| Summary: | 碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 103 === According to Lissaman and Shollenberger’s article published in Science in 1970, birds fly in formation to reduce the overall energy expenditure for flight. Thus this work adopted the same principle of flight formation to flapping micro-air-vehicles (MAVs) to save energy. Two experiments are described herein. Firstly, a rigid frame housing three flapping MAVs was made and a tethered flight of it around a fixed suspension point was performed to evaluate the cruise performance of the MAV formation and check for energy saving by monitoring the endurance against a known reference value. Due to the intrinsic instabilities of the MAVs, lack of data consistency about in power saving in formation flight concludes less promising results from the 1st experiment. In the second experiment, a jig housing three flapping MAVs was subject to a wind tunnel test at the Wind Engineering Center of Tamkang University. The aerodynamic force evaluation of the MAV formation was done. The tests were performed under different wind speeds, and angle of attacks, and the lift and thrust force produced by the MAVs was measured via a force gauge. Due to the mechanical vibrations from the jig itself and the wind tunnel structure, interpretation of the complicated lift/thrust data was processed by the help of Fast Fourier Transform. From the preliminary examination, it is found that at 3 m/s, 10˚ angle of attack, the performance was the best to save power up to 1.2W. When compared to the real birds flying in a formation, the energy saving of flapping MAVs may be further improved by replicating the dynamic adjustments of frequency, phase change and separation among neighboring MAVs, to obtain best energy-saving results in the future.
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