Quiet Planes Make Good Neighbors

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

With this year’s Electric Aircraft Symposium just a few days away, the next few blog entries will close out reviews of presentations from EAS V. Krish J. Ahuja, Regents Professor at the School of Aerospace Engineering and the head of the Aerospace and Acoustics Technology Division at Georgia Institute of Technology, talked on “Quiet Propulsion for Small Electric Aircraft.” Dr. Ahuja came with great credentials, including his 1993 AIAA Aeroacoustics Award and being listed as one of top 50 Innovators by Aerospace magazine, 1995 and one of top 50 Technology leaders in the US by Industry Week Magazine. He started by examining the sources of aircraft noise.  Internal combustion engines (ICEs) are inherently noisy, but propellers add to that noise by their thickness, speed of rotation and the amount of loading they bear in producing thrust.  Converting air from low to high pressure as it moves through the propeller’s blades generates noise. Most annoying, the rasping shriek that comes from …

Electric, Small, and Challenging

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

Dr. Ilan Kroo, a professor of aeronautics and astronautics at Stanford and designer of the Swift ultralight hang glider, among others, has a different kind of mission – that of reshaping small aircraft for the greatest efficiency. Lessons learned from light aircraft can be applied on a larger scale – but keeping it simple and light to begin with allows less expensive learning, according to Kroo. The outline for his presentation at the fifth annual Electric Aircraft Symposium in Santa Rosa, California on April 29, 2011 is instructive. He had three major topics, all repeating the title for his talk; “Design Concepts for Small Electric Aircraft.” The first topic emphasized the word, “Electric,” the second, “Small,” and the third, “Design Concepts.” First he discussed why electric aircraft are of interest, including their environmental impact, efficiency, reliability, energy source independence, and that fact that they are scalable – the latter being important to anyone also designing lifting body airliners. Modern airliners …

Taking it to eXtremes

Dean Sigler Electric Powerplants, Sustainable Aviation 6 Comments

“If I were to make a prediction, I’d think there’s a good chance that it is not batteries. But capacitors.”  Karl Young, CEO of eXtreme Capacitor, Inc. started his presentation at the fifth annual Electric Aircraft Symposium with these words from Tesla Motor’s Elon Musk.  The reference to capacitors superseding batteries as an energy source for electric cars came from Musk’s address at the Cleantech Forum in San Francisco on 16 March 2011. Young’s talk before the April 29 gathering in Santa Rosa, California detailed the double-layer supercapacitors his company produces, and what Young feels are the advantages these have over “traditional” lithium and other batteries.  He is “trying to overcome the issues of batteries,” including, according to Young, their weight, slow charge and discharge times, their short operational lifetimes (typically 500 to 3,000 cycles), and their toxicity and flammability. Young contrasted that with the specifications for his eXtreme X-Cap™ “double-layer capacitor-based energy storage technology,” which can last through over …

Synergy: A Practical Lightplane for the New Century

Dean Sigler Diesel Powerplants, GFC, Sustainable Aviation 1 Comment

At EAS V, Synergy Chief Operating Officer John Paul Noyes framed his presentation of the Synergy aircraft by showing a picture of a 1973 portable telephone, then comparing it to a current model.  The clunky size, heft and limited utility of the former compared with its slim, feature-laden modern counterpart tells a story of intense design improvements, quantum increases in capabilities and far lower costs for a significantly better product – something usually anticipated in the history of modern products. Along with that historically comparative pairing, though, he showed pictures of a 1973 Cessna 182 and its Lycoming engine along with shots of modern examples of the two.  Not much other than the paint scheme distinguishes today’s Skylane from its antecedent.  Following Noyes’ outlook, it’s a bit disheartening to review Wikipedia’s specifications for 182s for the past 54 years.  Little, other than the introduction of improved instruments and Omni-Vision, has changed.  Although a great deal of this is due to …

Something(s) Amazingly New Under the Sun

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

To share an idea of how packed with information and inspiration an Electric Aircraft Symposium can be, I’m still writing reports on the fourth annual event, even though EAS V is coming up April 29 in Santa Rosa, California.  This is the next-to-last blog entry on last year’s presentations, and as noted in yesterday’s press release for the event, 2011’s will have at least as many presenters and material. Tyler MacCready is the son of Paul MacCready, founder of AeroVironment, Inc. and inspiration for many human-powered, ultralight, and solar-powered aircraft over the last several decades.  This author was in England when Bryan Allen pedaled Gossamer Albatross across the English Channel, a breakthrough in what was considered aerodynamically and structurally possible.  At age 14, Tyler had been the test pilot for the Albatross.  Such experiences led to his early work in solar-powered aircraft, as he told attendees at the fourth annual Electric Aircraft Symposium. Tyler was there as part of AeroVironment’s …

5th Annual CAFE Electric Aircraft Symposium Launches New Age of Flight

Dean Sigler Electric Powerplants, GFC, Sustainable Aviation 1 Comment

Dr. Brien Seeley, founder and President of the CAFE Foundation, shares this important news. SANTA ROSA, CA.—On April 29-30, 2011, an outstanding faculty from NASA, industry and academia will present the technologies necessary to inaugurate the Age of Electric Flight.  The 5th Annual CAFE Electric Aircraft Symposium (EAS V) will reveal how safe, emission-free, 2-4 seat electric aircraft could soon make a doorstep-to-doorstep round trip from San Francisco to Los Angeles on a single battery charge at nearly twice the overall trip speed of airline travel.  The latest breakthroughs in energy storage, motors, quiet propulsion, powered lift, electronic pilot assistance, autonomous flight and aerodynamics will be presented along with proposals for how they can transform transportation. EAS V will again network its faculty with the attendees, including venture capitalists, leaders of the aircraft industry, government researchers and aviation enthusiasts in the highly successful evening Theme Dinners in the Grand Ballroom of the Flamingo Resort and Spa in Santa Rosa, California.  As …