On Sunday, August 21, 2016 at 6:21:06 PM UTC+12, William Mook wrote:
On Sunday, August 21, 2016 at 6:37:07 AM UTC+12, Robert Clark wrote:
American Journal of Nanomaterials
Vol. 4, No. 2, 2016, pp 39-43. doi: 10.12691/ajn-4-2-2 | Research Article
From Nanoscale to Macroscale: Applications of Nanotechnology to Production
of Bulk Ultra-Strong Materials.
Robert Clark
Department of Mathematics, Widener University, Chester, United States
http://pubs.sciepub.com/ajn/4/2/2/index.html
Next stop: the space elevator.
Bob Clark
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Finally, nanotechnology can now fulfill its potential to revolutionize
21st-century technology, from the space elevator, to private, orbital
launchers, to 'flying cars'.
This crowdfunding campaign is to prove it:
Nanotech: from air to space.
https://www.indiegogo.com/projects/n...ce/x/13319568/
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Before space elevator, look for very lightweight, very capable high pressure tanks and rocket engine casings.
http://www.tms.org/pubs/journals/jom...rado-9607.html
http://www.grantadesign.com/download...-RW-UOC-EN.pdf
http://www.pnylab.com/pny/papers/youngs/youngs.pdf
Young's modulus of materials that exhibit 1200 GPa at 1.4 g/cc makes it 12x stronger than an epoxy matrix at about the same density!
This will allow the weight of an aircraft structure to fall from 47% of a plane's weight to 4% of a plane's weight!
In aerospace practical nanotube structures, will allow a high pressure tank to go from 20 atm (300 psi) to 200 atm (3,000 psi) and permit the elimination of turbomachinery altogether, whilst improving thrust to weight from 120 to 1 to 1,500 to 1 in conventionally scaled engines operating at 200 atm, with overall structure fractions in the 1% range even with low density cryogenic fuels. Performance goes even higher with MEMS scale engines, since engine thrust scales with area and engine weight scales with volume - 12,000 to 1 for MEMS scale engine arrays!
http://www.ese.iitb.ac.in/~pratibha/...ey,%202009.pdf
Very high pressure allows the storage of hydrogen as a supercritical slush. Hybrid storage of hydrogen, where high pressure is applied to store hydrogen as slush or a supercritical fluid. By cooling pure hydrogen below the freezing point at 259 -C, a mixture of solid and liquid hydrogen, called slush, can be produced. This provides higher energy densities if high pressure may be maintained at low mass. Nanotubes provides a means to achieve this.
At 200 bar and 20 K a density of 90 kg/m3 is achieved in liquid hydrogen. Figure 1.21 page 32 in the reference above. This is 30% greater than its density at boiling point.
LOX has a density at its boiling point of 1,141 kg/m3. A similar increase is possible with LOX at 200 bar at 52 K - increasing density to 1,483 kg/m3.
With a 6 to 1 oxidizer to fuel ratio, at 200 bar combustion chamber pressure, specific impulse of 495 seconds 4.85 km/sec exhaust speed - is achieved. With a 2% structure fraction a SSTO vehicle with 85% propellant fraction is possible and a 13% payload fraction! This is about the same as today's airliner in terms of payload! With a 461.8 kg/m3 average propellant density at this oxidiser fuel ratio
A Boeing 737-300 has a payload of 14.25 metric tons. So, a 109.6 metric tons take off weight for the aforementioned SSTO. 2.20 tonne structure built out of nanotube fibres as described. 93,160 kg of propellant occupying 201.7 cubic meters. A 7.3 meter (23.9 ft) diameter sphere, in the centre of a disk that has a crew cabin around the equator of the sphere, equipped with a propulsive skin burning hydrogen and oxygen, either stored on board or from the atmosphere - using the Coanda effect to multiply lift. A 100 ft diameter sphere with two floors. This ship should be capable of orbiting the Earth and returning, as well as travelling to any point on Earth in a matter of 45 minutes or less.
Nanotube monocoque structrures used in architecture would revolutionize construction. Parts would be fabricated and nested together in quite compact forms given their thinness and easily transported anywhere. Geodesic structures of immense size could be easily erected anywhere with materials of this strength and lightness.
https://s-media-cache-ak0.pinimg.com...3848576a91.jpg
We can do amazing things with aluminum - we can do even better with nanotube materials!
Aircraft today are;
47% structure
15% payload
38% fuel
Going to
04% structure
15% payload
81% fuel
Increase the Brequet factor from 0.478 to 1.661 which is 3.474x the range!
A Boeing 737 goes from 4,304 km to 14,605 km range and its fuel goes from 23,170 litres to 49,237 litres as its structural weight falls from 45.4 tonnes to 4.0 tonnes using nanotube fibre.
https://upload.wikimedia.org/wikiped...k-20090105.png
Using slush liquid hydrogen at 90 kg/m3 at 200 bar, and 78.2 tonnes of hydrogen, on board (868,890 litres) multiplies range another factor of 3.08 or 44,983 km - allowing round the world flight without refuelling! This solves the problem of hydrogen distribution!
https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft
Another option of course would be to vastly improve payload!
Tiny drone craft would replace large airliners that are common today.
http://www.ehang.com/ehang184
Consider a payload equal to that of a typical passenger vehicle. 0.4 tonnes. Take off weight is 2.7 tonnes. Structure weight is 0.1 tonnes. That's how much nanotube material you need. This leaves 3.5 tonnes hydrogen fuel.. At 90 kg/m3 this occupies a volume of 38.9 cubic meters. Add in the volume of a luxury car interior (3.4 cubic meters) and you have a total volume of 42.3 cubic meters for the craft.
Contained within an oblate sphere 1.44 meters in height and 12.97 meters in diameter equipped with a propulsive 'smart skin' that propels the aircraft, guides it, senses the environment, and even renders it invisible when necessary
http://science.sciencemag.org/content/349/6254/1310
we have the first global flyer!
You can fly around the world in 90 minutes! Using electric propulsion!
http://www.sciencedirect.com/science...13468604006462
http://lae.mit.edu/ehd/
To keep the aircraft moving requires 92 MW of power to generate hydrogen from water.