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Daniel Raymer with Conceptual Research Corp. |
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Date: July 26, 2004
Time: 9:00am
Location: NASA LaRC, Bldg 1192C, Rm 102
Speaker: Daniel Raymer with Conceptual Research Corp.
Subject: "Morphing Aircraft Study"
Dr. Raymer, author of bestseller Aircraft Design: A Conceptual Approach, will present the results of his company’s USAF/DARPA contracted study of high speed morphing aircraft.
Morphing is especially promising for high-speed flight because of the vast disparity between the optimal wing geometry at high speeds and the optimal wing geometry for subsonic cruise, maneuver, and loiter. This problem is even worse for an aircraft that must perform a normal takeoff and landing, where the wing size required is several times the wing size desired for high-speed flight.
In this study Conceptual Research Corporation (CRC) has defined and assessed air vehicle morphing technologies and concepts with emphasis on applications to high-speed flight. Potential benefits of morphing for high-speed flight were evaluated and suitable morphing concepts were defined. Several morphing approaches were selected for air vehicle design studies, based on notional missions in which morphing could offer substantial improvements in vehicle capabilities. Design layouts were prepared and analyzed, and comparisons to non-morphing alternative designs were made. Also, developmental risks were described and assessed.
Two concepts were defined and analyzed. The first is the foldover tip concept wherein an outer wing panel folds over the top (or bottom) of the main wing and tucks conformally into a pocket cutout on the main wing (see next section for details). For a high-speed aircraft this approach offers a substantial increase in wing area and aspect ratio, ease of mechanization, good aerodynamic contours in both closed and open positions, and minimal change in the aerodynamic center.
The other concept selected for a design study is the telescoping wing. This has been proposed for many decades, and provides the desired increase in wing area and aspect ratio for slow-speed flight. However, mechanization complexity and weight have prevented its usage. These penalties may prove bearable for high-speed flight, where the concept offers the great advantage of completely hiding the outer wing panel from the hot environment.
This study has provided clear evidence that morphing does offer benefits for high-speed aircraft. It allows better optimizing of the wing for the flight at supersonic speeds, and by changing wing geometry, can provide the greater wing area and span needed for efficient cruise and loiter, and for takeoff and landing at reasonable speeds. Results of this study indicate that use of readily attainable morphing technologies can provide roughly a 15% reduction in sized takeoff gross weight for the high-speed UCAV-N mission. For the satellite booster first stage concept, morphing reduces sized takeoff gross weight by as much as 40% for a mission without use of aerial refueling.
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