@inbook{ca790e3340a247c39153d199e8d9af19,

title = "Experiment and Numerical Analysis of a Rotating Hollow Cylinder in Free Flight",

abstract = "The present purpose is to reveal the mechanism of a flying pipe from an aerodynamic point of view. At first, we conduct field observations of a flying pipe using a pair of high-speed video cameras, together with three-dimensional motion analyses. In addition, we conduct numerical analyses by a finite difference method based on the MAC scheme. As a result, the observed orbit is approximated to be not an obvious parabolic curve but rather a straight line, after an initial instable and complicated curve. The stable flight with this approximately-straight orbit suggests the importance of aerodynamics in flying mechanism. More specifically, the model is in an unstable and complicated flight during an initial flight, afterwards becomes in a stable and approximately-straight flight. In the initial instable and complicated flight, the model flies fluctuating its posture upward, downward, left-ward and right-ward. As flight distance increases, the absolute value and the amplitude of moment becomes small to zero. During such a decaying and stabilising process, the gyroscopic effect plays a primary role balancing not angular acceleration of the model but aerodynamic fluid moment. In the stable and approximately-straight flight, the flow in the stable and approximately-straight flight is nearly the velocity-potential one, and accompanies very-small drag force. And, we could ignore the influence of model{\textquoteright}s rotation upon the flow and the orbit. In this context, the model{\textquoteright}s rotation is only to stabilise its posture, and gives negligible contribution upon its aerodynamics.",

keywords = "Experiment, Numerical analysis, Pipe, Rotation, Three dimension",

author = "Yusuke Naito and Romain Montini and Hirochika Tanigawa and Jun Ishimoto and Masami Nakano and Katsuya Hirata",

note = "Funding Information: Acknowledgements Part of the work was carried out under the Collaborative Research Project of the Institute of Fluid Science, Tohoku University. Publisher Copyright: {\textcopyright} 2020, Springer Nature Singapore Pte Ltd.",

year = "2020",

doi = "10.1007/978-981-15-5436-0_70",

language = "English",

series = "Springer Water",

publisher = "Springer Nature",

pages = "923--936",

booktitle = "Springer Water",

address = "United States",

}