Imperial College London
Alternate

Dr. Yongyun Hwang

Faculty of Engineering, Department of Aeronautics

Reader in Fluid Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 5078y.hwang

 
 
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Location

 

337City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Basso:2021:10.1017/jfm.2021.830,
author = {Basso, R and Hwang, Y and Assi, G and Sherwin, S},
doi = {10.1017/jfm.2021.830},
journal = {Journal of Fluid Mechanics},
pages = {1--32},
title = {Instabilities and sensitivities in a flow over a rotationally flexible cylinder with a rigid splitter plate},
url = {http://dx.doi.org/10.1017/jfm.2021.830},
volume = {928},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - This paper investigates the origin of flow-induced instabilities and their sensitivities ina flow over a rotationally flexible circular cylinder with a rigid splitter plate. A linearstability and sensitivity problem is formulated in the Eulerian frame by considering thegeometric nonlinearity arising from the rotational motion of the cylinder which is notpresent in the stationary or purely translating stability methodology. This nonlinearityneeds careful and consistent treatment in the linearised problem particularly whenconsidering the Eulerian frame or reference adopted in this study and not so widelyconsidered. Two types of instabilities arising from the fluid-structure interaction arefound. The first type of the instabilities is the stationary symmetry-breaking mode, whichwas well reported in previous studies. This instability exhibits a strong correlation withthe length of the recirculation zone. A detailed analysis of the instability mode andits sensitivity reveals the importance of the flow near the tip region of the plate for thegeneration and control of this instability mode. The second type is an oscillatory torsionalflapping mode, which has not been well reported. This instability typically emerges whenthe length of the splitter plate is sufficiently long. Unlike the symmetry breaking mode,it is not so closely correlated with the length of the recirculation zone. The sensitivityanalysis however also reveals the crucial role played by the flow near the tip region inthis instability. Finally, it is found that many physical features of this instability arereminiscent of those of the flapping (or flutter instability) observed in a flow over aflexible plate or a flag, suggesting that these instabilities share the same physical origin.
AU  - Basso,R
AU  - Hwang,Y
AU  - Assi,G
AU  - Sherwin,S
DO  - 10.1017/jfm.2021.830
EP  - 32
PY  - 2021///
SN  - 0022-1120
SP  - 1
TI  - Instabilities and sensitivities in a flow over a rotationally flexible cylinder with a rigid splitter plate
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2021.830
UR  - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/instabilities-and-sensitivities-in-a-flow-over-a-rotationally-flexible-cylinder-with-a-rigid-splitter-plate/FFC1B79344122ED67FCBB41C68F534FE
UR  - http://hdl.handle.net/10044/1/91582
VL  - 928
ER  -
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