Aerodynamics of hovering dragonfly flight

• Main Authors: Kao, Yu Kai, 高于凱
• Other Authors: Lee, Shong Leih
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/08757675122858303395

碩士 === 國立清華大學 === 動力機械工程學系 === 103 === Dragonflies’ flying ability is extraordinary, which attracts many scholars to dig into. Among the way of dragonfly flight, hovering is the most special topic. If we can analyze the trajectory of a dragonfly’s wings and its flow field, it will be helpful for bionic research and designing flying machine. To study the hovering dragonfly fight, we make use of the photos of the dragonfly (Aeschna juncea), which are taken by high-speed camera at 80 frames s-1 with the dragonfly wingbeat frequency at 37Hz. We build a three-dimensional (3D) model of the wings, and then use the model to measure the kinematic parameters varying from the photos. Next, by transforming three-dimensional model (3D) from two-dimensional model (2D), we can describe the trajectory of mid-span chord in 2D flow field. Then, by numerical method, we simulate the velocity and pressure distribution when the dragonfly is hovering, which help us to get the lift and the drag generated by wingbeat. Also, we simulate the velocity and pressure distribution at single-wing movement to study the difference movement of single wing from the fore- and hindwings.