SolarStratos Construction to Begin in January

Just as we have competing teams working out their plans to cross the Atlantic on electrically-powered wings, several projects are aiming high, attempting to reach altitudes normally achieved only by SR-71 pilots.  With balloon jumps topping 130,000 feet and the Perlan Project in final stages of construction for test flights early next year, the latest entrant in stratosphere-busting climbs will attempt the mission on batteries and solar power.

SolarStratos on its five-hour climb to 80,000 feet.  Rendering by SolarStratos

SolarStratos on its five-hour climb to 80,000 feet. Rendering by SolarStratos

Raphael Domjan, a self-described “eco-adventurer” and founder of Mission SolarStratos, will attempt by 2017 to top 80,000 feet in a two-seat, twin-motored craft designed and built by Calin Gologan and his PC-Aero team.  The airplane, a long-winged derivation of Gologan’s Elektra Two Solar, will rely on recent developments between Gologan and his American Partner, George Bye.  They’ve formed the American Electric Aircraft Corporation, dedicated to building, testing and certifying a two-seat trainer.

Solar Stratos has a 24.4-meter (80.8 feet) wing, 7.4 meters (9.84 feet) longer than that on the longest-span Elektra Two.  Somehow, PC-Aero has managed to add only 50 kilograms (110 pounds) to the Elektra’s 350 kilogram (770 pound) maximum takeoff weight for the larger craft.  Part of this may come from Solar Stratus’ short conventional gear, which replaces the retractable system on the Elektra Two.  Additional area for solar cells will allow the airplane to fly on solar power alone at its maximum altitude, necessary because the energy needed five-hour climb to maximum altitude will probably drain the 80 kilograms (176 pounds) of lithium-ion batteries on board.

Seeing "the stars at noon" will be part of voyages into the stratosphere.  Rendering by SolarStratos

Seeing “the stars at noon” will be part of voyages into the stratosphere. Rendering by SolarStratos

Domjan hopes to take others aloft to see the stars at noon and the curvature of the earth’s horizon, but passengers will have to be hardy souls willing to train for the serious business of wearing a lightweight pressure suit, the airplane’s own light weight not allowing pressurization.  Solar Stratos might benefit from the Perlan Project’s experiences with loaned NASA space suits.  Einar Enevoldson and Steve Fossett had issues even going to their 50,671 foot altitude record in 2006.

Raphael Domjan practicing free falls in the Realfly facility in Sion, Switzerland.  Photo courtesy SolarStratos

Raphael Domjan practicing free falls in the Realfly facility in Sion, Switzerland. Photo courtesy SolarStratos

Domjan is in training himself, according to this week’s Solar Stratos press release, working out in free-fall sessions at Realfly in Sion, Switzerland and presumably with jumps from altitude.  Geraldine Fasnacht, heading up security for the SolarStrator and Realfly teams, has assisted in training and preparations for the long flights ahead.  Making “dozens of jumps in the space of a few months, Domjan has also tested biomedical telemetry systems developed by the Swiss Centre for Electronics and Microtechnology (CSEM), while in simulated free fall at Realfly.

With construction of SolarStratos starting soon, Domjan can look forward to test flights by 2016 and by 2017 attaining “an altitude of around 80,000 feet (over 24 kilometers or 14.88 miles), where temperatures of about -70 ° C prevail.”  By 2018, the team hopes to start commercial flights to altitude.

The press release noted the presence of an elite support team.  “To meet this challenge, Raphael was already surrounded by a team of specialists, such as Michael Lopez-Alegria, astronaut and Flight Director Calin Gologan, engineer and manufacturer of the aircraft, Géraldine Fasnacht, wingsuit pilot, professional and responsible for flight safety rider, as well as other experts in engineering, meteorology, computer science and communication.”

Others include “Edgar Mitchell, the sixth astronaut to set foot on the moon in 1971, and lunar module pilot on the Apollo 14 Mission; André Schneider, vice president of the Ecole Polytechnique Federale de Lausanne (EPFL); Cedric Borboën, deputy director and wealth manager at Lombard Odier & Cie SA in Geneva, Founder & President of the Economic Forum North Vaudois; Miroslaw Hermaszewski, the first Polish astronaut, to have made a single flight as experimenter aboard Soyuz 30 in 1978; Raphael and his team are pleased to welcome these new sponsors eco-adventure SolarStratos.”

Domjan and his team look next to “open a door” on solar electric flight and near-space commercial trips for passengers and scientists.  Jean Verne, the grandson of Jules Verne, and Marie-Vincente Latécoère (from the Pierre-Georges Latécoère Foundation) support the project.

“Several partners have joined the adventure. This is Solstis SA, Horus Networks Sàrl, CSEM, PC-Aero GmbH, the City of Lausanne, e-Management, and RealFly Heli-Lausanne.”

Domjan’s ecologically-inspired adventurous spirit conquered the world’s oceans between September 2010 and May 2012 as he and a five-man crew sailed around the world using the energy generated by 500 square meters (5,382 square feet) of solar cells to power PlanetSolar, the world’s largest solar-powered boat.  He hopes to inspire others with his environmentally conscious adventures, while testing his personal limits and the limits of current technology.

Those wanting to support the effort will find varying levels of support, from a free subscription to the organization’s newsletter to a high-altitude flight in SolarStratos itself.  Under the heading “Be With Us,” SolarStratos promises the following: “You can join the club “SolarStartos” and follow us in our new venture. Everyone can join in the fun, but there [are] still 10 places for people wishing to live the adventure of solar flight in SolarStratos and approach some of our star, in silence. For 50,000 euros ($62,000), these future “StratosVoyagers” will live a unique experience, they will be the first passengers of a solar airplane and become ambassadors of the potential of renewable energy. This prestigious club will also fund the early stages of the project “SolarStratos.”

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“Inspired by nature’s own anti-turbulence devices – feathers,” researchers at RMIT University in Melbourne, Australia, have developed a system that emulates the movements of feathers with which birds control their flight path in the most turbulent conditions.

Dr. Case van Dam gave a talk at the 2014 Electric Aircraft Symposium on controlling aircraft in turbulence and providing smoother rides with Gurney flaps, jet flaps and micro tabs.  The RMIT team chose to mimic the motions of feathers on a bird’s wing to gain many of the same advantages.  The Unmanned Systems Research Team learned enough to file a provisional patent on the system, detecting disturbances in the air ahead of the airplane.  Both approaches might help the electric commuter aircraft proposed by Dr. Brien Seeley and Dr. Mark Moore as part of the hoped-for “pocket airpark” system.

Research supervisor Professor Simon Watkins explained the benefits of the University’s wind tunnel testing on a model of a small aircraft.   “By sensing gusts and disturbances in air flow through their feathers, birds are able to fly gracefully rather than bouncing around in turbulent air.  The system we have developed replicates this natural technology, with the aim of enabling planes to fly smoothly through even severe turbulence – just like birds.”

By sensing a flow disturbance in the air on the leading edge of the wing or even ahead of the wing, the system uses phase-advanced sensing, reacting to flow disturbances before they can affect the motion of the aircraft.

As with Dr. Van Dam’s systems,  “Professor Watkins said the system had great potential for all sizes of aircraft and could not only reduce the effects of turbulence on passengers but also reduce loads on plane wings, leading to lower fatigue and hence longer life.”

“’While we need to explore new sensor arrangements to apply this technology to larger and faster aircraft, we have proven the idea on the most challenging problem of keeping small, lightweight planes steady – since these are the ones that get bounced around the most,’ he said.”

Large model aircraft flies into wind-tunnel turbulence

Large model aircraft flies into wind-tunnel turbulence using the prototype anti-turbulence system developed at RMIT University

RMIT reports that the patent submission for a turbulence mitigation system for aircraft represents the successful outcome of PhD research by Abdulghani Mohamed, supervised by Professor Watkins and Dr. Reece Clothier in RMIT’s School of Aerospace, Mechanical and Manufacturing Engineering.  Mr. Mohamed’s contributions on turbulence theory and its effects on aircraft are acknowledged.

Earlier attempts to duplicate birds’ feathers reacting to turbulence or to provide flight control indicated some effects of the feathers on top of a bird’s wing enhancing control.  German experimenters attempted to duplicate this effect by applying a leather strip to one wing of a Messerschmidt Me-109 in 1938.  Later experiments titled “Separation Control on a Glider Wing with Artificial Bird’s Feathers” involved a section of a Stemme S10 that attempted to duplicate flight at low Reynolds numbers.

RMIT University (Royal Melbourne Institute of Technology) identifies itself as a global university, with campuses in Melbourne, Australia, two campuses in Vietnam, and an office in Barcelona, Spain.  The University also offers programs through partners in Singapore, Hong Kong, mainland China, Indonesia, Sri Lanka, Spain and Germany, and enjoys research and industry partnerships on every continent.

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Dr. Seeley provided this link to a story from China Daily this morning.  The blog reported on this airplane last year following its public debut, but this year, two examples showed up at the 10th China International Aviation and Aerospace Exhibition, also billed as Airshow China.  Held in Zhuhai, Guangdong Province, the show featured daily flight demonstrations by one of the two aircraft on display.

RX1E on display at

RX1E on display at the 10th China International Aviation and Aerospace Exhibition

China Daily followed its headline with this optimistic kickline, “Huge markets are expected for the versatile, eco-friendly 2-seat RX1E, then reports, “China will soon put its first domestically developed electric aircraft into mass production, and designers expect a huge market at home and abroad.”

“First” may be a dubious claim, with Tian Yu’s Greenwing International (Yuneec in China) e430 having flown five years ago, and having resumed flight testing in the US last year.  It may be true in the sense that Yuneec International now only shows drones, action cameras and powered skateboards on its page, with all aviation activities apparently transferred to its operations in California.

RX1E being assembled by students

RX1E being assembled by students

Designed by members of Shenyang Aerospace University in Liaoning Province, the airplane is expected to receive its airworthiness certificate from the Civil Aviation Administration of China “before the end of this year,” and will enter production in 2015.  Yang Fengtian, “an academic” at the Chinese Academy of Engineering and President of the Aerospace University, is obviously proud of the accomplishment.  “This will be the first electric aircraft to be certified by our civil aviation authority.  The success of our plane means China has become a technology leader in this field.”

In Shenyang, construction has started on a plant that can produce 100 RX1Es each year within three years.   Whether that rate will be achieved remains a matter for conjecture, with a price of 1 million yuan, or $163,000.  This will require the 1,000 sales Yang predicts as a demand from Chinese general aviation, but he sees markets for police patrols, flight training, “entertainment,” and mapping surveys.  He also sees market possibilities overseas, even though America’s FAA has yet to approve two-seat electric flight.  Yang says “many foreign enterprises have contacted us to express an interest in it.”  We can hope that interest equates to action on the part of the different foreign regulatory agencies.

The RX1E has a maximum take-off weight of 480 kilograms (1,056 pounds) and a maximum cruising speed of 160 kilometers per hour (99.2 mph).  Able to fly 90 minutes or 230 kilometers (142.6 miles) on a full charge of its 10 kilowatt-hour battery packs, the airplane should provide low-cost flight, with a five yuan ($1.00) fee  for a 40-minute recharge, with total operational costs at 20 yuan per hour.  The video leaves some question as to how many battery packs the aircraft carries, and how long they would need to charge for longer flights, but based on Yuneec’s similar design, at least four packs would probably be needed for a 90-minute flight.

Roland Bosch, an aircraft exhibition organizer from Germany, attended the Zhuhai show to invite Yang and the RX1E to display at a general aviation show back home.  “The RX1E’s design and engine are very good.  I believe it will be a big success in the global market because it is one of the best electric aircraft to my knowledge,” he said.

During the show, Mr. He Jun, Deputy Director of Liaoning General Aviation Institute and Mr. Tong Jianhui, General Manager of AVICLUB, signed an order for the first of the aircraft, indicating that production will commence on demand from the market.

We hope to report more on this promising design as details become available.

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400 Watt-Hours per Kilogram by 2014

On its web site, the company boasts, “OXIS Energy is leading the World with its latest cell Energy Density and Capacity,” and proceeds to announce that it’s “developed its largest Lithium Sulfur cell achieving in excess of 300 [Watt-hours per kilogram]. This outperforms Lithium ion technology that has dominated the performance battery market for many years. In addition OXIS has achieved an increase in cell capacity to a 25 Amp-hour (Ah) cell – a world first.”  They’re working toward a 33Ah cell.

Claiming a twelve-fold improvement in the last 18 months, OXIS, a British battery manufacturer, says it has the confidence to “achieve a cell capacity of 33Ah by mid 2015.”  The firm has hopes of energy densities “in excess of 400Wh/kg by the end of 2016 and in excess of 500Wh/kg by the end of 2018.” This doubling of energy density over the best of available lithium-ion batteries now would make the 175-mile-range Nissan Leaf a reality, and bring an end to most instances of “range anxiety.”  These would be admirable achievements for the nine-year-old company, which has 19 families of patents, with 60 patents granted and 55 pending.

Capable of almost 100-percent discharge with no ill effects, the batteries make allowances for ham-handed owners.  Perhaps more important, OXIS offers a battery not prone to sudden meltdowns.  Thermal runaways in lithium-ion cells is always a possibility, but OXIS is able to demonstrate freedom from that fear, first with a nail puncture test and second with a bullet test (in case you’re flying your electric airplane in a war zone – some of OXIS’s work is with defense companies).

Since there seems to be no thermal runway even in extreme circumstances, the batteries would work well in zero-tolerance for failure situations such as flying.  The firm explains, “The cells continue to display the enhanced safety features that characterise Li-S with superior safety performance attained in a barrage of industry-standard tests. “  A literal barrage, one might add.

According to OXIS, vehicle manufacturers are already reviewing and evaluating the cell technology. According to OXIS’ CEO, Huw Hampson-Jones, “OXIS Energy is set to remain at the forefront of the world’s leading battery technology with these significant improvement gains. They are being made in partnerships with British and European academic and research institutions such as LEITAT of Spain, TNO of the Netherlands and the Foundation for Research and Technology in Greece. OXIS is on schedule to release commercial cells for use in applications in the USA and Europe in 2015.” Lead partner in a three-year project to develop a “revolutionary Lithium Sulfur (Li-S) vehicle battery and Energy System Controller (ESC),” OXIS is working with Imperial College London, Lotus Engineering and others as part of the Revolutionary Electric Vehicle Battery (REVB) project, with the aims of creating batteries with greater range and safety at lower costs.

Perhaps overstating a bit, OXIS Energy CEO Huw Hampson-Jones says, “This program is significant in allowing OXIS to speed up the deployment of Li-S automotive battery systems for use in vehicles. The objective defined by the program will allow us to prove our ability to replace the petrol/diesel engine by 2016.” Possible hyperbole aside, OXIS seems like a company to follow as they continue to make progress toward a better, safer, lighter, cheaper battery.

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A Billion-Hole Battery

Battery companies and academic researchers keep finding ways to make ions flow quickly and efficiently within batteries. One way is to reduce the size of a cell so that the ions don’t have to travel far.  University of Maryland researchers may have achieved a miniaturization that boggles the mind.

Their claim, that they’ve created a “single tiny structure that includes all the components of a battery that they say could bring about the ultimate miniaturization of energy storage components, comes from a story by Martha Heil in UMD Right Now.

The structure is based on a nanopore, an incredibly tiny hole in a ceramic sheet 80,000 times thinner than a human hair.  The holes can hold electrolyte that carries a charge between the top and bottom surfaces of the ceramic sheet.  Millions of these holes poked through a postage stamp-sized sheet comprise a battery.  Researchers think the uniformity of the holes allows them to be packed tightly and efficiently together.  Even more astonishing, the space inside the millions of holes, according to UMD, “is so small that the space they take up, all added together, would be no more than a grain of sand.”

Holes form electrodes between top and bottom of film

Eleanor Gillette’s rendering of film, hole structure.  Holes form electrodes between top and bottom of film

Coauthor Eleanor Gillette’s modeling shows that the unique design of the nanopore battery is responsible for its success.

According to the report, the postage stamp performs well.  Chanyuan Liu, a Ph.D. student in materials science & engineering, reports it can be fully charged in 12 minutes and recharged thousands of times.

Having demonstrated the concept, researchers are now working on improvements that will make the next version 10 times more powerful.  At that point, the batteries may be able to be manufactured in large batches, making commercialization a possibility.

Now that the scientists have the battery working and have demonstrated the concept, they have also identified improvements that could make the next version 10 times more powerful. The next step to commercialization: the inventors have conceived strategies for manufacturing the battery in large batches.

The research was funded by the Department of Energy.

Gary Rubloff, director of the Maryland NanoCenter and a professor in the Department of Materials Science and Engineering and the Institute for Systems Research; Sang Bok Lee, a professor in the Department of Chemistry and Biochemisty and the Department of Materials Science and Engineering; and seven of their Ph.D. students contributed to the research and the resulting paper, published in the journal Nature Nanotechnology.  Students include Chanyuan Liu, Eleanor I. Gillette, Xinyi Chen, Alexander J. Pearse, Alexander C. Kozen, Marshall A. Schroeder, and Keith E. Gregorczyk.

The abstract for the paper gives more detail on what they managed to cram into those holes.

Nanopores show remarkable similarity in size, considering nanoscale in which they exist

Nanopores show remarkable similarity in size, considering nanoscale in which they exist

A single nanopore structure that embeds all components of an electrochemical storage device could bring about the ultimate miniaturization in energy storage. Self-alignment of electrodes within each nanopore may enable closer and more controlled spacing between electrodes than in state-of-art batteries. Such an ‘all-in-one’ nanopore battery array would also present an alternative to interdigitated electrode structures that employ complex three-dimensional geometries with greater spatial heterogeneity. Here, we report a battery composed of an array of nanobatteries connected in parallel, each composed of an anode, a cathode and a liquid electrolyte confined within the nanopores of anodic aluminium oxide, as an all-in-one nanosize device. Each nanoelectrode includes an outer Ru nanotube current collector and an inner nanotube of V2O5 storage material, forming a symmetric full nanopore storage cell with anode and cathode separated by an electrolyte region. The V2O5 is prelithiated at one end to serve as the anode, with pristine V2O5 at the other end serving as the cathode, forming a battery that is asymmetrically cycled between 0.2 V and 1.8 V. The capacity retention of this full cell (relative to 1 C values) is 95% at 5 C and 46% at 150 C, with a 1,000-cycle life. From a fundamental point of view, our all-in-one nanopore battery array unveils an electrochemical regime in which ion insertion and surface charge mechanisms for energy storage become indistinguishable, and offers a testbed for studying ion transport limits in dense nanostructured electrode arrays.

Editor’s Note: The use of Ru (Ruthenium) nanotubes might make the battery somewhat pricey (Ru hovers around $60 per troy ounce), but then again, the extremely small size of each component in the battery would keep such costs low.

 

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A research team at Australia’s Queensland University of Technology combined talents with scientists at Rice University in Houston, Texas to produce all-carbon structural panels that rival the best lithium-ion batteries for energy density, but can also be charged as quickly as supercapacitors.  In fact, the panels are supercapacitors, “a ‘sandwich’ of electrolyte between two all-carbon electrodes,” made into “a thin and extremely strong film with a high power density,” according to researchers.

These lightweight supercapacitor panels can be combined with “regular” batteries to “dramatically boost the power of an electric car.”  This application would not be unlike Dr. Emile Greenhalgh and Volvo’s structural/electrical body panels.

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Courtesy of Nunzio Motta/Queensland University of Technology

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Photo courtesy of Nunzio Motta/Queensland University of Technology

Postdoctoral Research Fellow Dr Jinzhang Liu, Professor Nunzio Motta and PhD researcher Marco Notarianni, from QUT’s Science and Engineering Faculty – Institute for Future Environments, and PhD researcher Francesca Mirri and Professor Matteo Pasquali, from Rice University in Houston, in the United States, created this breakthrough.  They think the film could be embedded in a car’s body panels roof, doors, bonnet (hood to you Yanks) and floor.  Their ability to charge like a supercapacitor could “turbocharge” an electric car’s battery in just a few minutes, according to the researchers.

Mr. Notarianni explained the advantages of combining batteries and supercapacitors: “Vehicles need an extra energy spurt for acceleration, and this is where supercapacitors come in. They hold a limited amount of charge, but they are able to deliver it very quickly, making them the perfect complement to mass-storage batteries.  Supercapacitors offer a high power output in a short time, meaning a faster acceleration rate of the car and a charging time of just a few minutes, compared to several hours for a standard electric car battery.”

Queensland University's Supercapacitor Laboratory and its head, Dr.

Queensland University’s Nanotechnology Laboratory and Dr.Nunzio Motta with one of its powerful microscopes.  Photo courtesty QUT

Dr. Liu noted that supercapacitors combined with batteries offer a “substantial weight reduction and increase in performance.  “In the future, it is hoped the supercapacitor will be developed to store more energy than a Li-Ion battery while retaining the ability to release its energy up to 10 times faster – meaning the car could be entirely powered by the supercapacitors in its body panels. After one full charge this car should be able to run up to 500 kilometers (310 miles) – similar to a petrol-powered car and more than double the current limit of an electric car.”

He sees the potential for rapid charging of other devices; “For example, by putting the film on the back of a smart phone to charge it extremely quickly,”

The low costs of an all-carbon-based supercapacitor body panel could change future auto markets, researchers hope.  “We are using cheap carbon materials to make supercapacitors and the price of industry scale production will be low,” Professor Motta predicts.  “The price of Li-Ion batteries cannot decrease a lot because the price of Lithium remains high. This technique does not rely on metals and other toxic materials either, so it is environmentally friendly if it needs to be disposed of.”

While the costs of carbon products decrease in the future, the prices of lithium remains high, another benefit of having an all-carbon structure.  “This technique does not rely on metals and other toxic materials either, so it is environmentally friendly if it needs to be disposed of.”

The researchers are part of QUT’s Battery Interest Group, a cross-faculty group that aims to engage industry with battery-related research.  Their findings are published in the Journal of Power Sources and the Nanotechnology journal.

The abstracts for the two papers show differing perspectives:

Journal of Power Sources

We fabricated high performance supercapacitors by using all carbon electrodes, with volume energy in the order of 10−3 Whcm−3, comparable to Li-ion batteries, and power densities in the range of 10 Wcm−3, better than laser-scribed-graphene supercapacitors. All-carbon supercapacitor electrodes are made by solution processing and filtering electrochemically-exfoliated graphene sheets mixed with clusters of spontaneously entangled multiwall carbon nanotubes. We maximize the capacitance by using a 1:1 weight ratio of graphene to multi-wall carbon nanotubes and by controlling their packing in the electrode film so as to maximize accessible surface and further enhance the charge collection. This electrode is transferred onto a plastic-paper-supported double-wall carbon nanotube film used as current collector. These all-carbon thin films are combined with plastic paper and gelled electrolyte to produce solid-state bendable thin film supercapacitors. We assembled supercapacitor cells in series in a planar configuration to increase the operating voltage and find that the shape of our supercapacitor film strongly affects its capacitance. An in-line superposition of rectangular sheets is superior to a cross superposition in maintaining high capacitance when subject to fast charge/discharge cycles. The effect is explained by addressing the mechanism of ion diffusion into stacked graphene sheets. 

Nanotechnology

Flexible graphene-based thin film supercapacitors were made using carbon nanotube (CNT) films as current collectors and graphene films as electrodes. The graphene sheets were produced by simple electrochemical exfoliation, while the graphene films with controlled thickness were prepared by vacuum filtration. The solid-state supercapacitor was made by using two graphene/CNT films on plastic substrates to sandwich a thin layer of gelled electrolyte. We found that the thin graphene film with thickness <1 μm can greatly increase the capacitance. Using only CNT films as electrodes, the device exhibited a capacitance as low as ~0.4 mF cm−2, whereas by adding a 360 nm thick graphene film to the CNT electrodes led to a ~4.3 mF cm−2 capacitance. We experimentally demonstrated that the conductive CNT film is equivalent to gold as a current collector while it provides a stronger binding force to the graphene film. Combining the high capacitance of the thin graphene film and the high conductivity of the CNT film, our devices exhibited high energy density (8–14 Wh kg−1) and power density (250–450 kW kg−1).

Of course, here we would like to see the technology refined to the point of becoming the shells of our future flyers.  Where there is progress, there is hope.

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Jean-Luc Soullier and Roman Marcinowski forge ahead on two fronts to set electric flight records.  Longer term, we hope to see first flights of their motorized Windward Performance Duckhawk, modified for long-distance flights and a crossing of the Atlantic Ocean – perhaps as early as next year.

In the meantime, they are putting the finishing touches on their already record-setting Colomban MC-30 Luciole (Firefly), now with its third motor, significantly larger and more powerful than previous powerplants.  Making an initial test flight on October 30, Jean-Luc managed an impressive climb rate, even at partial power.

Last year, the team stated their hoped-for records to come.

Our next targets are :
Spring/Summer 2014
New FAI world records :
- Speed : minimum 200 Km/h (124 mph)
- Distance : minimum 2,000Km ( 1,250 miles )  (This will probably be accomplished with the Duckhawk.)
- Altitude : minimum 10,000 meters ( 32,800 Ft ) (Again, probably with the Duckhawk, although Roman says, “let’s see what the actual MC30E will allow.” ) 

Substantial and beautifully crafted motor mount shows serious attention to detail

Substantial and beautifully crafted motor mount shows serious attention to detail.  Actual motor, controller and other technical details are confidential until records are established

The first flight of the newly configured Luciole was “to verify the longitudinal controllability (in consideration of the new centering), the functioning of the adjustable pitch propeller and the electric stability of the set batteries + controller.”  Positive results on all counts give great hopes for the ensuing trials.

Jean-Luc was gentle on the throttle with only partial power used even in the climb.  Despite the moderation, the airplane showed a peak rate of climb of seven meters per second (1,388 feet per minute) and reached 2,850 feet in quick order.  It also, again at a modest throttle setting, achieved a maximum true airspeed of 151 kilometers per hour (93.62 mph).  Since earlier tests with a smaller motor, but the same propeller had shown 120 kph (74.4 mph) at only 5.5 kilowatts energy use, it’s obvious the new setup has a great deal of promise for going after more FAI world records.

Roman Marcinowski (standing) and Jean-Luc Soullier analyze data from their proprietary "Aeroskysoft" software

Roman Marcinowski (standing) and Jean-Luc Soullier analyze data from their proprietary “Aeroskysoft” software

Jean-Luc thanks the artisans who repaired the raised landing gear, which he notes was too soft on all axes.  The repaired and newly stiffened gear now displays “stable and pleasant behavior on the ground, a real progress.”

Long, spindly landing gear is newly repaired and strengthened.  Carbon fiber tubes on wingtips could reduce tip vortices

Long, slender landing gear is newly repaired and strengthened. Carbon fiber tubes on wingtips could reduce tip vortices

The electric Luciole will sport Dr. Sumon Sinha’s deturbulator tape, already proven on early record flights on the airplane, and possibly a different approach to reducing wing-tip drag associated with rectangular wing planforms.  The cylinders at each wingtip ostensibly straighten the outward flow that would otherwise lead to induced drag tip vortices.  Whether these will be used or not is speculation at this point, since pictures on several web sites show the airplane with and without them.

Dr. Sinha's deturbulator tape shows as gray line across span

Dr. Sinha’s deturbulator tape shows as gray line across span

Coming flights will test the new propeller blades manufactured by Arplast (which also manufactured the variable pitch hub).  The original blades suffered a bit from the powerful motor.  With the care he exercises on all his test flights, Jean-Luc will advance toward maximum performance, testing the limits of the small plane and preparing to demonstrate its performance capabilities to the world.

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Rice University scientists who want to gain an edge in energy production and storage report they have found it in molybdenum disulfide. 

From Wikipedia: “Molybdenum disulfide is the inorganic compound with the formula MoS 2. The compound is classified as a metal dichalcogenide. It is a silvery black solid that occurs as the mineral molybdenite, the principal ore for molybdenum.   MoS 2 is relatively unreactive. It is unaffected by dilute acids and oxygen. In appearance and feel,molybdenum disulfide is similar to graphite. It is widely used as a solid lubricant because of its low friction properties and robustness.”

Molybdenum disulfide's edge

A new material based on molybdenum disulfide exposes as much edge as possible for efficiency as a catalyst for hydrogen production or for energy storage.  Photo: Tour Group

Let’s break down one probably unfamiliar term (it was to your editor).  A chalogen is one of the members of the Vla group in the periodic table and includes oxygen, sulfur, selenium, tellurium, and polonium.  Add a more electropositive element to one of those and we get a chalogenide.  Double down and make it a dichalogenide, in this case a material that looks similar to graphene, but more three-dimensional, with three layers because it has slab of molybdenum sandwiched between two layers of sulfur atoms.

According to James Tour, Rice professor and head of his own laboratory at Rice, MoS looks like graphene when viewed from above, with rows of ordered hexagons.  The sandwich layers, though, help “create a more robust edge, and the more edge, the better for catalytic reactions or storage.”  Paradoxically, it doesn’t react with much, but works well as a catalyst.

Tour, a post-graduate researcher named Yang Yang, and graduate student Huilong Fei, and other colleagues turned this sandwich into a thin film and found that it catalyzes the separation of hydrogen from water when exposed to an electrical current.  This performance in creating a hydrogen evolution reaction (HER) “is as good as any molybdenum disulfide structure that has ever been seen, and it’s really easy to make,” Tour said.

They grew their porous molybdenum oxide film onto a molybdenum substrate using room-temperature anodization, often used to “thicken natural oxide layers on metals.”  Their cost-effective and low temperature method created a thin, flexible film that maximizes the amount of exposed edge, which seems to make it a great material for hydrogen generation, possible fuel cell use, and as a component of supercapacitors.

Tour Lab's film

Tour Lab’s film shows flexibility, excellent energy storage capabilities.  Photo: Tour Group

Tour explained, “So much of chemistry occurs at the edges of materials. A two-dimensional material is like a sheet of paper: a large plain with very little edge. But our material is highly porous. What we see in the images are short, 5- to 6-nanometer planes and a lot of edge, as though the material had bore holes drilled all the way through.”

Exposure to sulfur vapor at 300 degrees Celsius (572 degrees Fahrenheit) for an hour converted the film to molybdenum disulfide without damaging its porous structure.

In supercapacitors, this film has a long lifespan, and while not producing the energy storage of batteries, can charge and discharge quickly.  Tour’s group made supercapacitors from the films, and in tests, they “retained 90 percent of their capacity after 10,000 charge-discharge cycles and 83 percent after 20,000 cycles.”

Rice reports, “’We see anodization as a route to materials for multiple platforms in the next generation of alternative energy devices,’ Tour said. ‘These could be fuel cells, supercapacitors and batteries. And we’ve demonstrated two of those three are possible with this new material.’”

The Rice research, authored by Tour, Yang Yang, Huilong Fei, Gedeng Ruan and Changsheng Xiang,  appears in the journal Advanced Materials.

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H2, Where Are You?

Elon Musk publicly disdains hydrogen-powered automobiles, but then he has $5 billion riding on his battery megafactories and continued success with his Tesla line of automobiles.  Others with a more disinterested point of view discuss H2’s difficulties – and its promise as a vehicle fuel.

America, for instance, has a mere 128 hydrogen fueling stations, and the European Union only 143 as of February 2012.  Even with planned expansion of this infrastructure (California is spending $180 million in private and public funds on a planned 46 stations), the landscape might not be ready for large numbers of fuel cell vehicles for a decade or more.

For comparison, there are about 29,000 battery-charging stations in the U. S., with both government and private enterprise offering such services.  The Kohls store and all Walgreens Pharmacies in my area have plug-in stations for EVs, for instance, and the I-5 freeway, from British Columbia to Baja, California, has stations every 25 to 50 miles.  With battery-powered EV and hybrid sales exceeding 250,000 in the last decade, this technology is an accepted part of the transportation infrastructure.

Highly modified Lange Antares flies on fuel cells powered by hydrogen in large wing tanks

Highly modified Lange Antares flies on fuel cells powered by hydrogen in large wing tanks

Because, at least in battery-supporting developers’ minds, hydrogen has issues that require solutions before it can become a viable liquid fuel or power fuel cells for millions of vehicles.

To counter the objections, the U. S. Energy Department has launched the $1 million H2 Refuel H-Prize.  “This two-year competition challenges America’s engineers and entrepreneurs to develop affordable systems for small-scale, non-commercial hydrogen fueling. These projects will continue to deploy hydrogen infrastructure across the country to support more transportation energy options for U.S. consumers, including fuel cell electric vehicles (FCEVs).  Successful entries will install and test systems that generate hydrogen from resources available at most homes, like electricity or natural gas, and provide the hydrogen to fuel vehicles. This competition plans to offer a $1 million cash prize to the team that demonstrates the best system.”

The Department notes that, “Hydrogen infrastructure remains the most critical barrier to the widespread adoption of FCEVs,” and that “both government and industry are focused on identifying actions to encourage early adopters of FCEVs, by conducting coordinated technical and market analysis and leveraging other alternative fueling infrastructure to enable cost reductions and economies of scale. For example, infrastructure being developed for alternative fuels such as natural gas, as well as fuel cell applications including combined heat and power, backup power and fuel cell forklifts, can help pave the way for mainstream hydrogen vehicle infrastructure.”

ENFICA by Turin Polytechnic professor Giulio Romeo has flown since 2010, set records.  Model below uses fuel cells, solar power to stay aloft for extended periods

ENFICA by Turin Polytechnic professor Giulio Romeo has flown since 2010, set records. Model below uses fuel cells, solar power to stay aloft for extended periods

The Energy Department takes credit for reducing the cost of automotive fuel cells by 50 percent since 2006, doubling fuel cell durability and reducing the amount of platinum by 80 percent since 2005.  Their H-Prize competition will provide incentives to teams who will have one year to design a system, find partners and a site to install that system, “and register for the competition before submitting data and designs to a team of independent judges.”  The judges will select top teams as finalists, who will then have seven months to build, install and prepare their systems for testing.

Registration to compete in the H-Prize and more information is available on the H2 Refuel website.

In recent workshops with industry leaders, the DOE has discussed goals of producing low-cost hydrogen at $2.30 per kilogram for “forecourt” or on-site production (1,500 kg/day) and $2.00 per kilogram for centralized (50,000 kg/day) by 2020, and reducing hydrogen delivery from the point of production to the point of use in consumer vehicles to <$3/gallon of gasoline equivalent (gge) by 2015 and to <$2/gge by 2020 (delivery only, all costs in 2007$).

Since the Toyota FCV holds five kilograms of H2 in two 10,000 pounds-per-square-inch pressurized tanks, delivery of such fuel requires larger, extremely high-strength tanks for storage or transportation – one challenge to confront.  Luckily, aerospace manufacturers have created processes such as filament winding to make such tanks lightweight as well as strong.

But the $2 gge fuel cost would mean a measly $10 per tankful on the FCV, good for over 300 miles, and very competitive with batteries.  Consumer Reports lists the vagaries of current pricing: “There is no established cost for a kilogram of hydrogen but at a Washington, D.C., station several years ago it went for about $8 per kg. That would work out to about 13 cents per mile, which is much more than an electric vehicle (typically 3 to 5 cents). Still, Toyota is likely to provide free hydrogen fill-ups as part of the lease plan or purchase price. That follows the lead of Hyundai, which offers a fuel-cell version of the Tucson SUV.  A Department of Energy study estimates a cost of $4.49/kg for dispensed hydrogen from natural gas.”

In follow-up entries, we’ll look at whether fuel cell-powered aircraft make sense from a physical and economic sense, new technologies that show promise for EV use, and the environmental costs, as well as benefits, of hydrogen power.

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Solar Flight SUNSTAR – a New High-Flyer

Eric Raymond has been designing and building solar-powered aircraft for 28 years, and flew Sunseeker 1 across the United State in 1990, Sunseeker 2 over the Alps in 2009, and has started touring Italy in the world’s first two-seat sun-powered aircraft, the Duo.  After three such outstanding efforts, what direction will his new design take?

He took away any mystery on that today by unveiling his fourth aircraft, an optionally manned, high altitude platform, SUNSTAR.  Eric claims, “more performance potential than any of the other projects now under development.

“Compared to other solar UAVs (unmanned aerial vehicles) being developed, the Sunstar promises higher flight speeds in a turbulence-tolerant design, for operation in real world conditions.”

“Sunstar takes advantage of sailplane aerodynamic design philosophy to achieve the lowest possible power requirement to maintain flight at high altitudes.”  It takes technology tested on the Sunseeker Duo “to a whole new level.”

Having reached station altitude, the central, pusher propeller can deploy.  Its slow turning will use minimum power for greatest endurance

Having reached station altitude, the central, pusher propeller can deploy. Its slow turning will use minimum power for greatest endurance.  Illustration courtesy Solar-Flight

Capable of unmanned flight for months at a time, the airplane can also fly with a pilot for shorter missions, but its primary mission is as an unmanned telecommunications platform, staying on station longer than humanly tolerable.  Eric Raymond adds this perspective, “”What we are designing is known as an atmospheric satellite, which operates and performs many of the functions as a satellite would do in space, but does it in the atmosphere. Uplink and downlink speeds will be far better than a satellite, due to the shorter distance (than from a space satellite).”  At the same time, one Sunstar aircraft serves a much larger ground area than any land-based tower.

The airplane, now in advanced design stage, will have the best coverage of solar cells ever achieved, according to Solar-Flight.   “A proprietary lamination of a new type of solar cell forms a perfectly smooth skin. For maximum power at low sun angles some solar arrays are mounted on the sides of the aircraft.”

With pusher propeller holding altitude on minimum power, "climb" propellers fold neatly onto sides of nacelles for minimum drag.  Courtesy: Solar-Flight

With pusher propeller holding altitude on minimum power, “climb” propellers fold neatly onto sides of nacelles for minimum drag. Illustration courtesy Solar-Flight

The three-motor configuration allows the airplane to take off on the front motors, climb to altitude, and deploy the very large pusher propeller at the rear of the cargo/pilot pod.   Once that propeller, optimized for high altitude, holds the airplane’s station altitude, the two motors on the booms shut down and their propellers fold back to minimize drag.  Solar-Flight adds, “This central motor is designed for the low power cruise condition, for minimal power consumption while on station.

In an email, Eric explains, “There are good reasons for this configuration.  If you remember, when the Voyager flew around the world, they shut off an engine for more efficient cruising.  In this case, the very large prop needed for high altitudes can’t get enough ground clearance, so take off is performed with that prop folded back, as per the attached renderings.”

Sunstar showing folded rear propeller which can only be opened when the airplane is at altitude

Sunstar showing folded rear propeller which can only be opened when the airplane is at altitude.  Illustration courtesy Solar-Flight

Eric shares his long-term hopes for the project.  “…We will not start construction until enough funding is in place to finish the prototype.  Our business plan details two years to first flight, and production examples could be flying a year after that.  A lot depends on payload requirements.”

Sunstar’s design relies on a modular system configurable for a variety of missions. The interchangeable central pod can acts as a multi seat cockpit, or an un-manned instrument pod. “A pressurized cockpit for the occupants is also in the planning stage. The wingspan can be changed for different missions, by eliminating some wing sections. “

To be flown initially with a pilot on board, then optionally manned, the airplane will eventually achieve fully autonomous operation, subject to the governing country’s regulations.   “The inclusion of a manned cockpit in the prototype allows much more freedom in testing, considering the restrictions placed on un-manned aircraft over populated areas.”  From the beginning, all controls will be “fly-by-wire,” probably necessary because of the long span and the ability to add and remove wing panels for different missions.  Prototypes of SUNSTAR’s systems are already flying in Solar Flight’s flagship, the Sunseeker Duo.

All systems to be used on Sunstar have been tested on the Sunseeker Duo.  Photo courtesy Solar-Flight

All systems to be used on Sunstar have been tested on the Sunseeker Duo. Photo courtesy Solar-Flight

Eric hopes to attract strategic partners, who would be able “to help define mission-specific optimization and bring the project to completion.”  Eric invites those with an interest in developing this project to “Visit our web site for in flight video footage of our current state-of-the-art solar powered airplanes.”

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