{"id":8303,"date":"2013-09-28T15:29:02","date_gmt":"2013-09-28T22:29:02","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=8303"},"modified":"2013-09-28T15:29:02","modified_gmt":"2013-09-28T22:29:02","slug":"designing-airplanes-that-shape-shift-to-fly-electrically","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/designing-airplanes-that-shape-shift-to-fly-electrically\/","title":{"rendered":"Designing Airplanes That Shape Shift to Fly Electrically"},"content":{"rendered":"

Dr. Brien Seeley has a dream, often repeated in this blog, of bringing pocket airparks into our neighborhoods.\u00a0 But the ideal of commuting by small two-seat aircraft and alleviating the crushing gridlock on our highways can only be realized with aircraft that are quiet, able to land and take off within a football field (much like ultralights), and yet cruise at up to 200 miles per hour (much like high-performance lightplanes).\u00a0 This amalgamation of Quicksilver and Lancair might seem unlikely, but Dan Raymer showed attendees at this year\u2019s Electric Aircraft Symposium a possible solution to the dichotomy.<\/p>\n

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Dr. Dan Raymer explains aeronautical shape shifting to this year’s Electric Aircraft Symposium<\/p><\/div>\n

Raymer, head of Conceptual Research Corporation<\/a> and author of Aircraft Design: A Conceptual Approach<\/i>,\u00a0and Dan Raymer’s Simplified Aircraft Design for Homebuilders<\/i>, is an internationally-recognized expert in RDS, or robust design strategies.\u00a0 RDS is defined as a systematic approach to finding optimum values of design factors which result in economical designs with low variability.\u00a0 As a recognized expert in this area, Raymer brought his insights and computerized design skills into play to meet Dr. Seeley\u2019s challenge \u2013 all within a two-day deadline for his evening presentation, his second of the day.<\/p>\n

A morphing airplane can change its external shape in flight, achieving previously unattainable efficiency, according to Dr. Raymer.\u00a0 Making this happen can include using mechanical pivots and actuators, stretching flexible skin that can provide smooth contours over a pivoting frame.<\/p>\n

One form of this, the telescoping wing, shows up in a November 1939 Popular Science article.<\/p>\n

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November 1939 Popular Science envisioned a different form of telescoping wing<\/p><\/div>\n

Later designers would actually build a mechanically-actuated telescoping wing on the Akaflieg Stuttgart FS29, which used a long circumferential belt to extend and retract outer wing panels over the inner panels.\u00a0 With outer panels pulled in, spoilers were covered and could not be used, but the reduced span of 13.3 meters (43.63 feet) was intended for fast inter-thermal cruising and the longer span of 19 meters (62.34 feet) for circling in thermals, landings and takeoffs.<\/p>\n

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Akaflieg Stuttgart’s FS29 telescoping wing sailplane, built in 1975<\/p><\/div>\n

Newer technologies have provided us with shape memory polymers, alloys, and piezoelectric actuators, and with the proper skin, could produce variable shapes tailored to the exact aerodynamic needs of the moment, as shown in the NASA video below.<\/p>\n