Generation of the pitch moment during the controlled flight after takeoff of fruitflies

• Published in: PloS one Vol. 12; no. 3; p. e0173481
• Main Authors: Chen, Mao Wei, Wu, Jiang Hao, Sun, Mao
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.03.2017; Public Library of Science (PLoS)
• Subjects: Aerodynamics; Angle of attack; Angular velocity; Animals; Biology and Life Sciences; Biomechanical Phenomena; Body kinematics; Computational fluid dynamics; Computer applications; Correlation analysis; Deviation; Drosophila; Drosophila melanogaster - physiology; Flight; Flight, Animal; Fluid dynamics; Fruit flies (Tephritidae); Fruits; Hydrodynamics; Insect flight; Insects; Kinematics; Medicine and Health Sciences; Physical Sciences; Physiological aspects; Pitch (inclination); Pitching moments; Takeoff
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0173481

In the present paper, the controlled flight of fruitflies after voluntary takeoff is studied. Wing and body kinematics of the insects after takeoff are measured using high-speed video techniques, and the aerodynamic force and moment are calculated by the computational fluid dynamics method based on the measured data. How the control moments are generated is analyzed by correlating the computed moments with the wing kinematics. A fruit-fly has a large pitch-up angular velocity owing to the takeoff jump and the fly controls its body attitude by producing pitching moments. It is found that the pitching moment is produced by changes in both the aerodynamic force and the moment arm. The change in the aerodynamic force is mainly due to the change in angle of attack. The change in the moment arm is mainly due to the change in the mean stroke angle and deviation angle, and the deviation angle plays a more important role than the mean stroke angle in changing the moment arm (note that change in deviation angle implies variation in the position of the aerodynamic stroke plane with respect to the anatomical stroke plane). This is unlike the case of fruitflies correcting pitch perturbations in steady free flight, where they produce pitching moment mainly by changes in mean stroke angle.