparison of wing span & wing length between conventional and oblique

wing



Structural Stability

The straight carry-through structure of the oblique wing geometry avoids

torques that are sometimes reacted by fuselage structure and makes for a simpler

structure to manufacture. If variable sweep is incorporated in the design, the

oblique wing's single pivot in tension provides structural advantages when

compared with two pivots that must carry large bending loads in a conventional

variable-sweep design.

Fig 5.3 Comparison of forces devloped at joining of wing sections between

conventional and oblique wing

Another significant advantage of the oblique wing arrangement for supersonic

flight is that it distributes the lift over about twice the wing length as a

conventional swept wing of the same span and sweep, which provides a

reduction in lift-dependent wave drag by a factor of 4. At low supersonic speeds

(for which these simple scaling laws apply), the volume wave drag of the wing

is only 1/16th that of the symmetrically-swept wing of the same span, sweep,

and volume.

Other features unique to oblique wing designs may make them well-suited for

particular missions. Examples of this include efficient storage and/or deck

spotting that may be appealing to Navy aircraft.

The oblique flying wing configuration benefits from span-loading in the same

way as other all-wing concepts, but it is particularly appealing because large



changes in sweep may be achieved with rather simple (by comparison) motions

of nacelles and control surfaces.

5.2 CHALENGES OF THE OBLIQUE WING

The oblique wing's problem over the years has been the control challenge posed

by the unique coupling between the asymmetric aircraft's aerodynamic and aero

structural modes. "Any time it came close, another configuration that was nearly as

good would be selected because of the perceived risk for a manned aircraft," says

Stephen Morris who, as a graduate student at Stanford University, built and flew the

small oblique flying-wing model for NASA. "It's ideal for an unmanned aircraft."

COUPLING ACTION-makes controlling difficult

PIVOTING ENGINE INLET AND NOZZLE-thrust vectoring becomes an issue

PIVOT DESIGN CONSTRAINTS-not easy to rotate a wing at supersonic speeds

DYNAMIC AEROELASTIC PHENOMENA -flutter and buffeting is observed

5.3 IMPLEMENATION

So far, only one manned aircraft, the NASA AD-1, has been built to explore this

concept. It flew a series of flight tests starting in 1979.

Fig 5.4 NASA AD-1 (An oblique wing configuration aircraft)

Another aircraft so far produced is Northrop Grumman Switchblade

The Switchblade is a proposed unmanned aerial vehicle being developed by Northrop

Grumman for the United States. The United States Defence Advanced Research

Projects Agency (DARPA) has awarded Northrop Grumman a US$10.3 million


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

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

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

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

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



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

http://en.wikipedia.org/wiki/NASA_AD-1

http://en.wikipedia.org/wiki/1979_in_aviation

http://en.wikipedia.org/wiki/NASA_AD-1


contract for risk reduction and preliminary planning for an X-plane oblique flying wing

demonstrator.[1]

Fig 5.5 Northrop Grumman Switchblade

The program aims at producing a technology demonstrator aircraft to explore the

various challenges which the radical design entails. The proposed aircraft would be a

purely flying wing (an aircraft with no other auxiliary surfaces such as tails, canards or

a fuselage) where the wing is swept with one side of the aircraft forward, and one

backwards in an asymmetric fashion.[2] This aircraft configuration is believed to give it

a combination of high speed, long range and long endurance. [3] The program entails two

phases. Phase I will explore the theory and result in a conceptual design, while Phase II

will result in the design, manufacture and flight test of an aircraft. The outcome of the

program will result in a dataset that can then be used when considering future military

aircraft designs.

Flight of the Switchblade is scheduled for 2020 and will cruise with its 61-meter long

oblique wing perpendicular to its engines like a typical aircraft. As the aircraft increases

speed, the wing begins to pivot, so that when it breaks the sound barrier, its wing has

swivelled 60 degrees, with one wingtip pointing forward and the other backward. The

change in aerodynamics and the general structure makes the plane very difficult to

control for a human being. The plane is totally controlled by an onboard computer,

which handles appropriately all the parameters needed for maintaining a stable flight

during the mission

A dual hull passenger aircraft is also been developed which will be a oblique flying

wing passenger aircraft.15


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

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

http://en.wikipedia.org/wiki/Northrop_Grumman_Switchblade#cite_note-2


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

http://en.wikipedia.org/wiki/Canard_(aeronautics)


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


Fig 5.6 A dual hull passenger aircraft concept

Another future project by Oblique Wing is to develop An Oblique Flying Wing

Passenger Aircraft which is also is also under development in NASA Dryden Langley

research center .

Fig 5.7 Oblique Flying Wing Passenger aircraft concept



6. BLENDED WING BODY

The Blended-Wing-Body (BWB) is a revolutionary concept for commercial aircraft1-2.

It requires a design approach that departs from the conventional decomposition of the

airplane into distinct pieces and instead integrates wing, fuselage, engines, and tail to

achieve a substantial improvement in performance. The BWB is related to the flying

wing, but is a somewhat more sophisticated concept that resulted from a study to

determine the optimum low-drag shape to contain a given volume of passenger space.

The resulting fuselage resembles a flattened sphere that tapers down and blends into the

outboard wings, hence the name Blended-Wing-Body.

Fig 6.1 Stealth bomber B2 Fig 6.2 Blended wing body model in NASA

Flying wing designs are defined as having two separate bodies and only a single

wing, though there may be structures protruding from the wing. Blended wing/body

aircraft have a flattened and airfoil shaped body, which produces most of the lift to keep

itself aloft, and distinct and separate wing structures, though the wings are smoothly

blended in with the body.

The BWB was first created by the commercial aircraft division of McDonnell

Douglas (MDD), a firm that was purchased by Boeing in the mid-1990s. Though

Boeing expressed little interest in continuing most of MDD's projects, they have shown

the foresight to carry on low-level development of the revolutionary BWB. An early

aircraft exhibiting BWB design principles was the Stout Batwing. The desinger William

Bushnell Stout, toured the country promoting aircraft of the future would not have

fuselages. The Miles M.30 "X Minor" of the early 1940s was an experimental aircraft

for research blended wing fuselage designs for an envisaged large airliner.


http://en.wikipedia.org/wiki/Miles_M.30

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

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

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



One of the beauties inherent in a BWB airliner is it strength. It readily absorbs

both cabin pressure and wing bending loads, and in recent tests in the Stanford

University wind tunnel, a 6% scale model easily passed all extreme flight envelope

tests.

The BWB concept reduces the load on the outboard wing section airfoils, while the

large centerbody chord provides enormous strength, requiring a much low sectional lift

coefficient. This reduced lift demand allows the large thick profile of the centerbody to

hold passengers and cargo, without exacting a high compressibility drag penalty. Due

to its shape and structure, typical shocks evident on the thinner outboard wing panels

become very weak on the centerbody.

Fig 6.3 Structural overview of proposed Boeing X-48

Blended wing body configuration is one of the greatest topic put to extensive research

and study in the field of civil aviation nowadays . Currently, both NASA and Boeing

are exploring BWB designs under the designation X-48.[2] Studies suggest that BWB

aircraft, configured for passenger flight, could carry from 450 to 800 passengers and


http://en.wikipedia.org/wiki/Blended_wing_body#cite_note-1

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

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

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


achieve fuel savings of over 20 percent. NASA has been developing, since 2000, a

remotely controlled model with a 21 ft (6.4 m) wingspan..

Fig 6.4 An overview of seating capability of BWB design

If ever a design represented innovation matched with utility, this one is the

embodiment of that concept. According to intensive, well-reasoned calculations, the

aircraft they propose would carry 800 passengers over a 7,100 nautical mile range and

be ready to enter service in the year 2010. Quite an accomplishment considering that its

fuel burn will be 27% lower than its conventional Airbus A3XX rival, with a take off

weight 15% lower. Empty weight will be 12% less. It will only require three instead of

four engines, and will match or exceed conventional performance, despite having 27%

less thrust. Those factors combined with 20% better lift/drag capability translates to the

phenomenal savings in fuel already mentioned.

With a double-decked interior cabin located in the central portion of the

blended wing, the extension serves to stiffen, buttress and extend structural integrity

and aerodynamic overlap to the entire wing structure. The blended wing layout also

serves as a very resilient bending structure, dramatically reducing the cantilever span of

the thin wing section, distributing weight along the span more efficiently. This reduces

the peak bending moment and shear to half that of a conventional configuration. Its

shape also reduces total wetted area, or those portions of the aircraft which come in

contact with the air. In this imaginative layout there is no need for a conventional tail.


http://www.twitt.org/bldwing.htm#four


Unlike standard configurations, the blended wing's outboard leading edge slats are the

only high lift devices required and, because the three buried engines aft of the central

wing structure ingest the wing's boundary layer airflow.

In this deign the fuselage is not only a wing, but a mounting for the engines that power

it, along with their inlets, as well as a pitch control surface. By continuing to blend and

smooth the streamlined disk, with a bullet nose added for enhanced visibility from the

flight deck, the designers have come up with an aircraft that will fly at Mach .85, with

an optimized wing loading fully 33% lower than that of conventional large size, long-

range aircraft with less passenger carrying capacity. Since the wing blending hides

most of the trapezoidal wing within the centerbody of the aircraft, the cost of wing area

on drag is greatly lessened.

In layman's terms, the low effective wing loading of the BWB meant that exotic

high lift systems are not needed. A leading edge slat is necessary on the outboard wing,

but all trailing edge devices are simple hinged flaps, which also serve as elevons. Low

wing loading reduces control power demands. The small winglets provide primary

directional stability and control, and split drag rudders, similar to those found on the B-

2 bomber, are used for low-speed, engine-out conditions.

In addition to performance, comfort and capacity, the BWB concept has an inherently

low acoustic signature. Exhaust noise will not be reflected off the wing's undersurface.

There is little additional airframe noise caused by complex mechanism, such as slotted

flaps. The aft location and staggered positions of the engines lessens the possibility of

shards and debris from a failed powerplant penetrating the pressurized cabin or fuel

tanks, destroying flight controls or causing the remaining engines to fail. Compared to

conventional cylindrical tube fuselages, the center body pressure vessel of the BWB is

much stronger, thus improving chances of survival in a crash.

6.2 CHALLENGES OF THE BWB

Radically different from conventional aircraft configurations, the BWB presents

special design challenges. Where the design of conventional aircraft can be divided

between different disciplines, no discipline can work independently on the BWB.

Where configuration can set the fuselage and aerodynamics can set the wing on a

conventional aircraft, the two disciplines are forced to work together in defining a low-

drag wing that adequately encloses the payload on the BWB. In that task, the large



number of geometric degrees of freedom coupled with a number of geometric and

aerodynamic considerations present a substantial problem. Adding consideration of

weight, balance, stability, and control issues turns this into an challenge.

Disadvantages and design challenges of the BWB shape also include less inherent

flight stability than the tube design, less structural suitability for internal pressurization

(it's easier to pressurize a tube than a wider, oval cross-section like the BWB's), a lack

of passenger side windows, and a layout that moves passengers and cargo off the

aircraft's centerline, which exaggerates the vertical motion felt when the plane rolls to

turn.

Further increasing the challenge, the BWB has unique design features that require

higher fidelity modelling than might be acceptable for conventional designs. To enclose

the payload within the wing, the BWB has very thick airfoil sections over its body.

Attaining low drag, transonically, with these airfoils is an aerodynamic challenge. In

this region, the wing structure doubles as pressure vessel for the cabin, presenting flat

panels that must support pressure loads over large spans dictated by the cabin

arrangement. Designing and analyzing these panels and assessing a weight for them is a

substantial challenge for structures and weights disciplines. To reduce drag, the design

is tail-less, but this creates interesting challenges for stability and control: first, to

balance the airplane and provide sufficient control power, and second, to ensure that

control deflections for trim do not adversely affect the spanload and hence the drag. A

final challenge lies in the aft-mounted engines and the difficulties with propulsion and

airframe integration. Before undertaking a credible effort on the BWB, some of these

issues had to be addressed with new analysis methods.

6.3 IMPLEMENATION

Will such an aircraft ever be built? That's the decision the manufacturer will

have to make. But if a large subsonic aircraft to take the place of the 747 is really

needed, it appears that the BWB concept offers the most for the necessary investment.

It's lighter, more commodious, more fuel efficient, requires far less power, and is

certainly more aesthetic in appearance. True, looks aren't everything, but that old

aviation adage still holds true, "If it looks good, it will fly good," and the BWB aircraft,

in addition to much improved economy, simplicity and handling, certainly has any

potential flying watermelon beaten hands down.



The BWB was first created by the commercial aircraft division of McDonnell

Douglas (MDD), a firm that was purchased by Boeing in the mid-1990s. Though

Boeing expressed little interest in continuing most of MDD's projects, they have shown

the foresight to carry on low-level development of the revolutionary BWB. However,

Boeing has not yet provided any indication that the design will go into full-scale

development or production. While such an aircraft could potentially reduce operating

costs significantly, concerns have been raised about compatibility with existing airport

infrastructure and the difficulty of evacuating so many people from the deep interior

cabin in an emergency. In addition, many airlines are worried that passengers may be

unwilling to fly an aircraft that is so different looking from what they are used to.

Perhaps because of these concerns, the most likely application for a BWB design in the

near future is a military transport or refueling tanker rather than a commercial airliner.

NASA has been funded to test a subscale version of the BWB called the X-48 to

evaluate the feasibility of the idea.

Fig 6.5 Experimental model of the Boeing X-48


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


7. JOINED WING

THE joined-wing airplane may be defined as an airplanethat incorporates tandem wings

arranged to form diamondshapes in both plan and front views. Joined wings differ from

conventional wings in their internal structure as well as their external configuration.

Fig 7.1 Sample Total Joined Wing Configuration Concept

The joined wing is concept that could provide enhanced maneuverability . A joined-

wing aircraft has its tail wing swept forward to be joined with the rearward swept main

wing so that the wings form a diamond when viewed from the top or head-on.

Fig 7.2 Various Joined-Wing Viewing Angles



Recent events such as Operation Iraqi Freedom and the conflict in Afghanistan have

shown an increased interest in the use of unmanned aerial vehicles (UAVs), particularly

as surveillance-type platforms. UAVs seem especially suited for intelligence or

surveillance/reconnaissance (ISR) missions, which require many hours of continuous

coverage at high altitudes. One ISR concept, known as SensorCraft, includes missions

such as targeting, tracking, and foliage penetration (tanks under trees). Several of these

missions require large antennas, and some demand 360 degree coverage. All of these

requirements, but especially the endurance, demand the use of a UAV. Several

configurations are currently being considered for the SensorCraft mission. A

conventional vehicle, similar to Global For this effort, , the joined-wing. Such a design

lends itself to continuous 360-degree coverage, while possibly providing weight savings

and improved aerodynamic performance over a conventional vehicle.


The research and analysis of Joined Wing designs by various agencies like NASA fids

that the Perceived advantages of this configuration are

LIGHT WEIGHT

The joined wing can offer great weight savings based on a number of factors.

Just comparing a joined wing with a single wing that has the same airfoil, equal

induced drag, and taper ratios, the joined wing is about 24% lighter than the

single wing plane.

Joined wing to have less wing wetted area than the single wing and still achieve

the same lift as the single wing plane. The less area can also go towards a large

weight reduction.

HIGH STIFFNESS

Since the two wings form a box-like structure, they tend to prevent each other

from bending or twisting. This gives the joined wing a very high stiffness, both

torsionally and flexurally. The tip deflection of the single wing can be up to 2.8

times that of the joined wing when both systems experience equal vertical

loading at the same lift to drag ratio. This can be attributed to the stiff, box-like

structure of the joined wing system.

LOWER INDUCED DRAG



The induced drag on the joined wing is lower than the single wing when

comparing systems of equal lift, span, and dynamic pressure. Two factors

make this possible. First, the incorporated swept wing desin artributes of

joined wing, swept wings tend to have a higher induced drag.The large

dihedrals used for reducing the weight also help reduce the induced drag.

STABLITY AND CONTROL

One of the obvious benefits of the joined wing is the availability of more

control surfaces than the typical single wing.

Fig 7.3 Controlling forces acting on joined wing structure

With the control surfaces on each wing, there are added maneuverability and

control capabilities. Direct lift control and direct side force control can be

achieved.Since the joined wing has effectively four places for control surfaces

as compared with two for a single wing, the joined wing can offer more

stabilizing features. Because of the great stability of this configuration, there is

no longer the need for the tail to be so far downstream in order to produce a long

moment arm. Thus, the fuselage can be shortened, thereby reducing the weight a

great deal.

Because of the great stability of this configuration, there is no longer the need

for the tail to be so far downstream in order to produce a long moment arm.

Thus, the fuselage can be shortened, thereby reducing the weight a great deal.

Unfortunately, the advantages of the joined wing decrease as its wing area is

reduced. It has also been shown that among the different joined wing



configurations, the swept forward/swept rearward (SFSR) system can travel

13.8% farther that the standard joined wing [14]. If it is necessary to fly at low

altitudes, the joined wing plane is more maneuverable than the single wing

plane, especially when flying above 3g’s. It is best to keep in mind that not all

advantages can be gained at once. There is a lot of optimization and design that

must be done.

SHORT-TAKE-OFF AND LANDINGS

The apparent almost equal lift from bothsurfaces implying the potential to be

extremely high lift designs. That could be translated into short-take-off and

economic fight performance.

7.2 CHALLENGES

Eventhough all the above mentioned advantages make this wing configuration an good

future aircraft design it also possess some dis advantages mainly in the role of military

aviation in acombat situation. The joined wing cannot sustain /any/ damage to ANY of

it's airfoil group without essentially destiffening the entire structural interlock. Since we

are now dealing with missiles that throw out proximity fuzed fragment and blast kill

mechanization on the order of a dozen times more total lethality than a WWII gun

system, the reality remains pretty high, IMO, that you just _would not want_ to expose

this aircraft to any kind of seriously strenuous as much as damage-intensive combat

environment. Because you load a thin wing and then cut it at any given point, and it will

fold completely..

Also since there are no tails in a joined wing and the hollow wing will likely have

limited gust response in a close combact situation like in dogfight where the

survivability is determined in more than 100th fractions of a second.

7.3 IMPLEMENTATION

Recent events such as Operation Iraqi Freedom and the conflict in Afghanistan

have shown an increased interest in the use of unmanned aerial vehicles (UAVs),

particularly as surveillance-type platforms.



Fig 7.4 An AFRL joined wing UAV “sensocraft”

UAVs seem especially suited for intelligence/surveillance/reconnaissance (ISR)

missions, which require many hours of continuous coverage at high altitudes. One ISR

concept, known as SensorCraft, includes missions such as targeting, tracking, and

foliage penetration (tanks under trees). Several of these missions require large antennas,

and some demand 360 degree coverage. All of these requirements, but especially the

endurance, demand the use of a UAV. Several configurations are currently being

considered for the SensorCraft mission. A conventional vehicle, similar to Global

Hawk, is a possibility. For this effort, however, the joined-wing configuration is

studied. A key aspect of the Sensorcraft requirement is to have AESA as load-bearing

structures, typically in the wing. That is the primary reason two out of the three

proposal feature joined-wings of sorts.

During the 1980’s, Julian Wolkovitch was a leading expert and advocate of the

joined wing . Today, many companies and organizations are continuing his work to

make the joined wing configuration a flying reality. Lockheed Martin is looking to

incorporate the joined wing design on the next generation tankers. The hope is that the

joined wing tanker, designated the New Strategic Aircraft, will be able to carry more

fuel and have a two-boom system, thereby allowing the Air Force to refuel more planes

with fewer tankers. A radio-scaled model has flown eleven successful flights, validating

Lockheed Martin’s choice of the joined wing configuration.



Fig 7.5 Lockheed martins’s joined wing tanker concept

An interesting variation on the joined-wing is Boeing’s “fluid wing” which combines a

swept wing with a forward-swept wing but both are on the same plane.

Fig 7.6 A Fluid wing experimental aircraft by boeing

Despite all of this research into the joined wing configuration, there is still much to

learn and study and no aircraft have ever been built by joined wing configuration other

than the experimental aircraft for research and analysis.



8. MORPHING WING TECHNOLOGY

Like a bird, the world's very first airplane had flexible wings. The lightweight

wood, cloth, and wire flyer, built by Wilbur Wright and Orville Wright and first flown

on Dec. 17, 1903, was steered and stabilized by pulleys and cables that twist the

wingtips. Some aviation historians say that this bird-inspired control mechanism was

the pivotal innovation that enabled the Wright brothers to achieve heavier-than-air

flight whereas others pursuing that same goal had failed. Although the Wright brothers

control strategy worked, it vanished quickly from aviation. Stiff wings became the

standard because they could withstand greater forces associated with increased flying

speeds and vehicle weights. To control the sturdier aircraft, designers added movable

panels to the ends of those stiffwings. Those panels manipulate the airflow and thus the

aero-dynamic forces that pilots use to make an airplane take off, turn, or change

altitude. Now, at the centennial of powered human flight, the original technique for

controlling aircraft is in the midstMORPHING aircraft, , are aircraft utilizing wings that

have the capability to drastically change plan form shape during flight .This type of

design might be incorporated to enhance various operational capabilities of the aircraft,

reduce the aircraft’s required takeoff gross weight, and/or enable an aircraft to fly a

design mission that a fixed-wing aircraft could not.

FIG 8.1 A morphing wing design by NASA in various flying conditions

The desire for multi-mission capability in military and civil air vehicle systems has

created a need for technologies that allow for drastic wing shape changes during flight.

Since most current aircraft are fixed-geometry, they represent a design compromise

between conflicting mission segment performance requirements, such as high-speed

cruise, low-speed loiter, and low turn radius maneuver. If a hybrid aircraft is designed 30


http://www.thefreedictionary.com/in+the+midst


to combine several flight profiles, the wing design must maximize overall efficiency of

the anticipated mission. Through morphing, the aerodynamics of the aircraft can be

adapted to optimize performance in each segment by changing areas such as the camber

of the airfoils and the twist distribution along the wing.

Adapting the shape of wings in flight allows an air vehicle to perform multiple,

radically different tasks by dynamically varying its flight envelope. The wing can be

adapted to different mission segments, such as cruise, loitering, and high-speed

maneuvering by sweeping, twisting, and changing its span, area, and airfoil shape.

Morphing wing technology is considered to be a key component in next-generation

unmanned aeronautical vehicles (UAVs) for military and commercial applications.

8.1 BIOLOGICAL INSPIRATION

While we struggle to develop new artificial compounds, nature offers us a helping hand.

Ten Dutch and Swedish scientists, based in Wageningen, Groningen, Delft, Leiden, and

Lund, have shown how "wing morphing" makes swifts such versatile flyers. Their study

proves that swifts can improve flight performance by up to three-fold numbers that

make wing morphing the next big thing in aircraft engineering.

Swifts are some of the most efficient birds when it comes to active flying (flapping the

wings instead of just gliding). They spend nearly their entire lives in the air, eating,

mating and even sleeping in flight. The common swift travels 4.5 million kilometres

(2.8 million miles) in its lifetime, roughly the same as six round trips to the Moon or

100 times around the Earth. Researchers have proved how these master aviators change

the shape of their wings to improve performance, providing clues as to how aircraft

engineers can improve their designs. They looked at 15 pairs of real swift wings taken

from dead birds from sanctuaries by placing them in a wind tunnel and varying their

orientation to measure the effect of wing shape and position on flight efficiency.



Fig 8.2 A morphing wing comparison with abird

Scientists learned that flying slowly with extended wings gives swifts maximum flight

efficiency. But swept wings deliver a better aerodynamic performance for flying fast

and straight. Swept wings are also better for fast and tight turns; but this time swept

wings are better because they do not break as easily as extended wings.

They found that swifts could adjust the shape of their wings to increase the efficiency of

their glide or to make faster turns.

Extended wings provided the best slow glide, whereas those swept back away from the

head functioned better at high speeds. Extremely fast turns required swept-back wings,

as extended wings had the tendency to break under the extreme force. Elsewhere,

swept-back wings did not flutter; they protected against bone fractures under these

conditions of high force.

Findings further revealed that a proper co-ordination of the wings in relation to each

activity allowed the birds to fly 60 percent further in a single glide and improve their

turning efficiency by three times.

8.1 ADVANTAGES

If aircraft wing shapes can be designed to change and adapt to constantly

changing conditions of flight. Or, an aircraft can mimic the way a bird lands, greatly

decreasing the amount of fuel and runway space required.

Flying high and slow—an appealing capability for reconnaissance missions—

requires a wide wingspan in addition to a larger wing area, so increasing the wingspan

by 50 percent to 75 percent also multiplies applications. “The aircraft could hang out at



high altitudes, but it could still respond supersonically or at least high subsonically to a

threat. This is a big deal for the military.

By using this technology we can one day liberate aircraft from flaps, slats, and

ailerons so that they more closely emulate the astonishing adaptability and control of

bird flight.

Going beyond wings that merely flex, scientists and engineers have also been

developing aircraft surfaces capable of molding themselves from one shape into

another, much as arm muscles bulge and flatten. These possibilities arise largely from

the use of so-called smart materials, a broad range of substances that can shorten, Even

on a modest scale, such reshaping of aircraft contours could greatly enhance vehicle

control and performance.

Looking yet further down the air lanes, far more drastic and complicated

transformations--for instance, wings that can telescope, curl, or fold--may be on the

way, yielding extraordinarily versatile airplanes and missiles that change their shapes

according toIf research programs that are just starting eventually reveal that such large-

scale morphing is feasible, the first of those aircraft may streak across the skies 20 to 30

years from now.

In a world of energy crisis and green house gases and other pollution issues this

concept provides a great way to cut the fuel consumption as well as there by cutting the

emissions of the aircraft during its flight which may be an more vital issue considering

the fact that this concept is still in its most primary state and if ever this concept comes

in action which the researchers are saying is going to be atleast 20 to 30 years.

8.3 CHALLENGES

Along with the great advantages presented by this new Morphing Wing

Technology the very factors that what gives the morphing wing technology presents a

great deal of challenges too. The most basic challenge is the design aspects of the

building of the wings which will be able to undergo drastic changes in mid flight

conditions.

Due to he morphing of the wings the wing design principles would consist of

integrated systems using morphing mechanisms, propulsion systems, control systems,


http://www.thefreedictionary.com/according+to


structures, and materials. the figure below demonstrates one of the company’s

completely new designs for the underlying structure of a morphing aircraft wing.

Fig 8.3 Sliding rib concept

A “sliding rib” concept for the underlying structure of a morphing wing. This

represents a new design philosophy for wing structures. Morphing wing design requires

the integration of mechanical structure, seamless skin, and actuators. To reshape wings

during flight requires arrays of tiny but powerful devices called compact hybrid

actuators. . These motors use a piezoelectric material - one which deforms slightly when

an electric field is applied to it. Apply the field repeatedly and the motor can be made to

ratchet along a toothed track, pushing or pulling a section of wing as it goes. Small

piezoelectric motors could sit inside a wing and deliver force where it is needed.

But shape-shifting will create another headache: any gaps that appear as you

open up a joint in a wing will cause drag. And if an aircraft is travelling at supersonic

speeds, the stresses this drag creates could rip a wing apart. So DARPA is looking at a

new generation of "shape memory" materials that might stretch and move with the

wings, sealing joints as they open and close

The other major challenges include Morphing Wing technology presents is

maintaining aerodynamic balance when the air craft changes its shape in mid air during

flying.When an aircraft folds its wings on the fly, rapid, large shifts occur in its canter

of gravity and another balance point known as the aerodynamic canter. Such shifts,

absent among conventional fixed-wing aircraft, could make the plane spin or become

otherwise unmanageable.

Very intense research is been going on to overcome and to reduce the various

challenges presented by Morphing Wing in various research centers like NASA and

various other institutions concerning aviation sector.



8.3 IMPLEMENTATION

The Morphing Wing aircraft is in its very primary stage of development process.

Various institutions such as NASA , BOEING and various other compnies are

conducting several tests by means of prototype models and computer aided analysis

Although morphing is a recent aeronautical term that describes these relatively new

technologies, in a general sense it describes changes in vehicle state and shape. In the

broadest sense of the term, shape morphing has been used with ever-increasing

effectiveness since the Wright brothers. For instance, changing wing camber by

twisting the wing as the Wright brothers did, or using control surfaces as almost all

aircraft do to this day, can be construed to be shape morphing to enable improved

performance at different flight conditions maneuver, take-off, high angle of attack, etc.

As a further example, a retractable landing gear alters the shape of the aircraft to reduce

drag during flight. And perhaps the most effective implementation of shape morphing is

variable sweep wings as exemplified by the F-111, B-1, and F-14 aircraft.

Fig 8.4 F-111 with variable sweep wing configurations

The Defense Advanced Research Projects AgencyDARPA decided to revisit the

morphing aircraft concept in April 2002 with a three-phase program. The first two

phases of the MAS program aimed at attaining four technical goals: innovative, active

wing structures that change shape; integration and aeronautical use of advanced sensors,

skin and structure materials, internal mechanisms and distributed power sources;


http://encyclopedia2.thefreedictionary.com/Defense+Advanced+Research+Projects+Agency


advanced capabilities for the military community; and advanced shape-changing

materials, efficient actuators and sophisticated, smart mechanisms.

Two flight-traceable morphing wing concepts were developed through Phase II of

Defense Advanced Research Projects AgencyDARPA’s Morphing Aircraft Structures

(MAS) program.2 The first, a “folding wing” concept, was developed by Lockheed

Martin and enables variations of span length, aspect ratio, and effective sweep angle.

The second, a variable sweep / variable root chord concept, was developed by NextGen

Aeronautics and enables direct variations in root chord length and sweep angle;

indirectly varying the plan form area and aspect ratio. Both of these are illustrated in the

following figure.

Fig 8.5 Lockheed Martin’s Folding Wing Concept

Fig 8.6 NextGen Aeronautic’s Variable Sweep / Variable Root Chord Concept

Phase II of the MAS program concentrated on development and testing of scaled wind

tunnel models to determine system feasibility in flight equivalent environments (wind

tunnel experiments at the TDT at NASA, Langley), Phase III will pursue the

development of these concepts as flight demonstrational vehicles. Clearly, application

of morphing wing technologies will require the concurrent development of design and

optimization strategies at the .

Phase III of this is programm which will completely test the scaled models of morphing

wing aircrafts .which is advancing in present time.


http://encyclopedia2.thefreedictionary.com/Defense+Advanced+Research+Projects+Agency


Much more radical morphing is just beginning to come off some aeronautical engineers'

drawing boards. As a starting point, several companies are exploring major wing

transformations.

Although the Wright brothers launched morphing research a century ago, that

engineering approach has caught on only in the past few years. With many aeronautical

designers now bent on applying all the , know-how and technological progress of the

last century to the task, a new phase of aviation may be taking off.


http://www.thefreedictionary.com/aeronautical


9. CONCLUSION

The future of the aircraft desingn looks to be far more promising and complex. There

are a lot of research going on in the overall design of the aircraft far more aggressively

and promises a great change in future aircraft design. Most of the changes in the inthe

aircraft design accompanies the above mentioned various wing configurations as one of

the primary acepects of advancements, by analysing these various wing configurations

we could conclude that in coming years to come entire look of an aircraft will change

drastically.

In the field of civil aviation the introduction of Blended Wing Body will replace the

today’s conventional aircrafts. If the research by Boeing is heading into the right

direction we could see and get into one of these within a decade .

In the field of UAV’s i think the Joined Wing configuration is most likely to take

over although the stealth of these have to be improved drastically.

Also the Oblique Wing configuration if the testing of models such as Northrop

Grumman Switchblade goes al well then the the it can also be a good wing

configuration for future combact UAV’s.

Even though the Morphing Wing concept is yet to take wings in a substantial way,it

sure promises to be one of the most futuristic advancements in aviation. If the

various research programmes goes all well the Morphing wing Technology will be

the future iof theaviation i cvill aviation aswell as the military combact aircrafts due

to its ada[ptablity and its inherent features



REFERENCE

1. Aeroelasticity of Nonconventional Airplane Configurations—Past and Future ,

JOURNAL OF AIRCRAFT Vol. 40, No. 6.

2. I. Kroo Stanford University, U.S.A.VKI lecture series on Innovative

Configurations and Advanced Concepts for Future Civil Aircraft

3. Liebeck, R. H., Rawdon, B. K., “Blended-Wing-Body Subsonic Commercial

Transport,” AIAA Paper 98-0438,

4. J. Wolkovich “The Joined-wing: An Overview,” Journal of Aircraft, Vol. 23, No. 3,

, pp. 161- 178,

5. Michael D. Skillen and William A. Crossley Modeling and Optimization for

Morphing Wing Concept Generation Purdue University, West Lafayette, Indiana

_NASA archives

6. http://www.century-of-flight.net

7. http://science.howstuffworks.com

8. http://www.google.co.in

9. http://www.aviationspectator.com/resources/aircraft-profiles


futuristic aircraft wing configurations

Documents