Imperial College London

ProfessorSpencerSherwin

Faculty of EngineeringDepartment of Aeronautics

Professor of Computational Fluid Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 5052s.sherwin Website

 
 
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Location

 

313BCity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Assi:2013:10.1017/jfm.2012.606,
author = {Assi, GRS and Bearman, PW and Carmo, BS and Meneghini, JR and Sherwin, SJ and Willden, RHJ},
doi = {10.1017/jfm.2012.606},
journal = {JOURNAL OF FLUID MECHANICS},
pages = {210--245},
title = {The role of wake stiffness on the wake-induced vibration of the downstream cylinder of a tandem pair},
url = {http://dx.doi.org/10.1017/jfm.2012.606},
volume = {718},
year = {2013}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - When a pair of tandem cylinders is immersed in a flow the downstream cylinder can be excited into wake-induced vibrations (WIV) due to the interaction with vortices coming from the upstream cylinder. Assi, Bearman & Meneghini (J. Fluid Mech., vol. 661, 2010, pp. 365–401) concluded that the WIV excitation mechanism has its origin in the unsteady vortex–structure interaction encountered by the cylinder as it oscillates across the wake. In the present paper we investigate how the cylinder responds to that excitation, characterising the amplitude and frequency of response and its dependency on other parameters of the system. We introduce the concept of wake stiffness, a fluid dynamic effect that can be associated, to a first approximation, with a linear spring with stiffness proportional to Re and to the steady lift force occurring for staggered cylinders. By a series of experiments with a cylinder mounted on a base without springs we verify that such wake stiffness is not only strong enough to sustain oscillatory motion, but can also dominate over the structural stiffness of the system. We conclude that while unsteady vortex–structure interactions provide the energy input to sustain the vibrations, it is the wake stiffness phenomenon that defines the character of the WIV response.
AU - Assi,GRS
AU - Bearman,PW
AU - Carmo,BS
AU - Meneghini,JR
AU - Sherwin,SJ
AU - Willden,RHJ
DO - 10.1017/jfm.2012.606
EP - 245
PY - 2013///
SN - 0022-1120
SP - 210
TI - The role of wake stiffness on the wake-induced vibration of the downstream cylinder of a tandem pair
T2 - JOURNAL OF FLUID MECHANICS
UR - http://dx.doi.org/10.1017/jfm.2012.606
UR - http://www2.imperial.ac.uk/ssherw/spectralhp/papers/JFM-AlBeCaMeShWi-13.pdf
UR - http://hdl.handle.net/10044/1/15364
VL - 718
ER -