DESIGN AND CONSTRUCTION OF A  FLYING AIRCRAFT CARRIER MADE OF SUPER WOOD AND CARBON FIBER POWERED BY ANTI GRAVITY PROPULSION

Depending upon mission needs, the ship can be outfitted with different modules that include:
■Manned aircraft, such as a helicopter and flight crew

 ■Manned and X-45 Unmanned Combat Air Vehicle (UCAV

■Amphivious assault ship armed with laser, SAM and anti ship missles

Manned and Unmanned Combat Air Vehicle

Maybe the title’s “antigravity spaceship” aim is too high (it’s a long way ’till there), but Tesla, followed by other scientists along the last century, discovered the principle of propulsion using strong electromagnetic fields. It’s not about traveling on the ground, but from the ground up, with extraordinary speed and ease.
The entire document is posted on panaceauniversity.org/D8.pdf, here is a short description of what the “spaceship” does and how it can be built, as described by Patrick J. Kelly (update: the document I mentioned in 2008 doesn’t exist anymore) :
“Tesla performed an experiment in which he applied high-voltage high-frequency alternating current to a pair of parallel metal plates. He found that the ‘space’ between the plates became what he described as “solid-state” exhibiting the attributes of mass, inertia and momentum. That is, the area transformed into a state against which a mechanical push could be exerted. This implied that, using this technique, it should be possible to produce a spaceship drive anywhere in space, if the mechanism for thrusting against the ‘solid-state’ space could be determined. Further experiments convinced Tesla that powerful electromagnetic waves could be used to push against (and pull against) what appears to be ’empty space’. The drive principle is based on the Hall-effect used in semiconductor magnetic sensors, and is called the magnetohydrodynamic (“MHD”) effect. This might be illustrated like this:












Here, a box is constructed with two metal plates forming opposite sides and two insulating plates holding them in position and surrounding an area of ‘space’. High-frequency, high-voltage alternating current is applied to the metal plates and this creates an electric field “E” acting between the plates as shown in black.

A magnetic field “B” is generated by the electrical field. The magnetic field acts at right-angles to the electric field, as shown in blue. These two fields produce a propulsion thrust “F” shown in red in the diagram. This propulsion force is not produced by ejecting any matter out of the box, instead, it is produced by a reaction against the ‘solid-state’ condition of space-time caused by the high-frequency electromagnetic pulsing of that area of space. This is enormously more effective than a jet engine. The thrust increases with the fourth power of the frequency, so if you double the frequency, the effect is sixteen times greater.

To put this into perspective, consider the force being applied against gravity to lift an object into the air. The force pulling the object downwards is gravity and its strength is given by:

Gravitational force:

F = g x M x m / r2

where

G is the gravitational constant (6.672 x 10-8 cm3 g-1 s-2)

M is the mass of the first body

m is the mass of the second body and

r is distance between the two centres of mass

The lifting force is given by:

Lorentz Force: Force on an object = Electric force + Magnetic force

F = q x E + q x v x B

where

q is the charge on the object,

B is the magnetic field,

v is the velocity of the object and

E is the electric field

How do these forces compare? Well, the electromagnetic force is stronger than the gravitational force by a factor of about 2,200,000,000,000,000,000,000,000,000,000,000,000,000 times. That number (2.2 x 1039) is too big for anybody to really visualise, so let me put it another way.

If the amount of energy used to mechanically lift an object a distance of one hundredth of an inch (one quarter of a millimetre) off the ground, were used as an electromagnetic lifting force, then that amount of energy would lift the object more than 3,472,222,000,000,000,000,000,000 miles off the ground, or in metric units, more than 5,588,001,700,000,000,000,000,000 kilometres off the ground. This kind of drive is an entirely different kind of animal. This Hall-effect type of drive if used in a spaceship would require only a very small amount of input power to drive the ship at great speeds and over great distances.

As the device shown above operates directly on the space-time field which penetrates all matter, there would appear to be no reason why it should not be used to drive a conventional vehicle by positioning it in a horizontal position rather than the vertical position shown in the diagram. Throttle operation could be by very slight adjustment to the frequency of the AC pulses applied to the metal plates. However, Bill Lyne indicates that horizontal movement is better achieved by producing Tesla’s very short, high-voltage high-frequency DC pulses at the front of the vehicle while at the same time generating very high-voltage high-frequency AC waves at the back of the vehicle. This style of drive is said to pull the vehicle along rather than push it along.

Tesla’s Dynamic Theory of Gravity (1897) states that all bodies emit microwaves whose voltage and frequency are determined by their electrical contents and relative motion. He measured the microwave radiation of the earth as being only a few centimetres in wavelength. He said that the frequency and voltage were influenced by the velocity and mass of the earth, and that its gravitational interaction with other bodies, such as the sun, was determined by the interaction of the microwaves between the two bodies.

If you find the concept of producing a driving force through pushing against the space-time continuum to be difficult to accept, then perhaps you should consider the US Patent granted to Boris Volfson on 1st November 2005. The important thing about this patent (which is crammed full of long words) is not whether or not it presents a realistic mechanism for a practical space drive, but the fact that the US Patent Office in the year 2005, granted the patent after what presumably was careful consideration. With that in view, it is hardly possible to consider Tesla to have been totally confused when he designed (and built) his “electric flying machine” which operated by pushing against the space-time field.

Tesla used high voltage at gigahertz frequencies for his electropulsion system. The propulsion of a vehicle powered by a Tesla drive is by the use of an additional AC generator at the back (which stiffens the space-time continuum behind the vehicle) and a DC ‘brush’ generator at the front (which weakens the space-time continuum in front, causing the vehicle to be pulled forwards).

Tesla was very astute. He deduced that ’empty space’ actually contained:

1. Independent carriers which permeate all space and all matter and from which all matter is made. These carry momentum, magnetism, electricity or electromagnetic force, and can be manipulated artificially or by nature.

2. ‘Primary Solar Rays’ (starlight) which travel at the speed of light, having frequencies far above X-rays, gamma and UV radiation.

3. ‘Cosmic Rays’, particles in space propelled by the Primary Solar Rays.

4. X-rays, Gamma rays and UV electromagnetic waves, all of which travel at the speed of light.

5. Ordinary visible and Infra-Red electromagnetic waves which travel at the speed of light.

6. Rapidly varying electrostatic force of enormous potential, emanating from the earth and other gravitational bodies in space.

When we grasp the actual nature of the universe, it becomes clear that we have a much larger range of opportunities for producing usable energy in large quantities and at minimal cost.”

MATERIALS OF CONSTRUCTION

For anti gravity propulsion Dielectric Materials or, insulating material which is a very poor conductor of electric current is needed for the body of the ship. When dielectrics are placed in an electric field, practically no current flows in them because, unlike metals, they have no loosely bound, or free, electrons that may drift through the material. Instead, electric polarization occurs.

Dielectric typically means materials with a high polarizability. The latter is expressed by a number called the relative permittivity. The term insulator is generally used to indicate electrical obstruction while the term dielectric is used to indicate the energy storing capacity of the material (by means of polarization). A common example of a dielectric is wood which  is the electrically insulating material between the metallic plates of a capacitor. The polarization of the dielectric by the applied electric field increases the capacitor's surface charge for the given electric field strength.

Super wood that is so strong it can stop a bullet and is as robust as STEEL could be the building material of the ship. Engineers boiled blocks of regular wood in a chemical solution to soften them. These were then pressed between heated metal plates at extreme pressures. This increasing its density threefold while reducing its thickness by 20 per cent. The resulting material was able to stop a projectile in its tracks during tests. Super wood that is as robust as steel and six times lighter could be a renewable construction material for the future, according to scientists. Planks of the reinforced lumber, which researchers have compared to carbon-fibre, could be used to create anything from buildings and cars to bullet proof jackets. Scientists put the material through its  paces in ballistic tests and found that a laminated version could even stop a projectile in its tracks. 

A new wonder material has been created from a surprisingly traditional source. Super wood is as robust as steel and six times lighter. Scientists put the material through its paces in ballistic tests and found that a specially laminated version can stop a projectile in its tracks

Engineers at the University of Maryland created their super dense wood by boiling blocks of regular wood in a water-based solution, containing the chemicals sodium hydroxide and sodium sulfite.

This process removed organic compounds in the wood that give its structure and rigidity, making it more pliable.shares

It is similar to the initial stages of treating wood to create paper. 

The team then pressed the softened wood between two metal plates, heated to 100°C (212°F), at 50 times the atmospheric pressure of the Earth. 

By doing so, all of the gaps between cells in the wood were squeezed together.

'Super wood' strong as steel can stop a bullet

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The pressure creates a chemical bond between the atoms that make up the wood's cellular structure.

It shrunk the size of the block to around one fifth of its original thickness, increasing its density by 300 per cent. 

Liangbing Hu, who led the research, said: 'This new way to treat wood makes it 12 times stronger than natural wood and ten times tougher.

'This could be a competitor to steel or even titanium alloys, it is so strong and durable. 

'It's also comparable to carbon fiber, but much less expensive. 

The team tested the new wood material and natural wood by shooting bullet-like projectiles at it. 

Engineers at the University of Maryland created their super wood by boiling blocks of regular wood in a water-based solution containing the chemicals sodium hydroxide and sodium sulfite

This process removed organic compounds in the wood that give its structure and rigidity, making it more pliable. This image shows the treatment process used

The projectile blew straight through the natural wood, while a single layer of the treated wood slowed the projectile's progress.

A third laminated version, consisting of layers of five-layers of the densified wood, was penetrated by the projectile but stopped it from exiting.

Dr Hu's research team has explored the capacities of wood's natural nanotechnology in the past.

WHAT IS THE STRONGEST MAN-MADE MATERIAL?

For years, researchers have known that carbon, when arranged in a certain way, can be very strong.

Two man-made materials based on carbon, Graphene and Carbyne, are among the strongest in the world.

Carbyne is linear acetylenic carbon, or an infinitely long carbon chain.

Its existence was first proposed in 1885 by Adolf von Baeyer, who warned it would remain elusive due to extreme instability.

Carbyne is a one-dimensional form of carbon and is thought to be 40 times stiffer than diamond and twice as stiff as graphene, outperforming all other carbon materials in strength.

After eluding scientists for more than 50 years, a team of researchers found a way to not only synthesize carbyne, but to mass produce it, in April 2016.

Graphene, a single atomic layer of carbon atoms bound in a hexagonal network, was previously thought to be the strongest man-made substance.

It not only promises to revolutionize semiconductor, sensor, and display technology, but could also lead to breakthroughs in fundamental quantum physics research.

It is often depicted as an atomic-scale chicken wire made of carbon atoms and their bonds.

Learn all about Graphene and it's applications

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Scientists believe it could one day be used to make transparent conducting materials, biomedical sensors and even extremely light, yet strong, aircraft of the future.

Similar to another important nanomaterial - carbon nanotubes - graphene is incredibly strong - around 200 times stronger than structural steel.  

While notable for its thinness and unique electrical properties, it’s very difficult to create useful, three-dimensional materials out of graphene.

In January, 2017, a team of MIT researchers discovered that taking small flakes of graphene and fusing them following a mesh-like structure not only retains the material’s strength, but the graphene also remains porous. 

Based on experiments conducted on 3D printed models, they determined that this new material can be used to make objects 10 times stronger than steel, with only five per cent of its density. They have previously made a range of technologies out of nanocellulose related materials.

This has included super clear paper for replacing plastic, photonic paper for improving solar cell efficiency by 30 per cent and transparent wood for energy efficient buildings.

The full findings of the latest study were published in the journal Nature.

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The pressure creates a chemical bond between the atoms that make up the wood's cellular structure. It shrunk the size of the block to around one fifth of its original thickness, increasing its density by 300 per cent. This image shows the changes in the various wood samples

The team tested the new wood material and natural wood by shooting bullet-like projectiles at it. This image shows the results of those tests

The first X-45A Unmanned Combat Air Vehicle (UCAV) technology demonstrator completed its sixth flight on Dec. 19, 2002, raising its landing gear in flight for the first time. The X-45A flew for 40 minutes and reached an airspeed of 195 knots and an altitude of 7,500 feet.




Credits: NASA Photo / Jim Ross Flying ships invulnerable to super cavitating torpedos


The Joint Unmanned Combat Air Systems (J-UCAS) program was a joint DARPA/Air Force/Navy effort to demonstrate the technical feasibility, utility and value for a networked system of high performance, unmanned air vehicles to effectively and affordably prosecute 21st century combat missions, including

 suppression of enemy air defenses, surveillance, and precision strike within the emerging global command and control architecture. One of the aircraft systems evaluated was the Boeing X-45A, for which NASA Dryden provided technical expertise and support facilities.

The X-45A was the first of two UCAV demonstration versions to be used in advance of fielding operational systems.

Project Goals

The project's goal was to demonstrate that a highly autonomous aircraft could suppress enemy air defenses or serve in a strike role. Dryden's participation in the UCAV System Demonstration Program was to support the DARPA/Boeing team in the design, development, integration, and demonstration of the critical technologies, processes, and system attributes, leading to a UCAV Operational System. Initially, Dryden supported the program through the various stages of flight development, including autonomous flight of two aircraft on separate flight paths that later joined for formation flight.

The design of the flying aircraft carrier 

A Blended wing body (BWB or Hybrid Wing Body, like a fixed-wing aircraft having no clear dividing line between the wings and the main body of the craft. The form is composed of distinct wing and body structures, though the wings are smoothly blended into the body, unlike a flying wing which has no distinct fuselage

The Blended Wing Body (BWB) is being considered as the next generation commercial airliner.  The trend is towards larger aircraft that can carry more people, economically while reducing the number of operations from airports.  He noted that recent surveys have identified about 60% of the delays are due to the number of aircraft saturating the airspace, as anyone who has been delayed can attest, the ramps and runways of airports.  This movement of more people on fewer aircraft has been defined by NASA as “The Lure of Large Aircraft”.  There are a lot of other infrastructure problems that also need resolving like terminal congestion, parking facilities and, adequate loading gates. 
     There is a very competitive large aircraft market as illustrated by the AirBus decision to produce the A3XX that could carry about 650 people on two decks.  The intra-Asian market is another area that can utilize high density loading.  They are already doing it with Boeing Super 747s rigged for full economy seating to haul 550 people over the short distances between cities.  The trade off is less fuel, but it isn’t needed for the short runs.  This is going to be a problem for the Chinese in about 10 years as they become more affluent and want to travel throughout their country. 
     Another aspect of large aircraft design is the ability to adapt it to the all cargo market.  Al didn’t hasn’t really seen the full logic behind the idea yet, but NASA is pursuing it.  With used Boeing 747s available at relatively low prices, along with other smaller aircraft that are readily available, the market for a new large cargo hauler may not be as great as expected by NASA.  Another aspect of large aircraft design is the ability to adapt it to the all cargo market.  Al didn’t hasn’t really seen the full logic behind the idea yet, but NASA is pursuing it.  With used Boeing 747s available at relatively low prices, along with other smaller aircraft that are readily available, the market for a new large cargo hauler may not be as great as expected by NASA.  However, the military gets interested it design and helps defray some of the startup costs, then the picture for the commercial markets could change. 

For the cost of a LCS below the Navy can have a 400 mph aircraft carrier $ 440M

“This is the first ship of its size for the Navy to have water jets for propulsion,”. “It has some very large gas turbine engines — Rolls-Royce engines — the same as a (Boeing 777) plane.” This should be the engine for our flying ship.

At full throttle, those engines can force nearly 2 million gallons of water through its four water jets in a minute — enough to fill an Olympic-size swimming pool every 20 seconds.

The flying ship is a ground effect vehicle (GEV)  a vehicle that is designed to attain sustained flight over a level surface (usually over the sea), by making use of ground effect, the aerodynamic interaction between the wings and the surface. Among the best known are the Soviet ekranoplans, but names like wing-in-ground-effect (WIG), flarecraft, sea skimmer, or wing-in-surface-effect ship (WISE) are also used.

Carbon fibre planes: Lighter and stronger by design

Image copyrightAIRBUS

Image captionCould this be the kind of airliner we're flying in, by 2050?

Aerospace and Defence

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When it comes to airliners, weight is money. The heavier a plane is, the more fuel it takes to drive it through the air. The more fuel it takes, the more it costs.

The drive to increase fuel efficiency and improve the aerodynamic performance of new aircraft is leading designers to move away from using aluminium in airframes.

Instead today's latest planes like Boeing's 787 Dreamliner and Airbus's A350 rely on lightweight carbon fibre composites - woven mats of carbon which are embedded in plastic.

The key to a composite material like carbon fibre is that it is incredibly strong for its weight.

"You have carbon fibres mixed into a matrix," says Manchester University lecturer Aravind Vijayaraghavan.

"Normally the matrix is a type of plastic, which is not very strong, but if you mix in carbon fibre then it takes on the strength of carbon fibre and becomes strong."

In the UK, European aircraft manufacturer Airbus has been working with Britain's National Composites Centre into research and modelling of new industrial designs and materials.

'Mould all the parts together'

Image copyrightAIRBUS

Image captionCarbon fibre means wing tips can be near vertical, improving efficiency

One development of this research has been the trailing edges of the wing of Airbus's latest plane, the A350.

Colin Sirett, Head of research, Airbus UK

This is the part that extends back and down from the wing as a plane comes into land.

"This is a component that takes the full load of those forces as you're travelling through the air at about 250mph - and you can lift it yourself," says Colin Sirett, head of research for Airbus in the UK.

"We could get a sledgehammer and take it to this panel and the sledgehammer would actually bounce off," he told BBC World Service's Business Daily programme.

Composites mean that manufacturers can get a good surface finish on components to optimise their aerodynamic performance.

Using these kinds of materials is also opening up other potential savings. An A380 super-jumbo, for instance, has about six million parts - but in future this could be cut considerably.

"We will mould all the parts together at the same time, so our perception of what a single part is will change," says Mr Sirett.

With fewer components, manufacturing time also will shorten, saving money.

Image copyrightBOEING

Image captionSo far 1,030 Boeing 787 Dreamliners have already been ordered

Crucially for aircraft manufacturers, carbon fibre components are lighter than similar parts made of aluminium.

"If we can take a kilogramme of weight out, that's got a huge saving over the life of an aircraft," says Mr Sirett.

Each kilogramme cut means a saving of roughly $1m (£603,000) in costs over the lifetime of an aircraft, he calculates - and the use of such composites can reduce the weight of an aircraft by up to 20%.

Growing use of composites

Of course, since the mid-1970s civil airliners have had some carbon fibre in their airframes.

Currently, Boeing's latest plane, the 787 Dreamliner uses composites for half of its airframe including the fuselage and wing, while Airbus's A350 XWB has both its fuselage and wings made of carbon fibre.

While the use of carbon fibre has allowed the creation of sweeping wing tips, which can cut fuel consumption by up to 5%, both aircraft are still fairly conventionally shaped.

Yet, the great advantage of using carbon fibre as opposed to traditional metal is that it gives designers much more freedom when trying to juggle the conflicting demands of aerodynamic efficiency, fuel savings and reducing engine noise.

So, the airliners of the future are likely to be radically different.

Such shapes could include blended wing designs, where the fuselage and wings merge into each other - like some military aircraft today.

Future designs

Image copyrightAIRBUS

Image captionCarbon fibre airframes mean that aircraft can be very different in shape

Such a design could significantly improve a plane's lift-to-drag ratio - making it much more aerodynamically efficient, and also reduce its overall weight.

Airbus recently unveiled its own proposals for an airliner of the future - and it too moves away from the traditional narrow tube-like fuselage.

Instead, its 2050 concept plane has a fatter fuselage, which is curved and shaped to improve airflow and to provide more internal space.

Its wings are longer and slimmer to reduce drag and save on fuel.

The tail section is U-shaped, which acts as a shield, cutting down on engine noise.

The engines themselves will have become more reliable, so ground crew will need to access them less frequently for maintenance.

This means they can be partially embedded in the airframe to improve fuel consumption.

Futuristic concepts like this may never quite get off the drawing board, but elements of it are certain to be incorporated in all future aircraft designs, in large part due to the materials revolution which is rapidly changing all aspects of manufacturing

On using carbon fibre
One of the worst misconceptions of carbon fiber composites is the thought that a little bit of carbon will add a lot of strength. Not so.

When you engineer a laminate of any sort with materials of different strengths and stiffnesses, you need to take into account two stiffness factors: E = modulus of elasticity of the material (Young's Modulus), and I = moment of inertia of the laminate cross section. The bending and stress behavior depends on the product ExI. If two materials of vastly different stiffness are bonded together in a working structure, in this case say wood and carbon fiber, then an even match and complementary bending behavior will be when the ExI of the wood equals the ExI of the carbon. E of wood can be anywhere from 500,000 psi to 2,000,000 psi, depending on the species of wood. Carbon fiber, on the other hand, can have an E anywhere from about 7,000,000 psi to 14,000,000 psi--many times greater than wood. In a wood rudder, the I of the rudder cross-section can be relatively high because the primary determinant for I is the thickness of the section, raised to the third power. With only a strip of carbon fiber within the laminate, however, the width of the carbon tape is generally not enough and the thickness of the carbon is really, really thin; and while the tape's distance away from the center of the rudder section is important and adds to its I, usually the I for just a strip of carbon is not anywhere near enough to add sufficient strength and stiffness to the section. The I is really, really small.

So what I am trying to say is that if you are going to add carbon fiber to a rudder, you had better be prepared add a lot of carbon fiber over the whole skin in order to make a significant difference. Stress in the laminate is always going to build up faster in the stiffer material (the one with the higher E) and if you don't have enough material in there to handle the stress that it is going to attract, then you have a potential for a real failure.

This is exactly what happened to the carbon fiber and aluminum rudder stocks for so many sailboats in the 1979 Fastnet Race disaster. Aluminum rudder stocks were shaved down thinner a bit (to save weight) and reinforced with just a small amount of carbon on the outside. Not enough carbon was there, yet the carbon tried to assume the lion's share of the load because it was stiffer than the aluminum. The carbon fiber failed when it got over-stressed, and once the carbon failed, there wasn't enough aluminum section left to handle the loads, and so the aluminum failed.

Finally, one of the biggest follies I have seen over the years is when boat builders use narrow strips of carbon fiber tape laid up into the hulls of boats in a cage like pattern. They think that this carbon "cage" will add a lot of strength to the hull, making it very stiff, like an internal framework. Nothing could be further from the truth. Generally, there is not enough carbon in there to do anything at all, the builders are simply throwing away money. If you want to make a really strong carbon fiber hull, then you have to have whole layers of carbon fiber spread throughout the laminate, and on both sides of the core if there is a core.


The biggest kicker is to take the body of theairplane and morf it with the   wing, then you get a body that produces lift merging with the spanloader idea.  You can’t take it to the point of a true flying wing due to the added wing area at the outboard ends creating too much

drag.  So you end up with a blended wing body that looks like the one below.  The lift to drag ratio can be increased from something like the 747’s 17 to the a range in the mid 20’s for the BWB.  This savings in drag translates into substantial economic and environmental benefits.  This particular model would be expected to use 20-25% less fuel, require 10-15% less weight (or conversely allow for more paying payload) and result in 10-15% lower direct operating costs.   You can’t take it to the point of a true flying wing due to the added wing area at the outboard ends creating too muchdrag.  So you end up with a blended wing body that looks like the one below.  The lift to drag ratio can be increased from something like the 747’s 17 to the a range in the mid 20’s for the BWB.  This savings in drag translates into substantial economic and environmental benefits.  This particular model would be expected to use 20-25% less fuel, require 10-15% less weight (or conversely allow for more paying payload) and result in 10-15% lower direct operating costs. 
    This was all started by a design study in 1989 by Dr. Dennis Bushnell, Chief Scientist at NASA Langley.  He foresaw the need for a commercial aircraft that could carry 800 passengers over 7000nm and a speed of .85 Mach.  This was the result of that design study which was originally McDonnell Douglas’. 
     One of the more interesting facets of this design was the position of the engine inlets.  Since they are right down on the wing surface, they are ingesting the boundary layer so any airflow sucked into the engines can be ignored as drag.  This gives a huge increase in the L/D due to the decrease in drag.  There are also a lot of control surfaces on this version, however, the larger inner surface has been eliminated in follow-on designs.  As part of what Al was talking about earlier, notice the 290’ span that won’t fit into the current passenger terminal infrastructure.  This makes this configuration non-viable as a solution to the high density passenger carrying BWB. 
      Al then moved from the outside features to the inside layout of the airframe.  The diagram shows how thisapplies the spanloader concept by having the weight out where the lift was being produced.  The passenger compartment goes out into the wing structure area which is obviously different that a conventional fuselage.  Outside of the passenger area are the main fuel tanks which also run out into the wings, further moving weight out to the lifting areas.  This is entirely different than the point loads of the fuselage arrangement.  
     In an overlay comparison of the BWB to the 747, you can graphically see why there is a problem with this particular BWB design.  You can park 747s side-by-side at current passenger terminal gates, but the BWB’s 290’ span makes this impossible.  Both Boeing and McDonnell Douglas looked into folding the wings like aircraft carrier jets, but determined that the public would not like to fly on an airplane that looked broke.  Another idea was to caster the wheels so the aircraft could come into the gate area slightly sideways, but this means higher weight in the landing gears. 
     Staying on the inside, Al put up a slide of a full scale mockup of a section of the passenger compartment.  One of the first questions everyone asks is where are the windows.  In this design there are no real passenger windows, but each seat will have a multi-functional LCD screen on the seat in front of them.  A selector will allow the passenger to select from a number of views, including looking to the rear and straight down. 
    The other obvious thing in the pictures are the really heavy structural walls between the compartments.  Al now went on to answer Ralph Wilcox’s question about how hard is it to pressurize a square box versus a cylinder.  The heavy walls are one of the ways and due this extra weight they also cut into the ultimate potential gains Al talked about in the first part of his presentation.  However, he also commented that it is expected enough gains will be made on the aerodynamic side to offset the extra structural weight.  Gavin asked about putting a series of round section within the wing to carry the pressurization loads.  Al commented that this was looked at, but in the final analysis it was determined that weight wise it is better with the current design parameters.  He did note there are some fatigue questions that still need to be worked out before there is any commitment to building something like the BWB. 

     Al moved along to the direct operating cost analysis between a 747, a new conventional design like theAirbus 3XX, and the BWB at the year 2015.  As the condition of conducting amphibious operations is the conquest of the air and sea superiority in the landing area, assault ekranoplans do not require heavy armament. The need to lay down suppressive fire on the beaches can be satisfied by Multiple Launch Rocket System (MLRS). Given the likely volume of fire missions it is best to have on board 12 220mm rockets or 40 122mm rockets. With this equipment, the possible number of troops on board the ekranoplan of two to three hundred tonnes of displacement can be estimated at one company of infantry with standard weapons and equipment. 

The numbers all show the BWB makes gains in the areas of operating costs, fuel efficiency, gross weight and nitrous oxide emissions.  This last item is of great concern to NASA since they have been linked to the green house gases.  Here there was a 17% expected gain for the BWB predicated on the fact there are no major breakthroughs in engine design during this period.  Some of the gains will come from a combination of many little improvements over the entire airframe versus one or two major improvements. 
     Gavin ask Al whether or not the airlines would be behind these types of changes in aircraft design.  Al commented that in his opinion changes in the environmental laws will probably create the need for such aircraft to meet things like emission standards.  If airport and airspace congestion rules are changed, the aircraft will have to change and the airlines will go along because they will have too. 
     The next slide was a comparison of the benefits and challenges.  The benefits include: lower operating costs; lower production costs; reduced airport/airspace congestion; lower fares; reduced environmental impact and; improved safety.  Operating costs he had already covered.  Lower production costs come from not have as many tight bends so the manufacturing costs go down.  Although the number of aircraft at terminals won’t go down, they will be moving more passengers with each departure which will impact congestion by preventing its escalation.  It is felt this design concept is at least as safe, and possibly saver, than a convention design. 
     The challenges included:  structures and materials; aero-structural integration; aerodynamics; controls; propulsion-airframe integration; systems integration and; infrastructure.  Structures is back to the pressurization issues and the integration issue revolves around making the structure clean enough to work aerodynamically and achieve the savings potential. 
     Aerodynamics is a separate issue from the aerostructures.  Imagine that this design has an elliptical span load associated with it, so that is the minimum induced drag for this vehicle.  Then think about the lift coefficient that needs to be produced for this type of wing.  Since the span load is chord dependent the center body section with its wide chord had no problem meeting the requirements.  But as you move out towards the tips you reach a pinch point where the chord narrows sharply.  The problem is going to tip stalling due to the high taper ratio and the loading out there.  This is a problem for the aerodynamicist since the aircraft must takeoff and land.  This means you need to generate high lift coefficients, which puts you close to the stall, which is also close to the departure.  Of course the last thing you want is a passenger aircraft with bad departure characteristics, so how do you get the lift coefficients at the pinch point to avoid these problems or at least degrade elegantly so you don’t lose control of the airplane. 
      Ralph asked the question about boundary layer control at that point on the wing.  Al commented that it had been looked at and there was still a problem even using vortex generators.  Boeing went to slats on the outboard section since this would generate a lot of lift on this portion of the wing.  The disadvantage of this system is that slots and slats have really bad hysterisous effects, so once stalled it might be hard to get back.  NASA is still looking into this area. 
     On systems integration, Al noted that this area is becoming more and more complicated.  This is the digital fly-by-wire systems so you can control the way in which the aircraft reacts to the control inputs.  This particular design has a nose slice just before reaching the stall, so some method is needed prevent in inadvertent departure.  The digital controls with its accelerometers and other sensors feeding back information, the control surfaces in the affected area can be deployed upward to decrease the span loading and move it inboard.  This will prevent the airplane from departing, but it is so sensitive that any external changes can have major effects on the departure characteristics. 
     Gavin asked a question about what types of construction techniques would be used for this aircraft.  Al said it was planned to be built by bending tin and used the 747 as an example.  If you look at the outer wing panels on the 747 and compare them to the same panels on the BWB you find they are very similar.  Since the BWB was originally a McDonnell Douglas design, the outer wing sections were based on the DC-12 which was never produced because of the buyout by Boeing.  This then became a good starting point so the center body construction problems became the focal point of further development. 
     Al moved on to the really big issues of structure and aero-structural integration; non-cylindrical pressure vessel.  How do you pressurize something that doesn’t look like a tube or a sphere.  Initial thoughts were to use conventional metallic structures, but more recently thoughts have been turning towards composites like graphite stitched epoxy resins.  They are questioning whether this would help with the pressure structure problems and perhaps also save some weight.  For protection:
For Flying Aircraft Carriers, the best defensive weapon is a 150kw laser

US military will use SUPER LASERS with 150kW of power to knock out enemy missiles by 2020

• A 60 kW laser weapon will soon be installed on a US Army truck

• But experts believe that weapons with 150 kW power could be used by 2020
• Such a laser could knock out a missile sideways on, where it is most vulnerable 

While laser weapons have been a staple in science fiction films for decades, the US military is inching closer to making these a reality. 

Lockheed Martin has announced a 60 kW laser weapon that soon will be installed on an Army truck for testing against mortars and small drones. 

And experts believe that lasers even more powerful than this could be widely used as soon as 2020. 

+5

While laser weapons have been a staple in science fiction films for decades, the US military is inching closer to making these a reality 

LOCKHEED'S LASER 

Lockheed Martin's laser is 60-kilowatt, and invisible to the naked eye. 

By focusing the beam onto a target, the technology rapidly heats the inside of an incoming mortar round, causing it to explode mid-air. 

This allows it to take out a drone from a distance of about 500 metres.

The laser weapon can also pierce the outer skin of a drone, taking out key circuits and making it crash. Lockheed Martin's 60-kilowatt laser weapon can take out a drone from a distance of about 500 metres, by keeping its beam locked onto the target for a few seconds, according to Jim Murdoch, an international business development director at Lockheed.

But unlike in the movies, the laser beam is invisible to the naked eye.

By focusing the beam onto a target, the technology rapidly heats the inside of an incoming mortar round, causing it to explode mid-air. 

This is an impressive feat, considering the round is moving at hundreds of miles per hour.

The laser weapon can also pierce the outer skin of a drone, taking out key circuits and making it crash.

For the moment, the lasers being tested are all of about this same power.

But Mark Gunzinger, a senior fellow at the Centre for Strategic and Budgetary Assessments, sees that relatively small output increasing rapidly.

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The US Navy has since 2014 been testing a 30-kilowatt laser on one of its warships, the USS Ponce (pictured)

WHAT COULD A LASER BE USED FOR?

While the US Navy has not specificed whether the laser could be used for any specific threats, director energy weapons could have a range of used.

This includes:

- Destroying threatening drones

- Shooting down incoming air-to-air missiles

- Hitting targets on the ground much like regular aircraft gun Within just a few years, he expects far more powerful prototypes of more than 150 kilowatts.

Such a laser could knock out a missile sideways on, where it is most vulnerable.

He said special operations forces want to test such a system by 2020 on an AC-130 gunship that specializes in ground support for troops.

And within six to eight years, US forces could begin using laser systems of more than 300 kilowatts, he added.

That degree of power could knock out an incoming missile head-on.

The US military is also weighing the possibility of mounting lasers on drones flying at very high altitudes, making them capable of shooting down ballistic missiles shortly after launch.

+5

Within just a few years, experts believe that far more powerful prototypes of more than 150 kilowatts will be used. Such a laser could knock out a missile sideways on, where it is most vulnerable (artist's impression)

Another bonus for the military from lasers is the promise of seemingly unending and cheap firepower.

Unlike conventional canons that need shells, laser canons are limited only by the amount of electricity that can be generated.

Mr Gunzinger deems lasers as especially promising on warplanes, which could potentially get an unlimited reservoir of firepower to defend against adversaries' missiles.

'An aircraft doesn't have to return to base to upload more weapons. It could refuel and continue to operate with its nearly unlimited magazine,' he said.

+5

Unlike conventional canons that need shells, laser canons are limited only by the amount of electricity that can be generated 

But before laser technology can be integrated into combat planes, it must first be shrunk in size.

Currently engineers are running into physical limitations on how much portable power can be produced, and ways of cooling the technology.

Lockheed Martin wants to increase the power of its truck-mounted laser.

Mr Murdoch said: 'For a vehicle like this, there will be some engineering limits. We will run out of space...that's the kind of challenge we are working.'

By focusing the beam onto a target, the technology rapidly heats the inside of an incoming mortar round, causing it to explode mid-air (artist's impression)

But industry reps and military officials say there's only one thing stopping lasers from garnering widespread operational use: government funding.

Lawmakers recalled a lengthy program that cost more than $5 billion (£4 billion) in which a Boeing 747 was retrofitted to carry a laser gun supposedly capable of shooting down enemy missiles.

The programme was scrapped in 2012 over concerns it could never be operationally viable.

The laser beam used in that technology was generated by chemicals so was not strong enough to take out a missile.

     There is another issue with joints between the various panels.  One of the things NASA does with their test aircraft is go through a ground vibration test.  Hopefully this predicts what the structural modes are in the wing.  The is a mass suspended by a fairly rigid beam structure which will vibrate at a particular frequency and a guess is made as to what it will be based on the existing structure. 
     With metal airframes there is an I-beam with a plate on the top, the skin, that is riveted in.  It turns out that due to the factors of give, flex and friction the actual frequency actually, when tested, comes out lower than the prediction.  This goes back to the fly-by-wire system where the pilot can make a jerk input to the stick which would give an almost perfect square wave input to the system.  The system looks at it as a change to the angle of attack.  In most airplanes the change would occur gracefully with some overshoot and then stabilize out, which is the short period frequency.  If this frequency is the same frequency as the structural wing bending the aircraft will catastrophically fail.  The pilot can’t be told not to make these types of control inputs, especially if they are fighting an aircraft in turbulence while landing.  
     Now we bring in the composite structure.  Some composites joints are glued together and other are not, so in some cases there are butt joints where the load transfers are harder to calculate.  In tension and compression there is pretty good data, but not in the bending.  Apparently the joints don’t handle the stresses that same way in each direction so this makes the calculation much more difficult.  At this point in time there just isn’t a lot of experience on how to handle these types of joints on airplanes.  This is due to the load having to transfer from one skin, through the flange or other connecting structure, to the other skin.  Since the cloth fibers are not running continuously along the known stress line, the calculations become much more complex. 
     Another major issue that will need to be worked in the future, but is not a top priority at this point, is the outer surface “bulging” that will occur as the aircraft is pressurized.  These bulges will form in-between each of the main structural bulkheads forming the passenger compartments.  Obviously this will deform the elegant cruise airfoil shape that is being planned, so it has to be taken into consideration in the design.  When doing this with composites it becomes even more difficult due to the lack of experience in this area. 
     Another set of challenges that up early on were just the aerodynamics.  This is still looking at an 800 passenger, big BWB aircraft with three engines sucking in air over the upper surfaces boundary layer.  After running computation fluid dynamics to predict what the flow would be, they found two areas of reverse flow.  One was where the lift coefficient was very high, right at the sharp break in the trailing edge and right over the control surfaces.  The other problem is putting people inside the airfoil which now has to be thicker than people are tall.  This gives you a very thick, transonic airfoil which sets up new challenges to overcome the various shock waves and resulting wave drag.  All these are bad things that need to be addressed and viable solutions found before continuing.        Ride quality is another issue that needs to be looked at.  When you put all the control surfaces in close together in one location fore and aft, the whole aircraft is affected by turbulence at one time.  So given the same level of technology in control feedback systems as currently used on conventional aircraft with control surfaces spread out over the wing and tail surfaces, the ride quality of the BWB, or a flying wing, will be worse.  New feedback technologies need to be developed for the improving ride quality without letting things get so sloppy that the pilot can’t control the airplane.  
      Along with the digital fly-by-wire comes the all electric subsystems; everything is electronic onboard the aircraft.  This is a very common in the military in aircraft like the Air Force’s F-16, but is just now starting to become more prevalent in commercial aircraft.  Doug Fronius asked if this meant no hydraulics and Al commented that there were still hydraulic actuators being controlled electrically at the site of the control surface.  Doug noted that the next generation of military aircraft coming along will truly be all-electric with no hydraulic subsystems.  Although there are some supporting subsystems on commercial aircraft at the present time, both Doug and Al indicated all-electric main systems were probably a long way off. 
      Dominique Viellard asked about the thickness of the boundary layer.  Al said he wasn’t sure about the numbers, but did estimate it could be a couple of feet thick at the rear of the centerbody section of the wing.  The chord at this point is close to 160’, so Al wouldn’t be surprised if the it reached these larger thicknesses. 
 Ralph Wilcox asked about what the wing loading would be for this type of wing.  Al commented that when you go to a flying wing you need to bring the numbers back down from what you would have for a conventional aircraft.  So instead of having the 105-120 numbers for things like the Boeing 7X7 series, you need something like 95-105.  This is easier to do on the BWB since you have so much more wing area. 
      Gavin Slater asked about the problems associated with boundary layer ingestion (BLI) on the three engines at the back of the aircraft.  Engines don’t like to see a lot of distortion at the compressor face and, this will become even worse at high angles of attack.  The boundary layer will get much thicker and it presents many problems in designing ducts or making changes to the engines themselves.  (ed. – This problem has led to a different engine configuration as shown below.  The engines have been moved up on pylons to get them out of the boundary layer flow at all times.) 
      Al moved on to the infrastructure problems noted earlier.  The ICAO wants to stay with the 80m (262 ft.) wingspan separation between terminal gates, so this becomes an intractable problem.  The 800 passenger version was also a double-decker which presented another set of problems with the existing gate structures.  The two decks also raised concerns over passenger safety in a crash situation where the upper deck could collapse onto the lower one.  The last issue was how to you handle 800 passengers for several airplanes at a time in terminals not designed to handle that volume of humanity. 
     SO, this all had the engineers at Langley pulling their hair out.  The upper left segment of the slide shows a 1% spin tunnel model at Langley.  They tried a couple of different models and the one that is going to be flight tested showed high yaw rates.  There also appears to be an auto-rotation tumble mode that was observed in the tunnel tests.  The lower left segment shows a model in the acoustics chamber being tested of radiation’s from things like the radio antennas.  The other pictures on the slide show some of the various models that were put through further tunnel testing leading up to changes in the configuration that will be flight tested. 
      Al then laid some background on the changes that were being made for the upcoming flight test model.  The top picture below are of the models Ilan Kroo and his graduate students at Stanford University built and flew as proof of concept vehicles.  The top one is a 6’ R/C model flown with fairly stable static margins.  There were two versions, one with gas power for longer flights and one with electric power (cleaner and quieter).  The lower picture below is the 17’ version with a true closed loop control system using a MacIntosh laptop computer as the processor for this system.  This was a twin engine, gas powered model with multiple control surfaces, each one controlled by an electric actuator designed and built by the students.  Ilan also designed the internal instrumentation systems. 
      The large number of control surfaces presented their own unique troubles.  Since any one control deflecting upward will cause the aircraft pitch up the question became one of how best to control the mixture of movements.  They had to determine whether there were any pitfalls like airflow separation as the controls moved in differing amounts.  Some of these questions are being answered through wind tunnel tests. 
      Andy asked Al what caused the phenomenon on the model where the control surfaces appeared to be flopping around during ground taxi.  Al indicated the controls were responding to the inputs from onboard sensors being activated by bumps in the taxiway.  Due to the low airspeed associated with taxiing, the control deflections to correct the sensed conditions were large and therefore drove the surfaces to their stops.  The electric actuators are very fast, so it appears the surfaces are just really loose on the hinges.  Al noted this occurs on current fly-by-wire aircraft in the military as they taxi, you just have to look closely to see it. 
      As Al continued, he noted one of the big questions revolves around something they call “behavior quantification”; how does the aircraft behave, what does it do.  They have problems with stall, the aeroelastic properties cause dive problems during the pull out,  and a mach buffet with an “ugly” tuck.  Then there is the issue of engine out performance since it doesn’t have real strong directional stability.  If you loose an engine, what is the Vmca really going to be?  The last issue is stability margin in terms of pitch, lateral and overall directional control. 
      Up to this point everything that he had been talking about revolved around the 800 passenger version that was studied under a NASA contract that ended in 1996.  At that time the Douglas division of McDonnell/Douglas picked up the study and continue it on their own money.  These studies resulted in design you see below, which was frozen sometime late last year.  The Douglas division of Boeing then continued the project and have further refined the design, which no longer looks like this drawing.  However, this is the design version NASA is continuing with for wind tunnel testing and construction of the remotely piloted vehicle (RPV).  It is 14.2% scale with a 35’ wing span.  The flight control systems are being designed at the Dryden facility, but the actual construction and installation of the boxes is being done at Langley.  Boeing is also providing engineering support for the vehicle.  
      One of the first things you notice on this design is the engines having been raised out of the boundary layer flow.  This was the fastest and easiest way to solve the inlet and compressor problems trying to deal with the turbulent flow off the rear of the wing, especially in high angle of attack flight.  Since this was going to be one of the hardest problems to solve and may not have been economically feasible, the simpler approach was taken.  
      Although hard to see in the drawing, the control surfaces are spread out differently.  There are now 16 control surfaces instead of 22, but it still have the split elevons in the last four outboard elevons, with the outermost two being ganged together.  It is all electric with no hydraulics on board, using control actuators taken from an air-launched munitions program.  These actuators are designed to work for 90 seconds, yet the test vehicle is being designed to last for 100 hours, so there was another problem than needed to be worked out.  It turned out that the actuators were way over designed for the munitions application and probably would last much longer in the less demanding environment of the BWB.  The model was also being built in such a manner that the actuators could be easily removed if they showed signs of failure. 
      The next problem they had to overcome is which digital controller would drive which control surfaces.  To maintain a minimum level of redundancy, each controller must drive actuators at different parts of the wing so the failure of one controller will not bring the aircraft down.  A little later there was a discussion between Al and Doug about the software NASA is using so the controllers know which one takes the lead and how the entire system determines when the lead controller is actually have a problem and needs to be relieved by a secondary unit.  This got a little deep on the technology side, so not much more will be covered here. 
      Power will be provided by three Williams turbojet engines from target drones that are designed to operate for about 10 hours.  The same issues came up here as with the actuators, plus there was no low idle setting (below 90 lbs.) on the fuel control (the Navy didn’t need low idle for in-flight launch so it was not designed in by Williams).  The spool up time was also not acceptable since the engine would take 33 seconds from idle to the full thrust of 240 lbs.  After long discussion with Williams and a lot of money, NASA got their supply of engines with a 35 lb. idle setting and a much faster response time from idle to full power.  Since the test vehicle only needs about 190-200 lbs. per engine, a detent was placed on the pilot’s throttle console to limit thrust at 200 lbs.  This will make the engines last well beyond the 10 hours.  The pilot will have the ability to remove the detent in the event of an engine failure and more power is needed from the remaining engines. 
      The wing does have slats on the leading edge, however, they do not have actuators so are locked in a fixed position depending on the type of test to be conducted.  The original plan called for a ballistic recover chute to save the model, but that has been removed and replaced by triple redundancy in the control software (remember spreading out the control surfaces between controllers) and dual redundancy on hardware.  The various antennas will be integrated into the structure to try and keep the surface as clean as possible.  There will be a spin recovery chute since plans call for spin testing of this model, along with attempts to make it tumble. 
      Al mentioned that the weights shown in the slide were dynamically scaled to the commercial, full size version.  He gave the example of scaling something down by one half, which results in a piece of hardware that has one quarter of the area, one eighth the volume and one eighth the mass (dynamic scaling).  The other scaling factor is moment of inertia.  NASA has a very specific set of weights, moments of inertia, area and size targets for this project.  The 2,700 lbs. represents the scaled maximum takeoff weight of the full size aircraft.  On the other hand, the 2,300 lbs. minimum (empty) weight is well above the truly scaled 1,300 lbs.  This is due to the fact you can’t always economically scale down things like actuators and other types of hardware, computer systems and other instrumentation.  They are not satisfied with the high weight and are trying to get it down below 2,000 lbs., but they are not sure this will happen.  The construction is all carbon fiber and Al gave as an example of weight savings the winglet’s vertical surfaces.  These have a design weight of 7 oz. including all hinges, horns, ribs, etc., and will have to withstand a max speed of 140 knots.  Based on what they know now it doesn’t look like they will make that weight, but at least it will be the minimum they can make it. 
      One other thing he wanted to cover on this slide was the relationship between the 14.2% scaling factor and the 35’ wing span.  If you do the math they don’t come out to the 289’ of the model he was talking about at the beginning the presentation.  That’s because this model is for the smaller, 450 passenger, single-deck version that Boeing is working towards.  This is still bigger than a current B-747, so many of the earlier noted problems regarding infrastructure still apply. 
      The next slide shows the molds being built at the Langley facility.  The pictures were taken in June and work has now progressed to the point of laying cloth into the molds.  However, all of the structural analysis has not be completed so they are not sure how many layers of carbon fiber will be needed.  So the engineers are in the catch-up mode trying to get the numbers put together so the technicians can get back to building.  The 3% wind tunnel model was nearing completion and it was expected it would go to the tunnel in late September.  This model is correct configuration for the skins that are waiting for the final numbers. 
      The lower right portion of the slide shows the general layout of the test model with fuel tanks and elevons located in and one the center section.  The wings will be separate which is mainly so the model can be shipped more easily with the plan being to use a large motorhome that doesn’t have any interior (just a big box on wheels).  Alternate shipping plans include using Air Force C-17 training missions and, as a last resort, paying to ship it on a Super Guppy. 
      What NASA is doing here is looking at the flight characteristics of the BWB class of vehicles.  Although the test model doesn’t reflect the latest developments in design changes (as a result of freezing the design for the models purposes), all the test data will be extrapolated to the latest versions using data obtained over the life of the project.  
       The next slide was a listing of the goals for the ELP (Envelop Limits Program) research, which is where all this is leading too.  Things like what happens when you stall it, spin it, tumble it and can it be recovered aerodynamically.  Can these modes be prevented aerodynamically using the controls surfaces on the aircraft and, if you can’t what will it take in terms of the system software, etc. 
       At this point Al took a few minutes to explain a little more about dynamic scaling.  If everything goes as planned, the model’s scaling will exactly duplicate the aerodynamic forces are work in all phases of flight.  So the numbers they get from a wing tip’s helix angle as it falls off in a stall will be exactly what the full scale aircraft would see under the same angles of attack.  There are a couple of gotcha’s here, one being mach number since the model will be nowhere near that of the full size aircraft.  For the low speed end this shouldn’t be too much of a problem, but they can’t do anything about the differences in Reynolds numbers between the vehicles.  

This ship will be made of  titanium foam wchich has more strength for its weight than steel—Ti offers a 40% weight savings compared to steel—lightweight designs can be achieved that offer increased payload capacity, reduced fuel consumption and reduced carbon emissions.  It has a low magnetic signature, which means you can reduce heavy and power-consuming degaussing coils to protect against magnetic influence mines.  It has temperature resistance, so it’s safer for structures like gas turbine exhaust systems.  And Ti is virtually corrosion-free in seawater, so it can be cost effective for sea water piping systems such as cooling water and firemain.

However, more research is needed to develop high-productivity Ti welding processes for ship construction.  Although well established, the existing titanium welding processes are too slow for ship hull construction which typically requires miles of welds, according to Dr. Pingsha Dong, a professor at University of New Orleans School of Naval Architecture and Marine Engineering, and director of UNO’s Welded Structures Laboratory.  Through the UNO investigation, advanced metal inert gas (MIG) welding and friction stir welding showed their potential.

Chris Conrardy, chief technology officer at the Edison Welding Institute (EWI), says there are different techniques for welding titanium, including gas tungsten arc welding, electron beam welding, high-power laser welding, friction stir and hybrids of the different methods. "The optimum approach depends on the structure’s configuration, joint design, performance requirements, and economic considerations."  

But in each case, quality control is paramount, and inert gas shielding is required to avoid contamination.  "Avoidance of contamination is a primary concern with all titanium fusion welding processes," Conrardy says.

“Titanium is highly reactive at elevated temperatures and requires shielding of the molten metal during welding and cooling,” says Jennifer Wolk, a materials engineer with Naval Surface Warfare Center (NSWC), Carderock Division specializing in welding and friction stir welding of non-ferrous materials.

“Most steel ships are scrapped because of corrosion of the hull, not problems with the machinery,” says Rob Moore at Textron Marine & Land Systems (TM&LS).  “TOC is reduced by using a titanium hull.”

Aerospace grade titanium used in aircraft is about nine times more expensive than steel.  But industry experts predict that  “fit-for-purpose”  ship hull or marine grades of titanium, as proposed by UNO, could be made less costly—perhaps only three times as expensive as steel —by changing the processing and finishing requirements.   When weighed against its positive attributes, titanium may become even more cost effective.

Moore says Ti production is energy dependent and the cost of energy is not going to go down.  But, he says, marine grade Ti will likely cost much less than commercially available aerospace grade Ti.

Marine specific Ti grades have been developed and used for some high strength naval applications, such as piping, but not for general structural applications.  The cost of marine grade Ti would depend on the end use and properties needed for the application.

Colen Kennell of the Center for Innovation in Ship Design at NSWC Carderock says Ti offers a potentially ship-scale cost effective alternative to steel structures.  “For faster ships, lightweight hulls are a critical enabling technology."

As a further benefit, when a vessel reaches the end of its service life, its scrap value is much higher than a steel ship.

“Old ships are a problem,” says Kennell.  “Ti scrap retains substantial value even at the end of a 30 or 40 –plus year ship life.”

There are other alternatives to steel, such as aluminum and composites for ship structures.  “If you want an all-composite ship, then you would need an all-composite shipyard.  But Ti could be introduced in a steel yard,” says Kennell.

Wolk adds that Ti fabrication currently exists in shipyards, but does require strict controls for fabrication.

There is also the possibility that building ships from titanium would create a demand that would drive the cost up for the metal.  There is precedent, when there was an unexpected demand for Ti when Callaway introduced the Big Bertha golf club at about the same time that Boeing announced the start of construction of a new airplane.  A spike in the titanium market could also disrupt the aerospace sector.  

But suppliers at the conference said that even if the Navy decided to build three or four Ti ships a year, US Titanium capacity is not a constraint.  The US has sufficient projected capacity looking at current demand signals, and steps can be taken to mitigate demand spikes.

Such a fabrication facility would require a significant investment, Kennel says, and without additional demand it might be unsustainable.  “But there aren’t any show-stopper industrial or management issues.”

Raymond M. Walker of Keystone Synergistic Enterprises in Port St. Lucie, Fla., says the workshop demonstrated that there are no engineering barriers or obstacles that prevent design or construction of a titanium naval ship.  “Challenges, yes; but no barriers.”

Walker, an expert in welding and joining of titanium and vessel fabrication, says it was valuable to have representation from many of the key players in the effort to manufacture with titanium: the titanium material providers, titanium processing and joining experts, ship designers, ship fabricators, as well as commercial interests.  “It was helpful to get a consensus from this group as to the realities and methods needed for fabricating a titanium vessel.”

Vessel life, fuel efficiency, reduced maintenance, and increased range/payload will drive the argument, Walker says.  “No new technologies are required, only adaptation of existing titanium practices (primarily from aerospace) to the specifics of vessel design and fabrication.”

“The Navy is challenging industry to produce an affordable solution and we all have to take that as an action item to deliver this package as soon as we can back up the numbers and corresponding data,” says Booty Cancienne, production superintendent for Textron Marine and Land Systems (TM&LS) in Slidell, La.

Cancienne is production supervisor for the TM&LS shipyard with four decades of experience.  He’s worked at TM&LS for 35 years, and five more at other yards.  He is responsible for all marine construction at TM&LS, including development of all processes, materials and metals used, training of employees and schedule and cost for all programs.   He has overseen the construction—and later the refurbishment—of dozens of Navy LCACs (landing craft air cushion).  In his job, he makes recommendations for engineering changes to reduce cost and to improve construction fabrication.   At the workshop, when it came to welding, his was the voice of experience.

Most recently, he has been involved in the TM&LS proposal for the T-Craft innovative naval prototype being investigated by ONR.  TMLS has fabricated a T-Craft side-hull section of aluminum, and will build the same structure from titanium to provide comparison data. 

Cancienne says a titanium hull is possible.  “We in industry must make the fear of high cost go away.  We have to develop some processes to reduce cost and turn everyone’s attention to the customers’ needs and how to meet commercial and Navy requirements.”

The business case 

While a number advances have been made in processing, design, and fabrication, the hurdles that the Navy faces regarding the use of titanium are the same hurdles that we faced 10 to 20 years ago.  “It all boils down to material and fabrication costs.  Until the program offices can overlook the acquisition costs associated with using titanium components and see that the long term benefits outweigh the acquisition costs, there will still be hurdles to using titanium,” says Kim Tran, a materials engineer at NSWC Carderock where she is the non-ferrous welding lead.

Tran says an all titanium ship is not realistic until industry can reduce the cost of material to a more affordable price.  “In the past, $4 /lb was the target price for the DARPA low cost titanium initiatives,” she says.  “With regard to titanium applications, if industry can reduce the current material prices, there may be more opportunities for titanium components on Navy ships.  Reduced fabrication costs are also important.  Traditional processes for fabricating titanium components are expensive because of the cleanliness requirements for the handling of titanium and complete shielding requirements for arc welding.  Technological advances to reduce fabrication costs yet still enable the fabrication (casting, welding, forging) of quality products that meet design and material properties requirements will also enable more opportunities for titanium applications on Navy ships.”

To reduce fabrication costs, Tran says more research is needed to reduce the current arc welding shielding requirements.  “Complete inert shielding during arc welding is the biggest cost driver associated with welding titanium.  In the past, NSWCCD has investigated flux cored arc welding wire and using a flux paste to eliminate the requirement for backside shielding.  These were limited studies that should be revisited.  Higher productivity welding techniques such as gas metal arc welding (GMAW) and hot wire gas tungsten arc welding (GTAW) should also be researched.  GTAW is the primary welding process for welding titanium because it is much cleaner; however it is also a low deposition process requiring more weld passes to complete a joint than GMAW.  Using GTAW results in increased fabrication time and cost.”  

Walker agrees that more study is need to make the business case for a titanium ship, “A credible business case study would be a significant accomplishment to solidify the benefits of titanium vessel fabrication and drive titanium into consideration for new vessel designs.” 

As an example, Walker points to the aerospace industry, which he says understands lifecycle ownership cost and has justified gas turbine engine investments to achieve thrust and fuel efficiency improvements.  “Increased thrust relates to increased payload or passenger capacity.  Fuel efficiency benefits rapidly multiply into very large life-cycle cost savings for both military and commercial aircraft.  A similar case exists for a titanium vessel in terms of maintenance, corrosion management, reduced painting and coating requirements, lower vessel weight, fewer shipyard visits, longer service life, and so on.”  

Existing shipyards view titanium as a specialized process that is a cost burden over the state of fabrication for steel, Walker says.  “A business case could also be supported by the fact that titanium vessel fabrication should be performed in an aggressively lean environment of a ‘small shipyard of the future,’ where material handling, welding practices and environments, material flow, and modular construction methods are optimized to titanium to drive down costs and are biased to light metal fabrication (aluminum and titanium). “ 

Cancienne says the Navy will save a tremendous amount of money with titanium ships just in upkeep of the hulls alone.  It’s an issue of cost versus longevity.

“This is the bottom line,” he says.  “If a hull lasts 50% longer, say 60 years instead of 40, you get the same service life as three conventional hulls for price of two titanium ships.  Upgrades in electronics, machinery and propulsion are a lot cheaper than building a new ship.”

“Titanium is a common metal, it is easily formable, very weldable, has excellent strength, and is corrosion resistant,” Walker says.  “A titanium vessel is absolutely possible.  There are plenty of pockets of titanium design and fabrication expertise in industry that are producing titanium structures every day.  Very little of this expertise resides in traditional shipyards.”

BoldMar, Inc. plans to build mega-yachts and commercial vessels at NASA once fabricated shuttle fuel tanks, and the Aries capsule is being built today using state-of-the-art welding techniques.  The Michoud facility is also home to the National Center for Advanced Manufacturing, which is leading the way in new materials and welding methods, including friction-stir welding. Friction-stir welding welds mated metal pieces without melting them, causes less damage to the materials, and can be automated with precision results.

BoldMar has embraced friction-stir welding and is able to use one of NCAM’s three $20 million friction stir welding machines.  “This process will reduce fabrication time by 40% and eliminate a majority of the harmful flash and fumes associated with fusion welding for a cleaner work environment,” Bolderson says.

More importantly, friction stir welding could be very advantageous over fusion welding processes for joining thin titanium plates and structural forms from both weld quality and distortion control point of view.

Bold-Mar production of vessels is primarily of aluminum, but has its sights on building vessels from titanium, including offshore patrol and service vessels.

Moving forward with titanium may be what America’s shipbuilding industry needs, Bolderson says.  “America today is an uncompetitive, third-rate shipbuilding nation, unlike what we were 70 years ago.  Building in titanium will leap-frog us ahead of other nations in utilization of Ti as a superior material for shipbuilding; and using automated production technologies will help re-establish America as a competitive and premier shipbuilding nation.”

      For those of you who are concerned with how your government spends its money, Al noted one of the things they are trying to do keep this program under cost control and set an example for future projects.  It is a partnership venture between the design engineers at Langley, the flight research group at Dryden and Boeing to do everything right the first time around.  
      At this point Al went into his summary.  The BWB offers potential for substantial economical and environmental benefits.  The BWB is a high-risk, high-payoff conceptual platform and it is felt NASA’s involvement is appropriate.  NASA is now committed to investigating the low-speed stability and control attributes of this confirguration.

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