著者

廣明 慶一 渡辺 昌宏

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.858, pp.17-00416-17-00416, 2018 (Released:2018-02-25)

参考文献数

23

被引用文献数

1

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An instability mechanism of flutter generated on a rectangular flexible sheet in an axial fluid flow is investigated through the energy-transfer quantifications. The work done by unsteady fluid force acting on the fluttering sheet surface is calculated based on a three dimensional flutter analysis utilized the Doublet-point method and finite element method. Then the work done by fluid force is divided to three terms caused by fluid added mass, damping and stiffness by applying Roger's approximation, and influence of each term on stability is clarified. As a result, it is clarified that the work caused by fluid added stiffness is dominant for excitation of flutter. Lastly, the influence of the work caused by interaction of natural vibration modes of the sheet which are dominant for flutter on stability is investigated, and the instability mechanism of flutter is discussed.

著者

廣明 慶一 河合 伸人 渡辺 昌宏

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00025-17-00025, 2017 (Released:2017-08-25)

参考文献数

20

被引用文献数

2

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This paper presents a three dimensional flutter analysis of slender webs under tension in cross flow. In the flutter analysis, Doublet-point method based on the unsteady lifting surface theory is used to calculate unsteady fluid force acting on the web surface. The equation of motion of the web under tension is derived by using the finite element method. Flutter velocity, frequency and mode are predicted through the root locus of the flutter determinant of the system with changing flow velocity. The theoretical results are compared to experimental results to confirm validity. Moreover, the local work done by the fluid force acting on the web surface is calculated, and instability mechanism is discussed. Lastly, unified empirical equation of flutter velocities for several parameters of webs is proposed.