Solarimpulse.com reports, “The Boeing 747 landed at Moffett Airfield in San Francisco at 1:13 PM (UTC-8) on Thursday 21 February. HB-SIA was immediately unloaded and, in the coming days reassembly will begin.” Almost immediately, crews will assemble and test fly the already intercontinental solar-powered aircraft in preparation for a flight from the Bay Area to the East Coast. Having conquered the gap between Europe and Africa on its trip to Rabat, Morocco and on to Quarzazate, HB-SIA braved turbulence and gusting that caused it to turn back on its initial foray into the desert. Its final arrival at a gigantic solar energy plant in Morocco’s interior was a symbol of what clean energy can accomplish and a tribute to Solar Impulse’s pilots’ skills and the team’s imaginative creation. Now, the Airbus-sized vehicle is being readied for flight testing, with possible appearances at the seventh annual Electric Aircraft Symposium and its Cross America 2013 tour. HB-SIA’s recent trip from Payerne, Switzerland …
A Fix for Dreamliner Battery Woes?
With Boeing facing financial doldrums because of its ongoing grounding and resulting slump in sales of the 787 Dreamliner, the stakes are high for the company. That makes today’s Reuters’ report that the manufacturing giant may have found a “way to fix battery problems on its grounded 787 Dreamliner jets” good news for not only Boeing, but for electric aircraft in general. Readers should read these findings with some caution, though, since another report from Japan gives a different possible cause for the problems. That said, the two reports might not be mutually exclusive. Many electric light aircraft developers use spacing between cells and some method to circulate cooling air over them. In Boeing’s two 787 lithium battery packs, eight large cells fill a fairly tight housing. Reuters quotes an anonymous source, “’The gaps between cells will be bigger. I think that’s why there was overheating,’ said the source, who declined to be identified because the plans are private. “A …
Chew on This: How a Snail Might Teach Us How to Make Better Batteries
Radula: A flexible tonguelike organ in certain mollusks, having rows of horny teeth on the surface. [Latin r dula, scraper, from r dere, to scrape] freedictionary.com The Gumboot Chiton is not pretty, and is downright ugly when turned over. The rows of molars on its underside are wonderfully suited though, to scraping algae off rocks, and the hardness of its dentures is something materials scientists study closely. The Chiton, described as a “wandering meatloaf” because of its hump of leathery brown upper skin, may not have an alluring personality, but is teeth are magnetic, leading to University of California, Riverside assistant professor David Kisailus’ attraction to them. Kisailus, specializing in chemical and environmental engineering, and his fellow researchers may have found lessons in nature, and in the mouth of this marine snail, “to create less costly and more efficient nanoscale materials to improve solar cells and lithium-ion batteries,” according to the University. Up to a foot long, “Chitons have evolved to …
Cheaper, Lighter, Stronger – But When?
We’d all love to see the battery that’s lighter, stronger, charges like a capacitor and costs next to nothing. We’d all be driving electric cars and those of us who wanted battery-powered airplanes would be designing the next new wave of flight. Usually, these things are a decade or more away, following excruciating intervals of study, commercialization and usually, much-delayed or postponed production. Dr. Chongwu Zhou, a professor at the University of Southern California’s (USC’s) Viterbi School of Engineering, claims to have such a battery under provisional patent, and potentially available commercially within “two or three years,” according to school press releases. The battery uses porous silicon nanoparticles to replace traditional graphite anodes and provide superior performance – three times as much energy as a graphite-based lithium battery and capable of being recharged within only 10 minutes. Zhou says, “It’s an exciting research. It opens the door for the design of the next generation lithium-ion batteries.” Zhou worked with USC graduate …
A Tea Room in the Sky
Richard Glassock is an Australian graduate student and designer working in autonomous aircraft, long-distance sailboats, and a light hybrid power system made from off-the-shelf model aircraft components. He’s even made a design study of something that would really cause a stir in the world of electric sailplanes. “I just want to send you some pictures of a concept model I’m working on. The idea is for a 6- seat sailplane, I thought about this 10 or 15 years ago when I first started getting to cloudbase in a hang glider. It is a magical world, particularly in an open air type vehicle: wouldn’t it be wonderful to share with friends. Now it seems to have turned out to be an 8-seat [sailplane with] twin electric propulsion. Somehow the canopy will stow for open top operations, while there is room for the bathroom, coffee machine, oven etc. Designed for cloudbase tea and scones [or a] gliding chess club with excellent views, …
Alchemy with Thin Film Structures
The blog has looked at several recent attempts to pull electricity from solar cells that have the ability to capture a broad range of light wavelengths. These are based on everything from layers of graphene and zinc nano-wires, to an exotic subwavelength plasmonic cavity, to straining solar cells to form wide bandgap funnels which capture light’s energy. Joining these efforts along with those of researchers in America and Germany, colleagues at the Vienna University of Technology are testing single atomic layers of oxide heterostructures, a new class of materials, to “create a new kind of extremely efficient ultra-thin solar cells.” Professor Karsten Held from the Institute for Solid State Physics at the University, explains, “Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own.” Researchers used large-scale computer simulations to discover that these layered structures “hold great potential for building solar cells.” …
Taxiing, Run-ups and Braking – Then Maybe Flying
Frédéric Laude reported the near-flight condition of his team’s CC01e on Sunday, February 3 on the team’s blog. We’ve been following the progress of the airplane for several months. A very small canard, with a pilot tucked into a slim, minimal fuselage just ahead of its small Electravia motor, the plane was taken from its hangar and assembled this week despite the cold, wintry day. Frédéric reports that the team chocked the wheels and started to test motor and battery power, reaching 250 Amps and 3,500 rpm at the propeller. 200 Amps gave 3,200 rpm, and 150 Amps produced 2,900 rpm, even with cold batteries. He notes that this is all much simpler than trying to run the original not-so-quiet two-stroke engine. For the video, the motor’s top cover was left off, but will be replaced for flight testing, and a final spinner will cover the propeller hub after the first flight. Unfortunately, the video is not yet on YouTube, …
Solar Flight on a Winter Wave
Eric Raymond sent the following today. “Had a nice SUNSEEKER flight today, 3 hours, and as usual I could have stayed up into the dark, even in January! This time there was wave lift, but very weak, despite 30 knot winds at 6700 meters (21,500 feet). “In the pictures you can see the inversion clearly, and the Adriatic covered in a blanket of clouds. “My batteries are very old and cold, but I still got high enough to connect with the wave, which went on forever. “Taxing was tricky because of big lumps of snow, so I landed downwind, as the taxiway is not cleared. Both his Solar Flight website News and Blog show more, including the construction of the Sunseeker Duo, the world’s first two-seat solar-powered airplane. One blog entry in particular, shows a flight from Slovenj Gradec to Lesce Bled airport, on its way to Switzerland for an airshow. He topped Mount Triglav, the highest peak in Slovenia, and …
The Layered Look in Batteries
Gurpreet Singh, assistant professor of mechanical and nuclear engineering, and his research team at Kansas State University in Manhattan, Kansas, are working out less expensive, more efficient ways to create nanomaterials and lithium-ion batteries. “We are exploring new methods for quick and cost-effective synthesis of two-dimensional materials for rechargeable battery applications,” Singh said. “We are interested in this research because understanding lithium interaction with single-, double- and multiple-layer-thick materials will eventually allow us to design battery electrodes for practical applications. This includes batteries that show improved capacity, efficiency and longer life.” Researchers grew graphene films on copper and nickel foils in less than 30 minutes by quickly heating them in a furnace in the presence of argon, hydrogen and methane gases – significantly at atmospheric pressure. Not needing to use a vacuum to create these films saves energy, time and cost, according to Singh. Researchers used the films to create the negative electrode of a lithium-ion cell and test the …
Fire Spotting, Fiber Optics and Intelligent Control
Ikhana, a civilian version of the military’s Predator drone, has been used for years at the NASA Dryden Flight Test Center for a multiplicity of roles. Beginning in 2006, Ikhana carried onboard sensor systems that spotted and tracked wildfires for ground and air-based firefighters. Ikhana was also used to evaluate advanced sensing technology installed on its wings to improve its efficiency. The sensors incorporated fiber optic sensing technology, and were located side by side with traditional sensors. One NASA researcher noted, “There are 3,000 sensors on Ikhana that are imperceptibly small because they’re located on fibers approximately the diameter of a human hair.” Weight savings on an aircraft with an array of fiber optics would reduce operating costs and improve fuel efficiency, according to NASA. But these new sensors also “enable adaptive wing shape control.” NASA’s Lance Richards, of Dryden’s Advanced Structures and Measurements Group, says, “’Active wing-shape control represents the gleam in the eye of every aerodynamicist. If the …