Ionic Thrusters Offer Quiet Flight

Dean Sigler Electric Powerplants, Feedback, Sustainable Aviation 1 Comment

Gizmag and Science Daily both covered a propulsion system that’s been with us for many decades, but which is just now seeing practical applications in space flight, and may be adapted to terrestrial winged vehicles. Your editor might have passed it over as overhyped, but the research came from the Massachusetts Institute of Technology (MIT) and was published in The Proceeding of the Royal Academy – two good indicators of veracity. Jennifer Chu of MIT’s News Office explains, “When a current passes between two electrodes — one thinner than the other — it creates a wind in the air between. If enough voltage is applied, the resulting wind can produce a thrust without the help of motors or fuel.”  That …

More Heat Than Light – But Energetic, Nevertheless

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Mars Curiosity Rover is bigger than one would expect, over six feet tall and weighing 1,982 pounds. It travels up to 660 feet per day on its multiple wheels, looking for rocks to analyze with its ChemCam. Powered by the heat from its plutonium reactor, Curiosity will rove Mars for two years if all goes well. The heat is converted to electricity (which then drives the wheel motors on the rover) by a lead telluride thermoelectric material, a semiconductor which, capable as it is, has been eclipsed in efficiency by a new form of the material developed by Northwestern University researchers. Mercouri G. Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern’s Weinberg College of Arts and …

Fixed Wings Find Their Way

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Dynamic presentations by Sebastian Thrun and Nicholas Roy have alerted and informed CAFE Foundation’s Electric Aircraft Symposia attendees of highly sophisticated efforts to allow autonomous full-size automobiles and miniature helicopters to navigate through or over unfamiliar terrain. Using clues from lasers, infrared sensors, inertial guidance systems and sometimes GPS coordinates, the vehicles use control algorithms to guide themselves around obstacle-strewn courses. As noted in Science Daily and the The Massachusetts Institute of Technology’s press office this week, “Dozens of research teams have competed in a series of autonomous-helicopter challenges posed by the Association for Unmanned Vehicle Systems International (AUVSI); progress has been so rapid that the last two challenges have involved indoor navigation without the use of GPS.” Mini-copters have …

Thomas Alva Would Be Proud

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

The best batteries as now produced use expensive materials and processes to achieve high energy density.  Could a century-old idea be resurrected to provide an inexpensive alternative to today’s costly electric storage devices?   Science Daily reports on a recent attempt to improve on a proven technology. Stanford University’s Hongjie Dai, professor of chemistry and head of a research group, is working with the Edison battery, named for Thomas Alva Edison, and using the nickel-iron electrodes Edison favored, but with a modern twist to overcome one of its disadvantages. Stanford’s news bulletin quotes Dai.  “The Edison battery is very durable, but it has a number of drawbacks. A typical battery can take hours to charge, and the rate of discharge …

Better Batteries: Wrap It in Seaweed

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

MIT’s Technology Review reported last September that researchers at the Georgia Institute of Technology and Clemson University had formulated a way to keep silicon anodes in lithium batteries from cracking under the strain of expending and contracting while they charge and discharge. They added a “binding agent and food additive derived from algae” that is in turn derived from seaweed. This enables the anode to charge and discharge at an eight times greater rate than an equivalent carbon anode without breaking down, a common problem for “raw” silicon. Environmentally friendly, the manufacturing processes for this type of anode are claimed to be clean and inexpensive. According to the Technology Review, “Lithium-ion batteries store energy by accumulating ions at the anode; …

Horizontal or Vertical, in the Air or on the Water

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

A 2008 ScienceDaily story was brought to light recently in the Minimalist Airplane Study Group, a Yahoo group dedicated to academic research on small aircraft. “In an advance toward introduction of an amazing new kind of internal combustion engine, researchers in China are reporting development and use of a new and more accurate computer model to assess performance of the so-called free-piston linear alternator (FPLA).” Their study of the FPLA, which could provide a low-emission, fuel efficient engine for future hybrid electric vehicles, was published in the August 27, 2008 issue of The American Chemical Society’s Energy & Fuels, a bi-monthly, peer-reviewed journal. Qingfeng Li, Jin Xiao and Zhen Huang explain in their paper that the FPLA has only one …

99.99 Percent Air, Thinner Than a Human Hair

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

ScienceDaily reports that, “A team of researchers from UC Irvine, HRL Laboratories and the California Institute of Technology have developed the world’s lightest material — with a density of 0.9 mg/cc — about one hundred times lighter than Styrofoam™.” Their findings appear in the Nov. 18 issue of Science. Looking a bit like a jacks matrix, this “micro-lattice” cellular architecture consists of 99.99 percent air and a lattice of interconnected hollow tubes with a wall thickness 1,000 times thinner than a human hair, according to Dr. Tobias Schaedler of HRL. Despite its extreme lightness, the advanced material is not flimsy.  Squeezing it to 50 percent of its original dimensions does not destroy the lattice.  Instead, it handles the high strain …

No Pain in This Membrane

Dean Sigler Electric Powerplants, Sustainable Aviation 9 Comments

On September 30, the National University of Singapore announced the world’s first energy-storage membrane, with the claim that it “outstrips existing rechargeable batteries and supercapacitors,” and according to Science Daily, “Surpasses existing rechargeable batteries and supercapacitors.” The cheese-cloth appearance looks a bit like a gauze bandage, but when sandwiched between what are alternatively described as two thin metal plates or two graphite plates can hold a significant charge much greater than that of conventional batteries or supercapacitors. The material, developed by a team from the National University of Singapore’s Nanoscience and Nanotechnology Initiative (NUSNNI), and led by principle investigator Dr Xie Xian Ning, is capable of holding a “charge at 0.2 farads per square centimeter. This is well above the …

Glass Like Metal, Plastic Like Steel

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

 Two very different materials forming techniques using materials that seem to defy their “normal” characteristics promise lighter, stronger, more efficiently manufactured products – with potential applications for green flight.  Dr. Seeley shared this item from Science Daily, regarding the potential use for this new material in the solar highways reported here.  One critique of that design is the need to maintain structural integrity with semi-trucks passing over a layer of glass through which everything from lane markers to warning messages could be displayed.  Jan Schroers, a materials scientist at Yale University, is experimenting with a new class of materials called bulk metallic glasses (BMG), or metal allows with randomly arranged atoms.  “Normal” metals have more well-ordered crystalline structures, but the …