Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Flow-Induced Vibration of a Long Flexible Sheet in Tangential Flow
P. Šidlof, J. Kolář, P. Peukert
Abstract:
During certain stages of the offset printing process, the paper sheet is conveyed by the blower air. Vibration and acoustic measurements confirmed that under certain circumstances the sheet undergoes flow-induced vibration with signifficant amplitudes, generating a serious noise source at the same frequency. In order to understand the fluid-structure interaction between the flexible paper sheet and air exiting the nozzles, and to assess the conditions when unstable paper vibration with large amplitudes is possible, a simplified analytical model was developed. The paper sheet, modeled as a flexible 1D chain, is fully coupled to quasi-1D inviscid flow. Under the assumption of small deflections, the coupled equations can be analytically solved in frequency domain, yielding complex eigenfrequencies of the system. For a given flow velocity (corresponding to a specific air pressure setting), the real and imaginary part of the eigenfrequency determines whether the system is stable or unstable.
Keywords:
fluid-structure interaction, flutter, offset printing systems

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2018.034

In Proceedings Topical Problems of Fluid Mechanics 2018, Prague, 2018 Edited by David Šimurda and Tomáš Bodnár, pp. 251-256 ISBN 978-80-87012-65-9 (Print) ISSN 2336-5781 (Print)