Back to Search Start Over

Research on the Flow-Induced Vibration of Cylindrical Structures Using Lagrangian-Based Dynamic Mode Decomposition

Authors :
Xueji Shi
Zhongxiang Liu
Tong Guo
Wanjin Li
Zhiwei Niu
Feng Ling
Source :
Journal of Marine Science and Engineering, Vol 12, Iss 8, p 1378 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

An oscillating flow past a structure represents a complex, high-dimensional, and nonlinear flow phenomenon, which can lead to the failure of structures due to material fatigue or constraint relaxation. In order to better understand flow-induced vibration (FIV) and coupled flow fields, a numerical simulation of a two-degrees-of-freedom FIV in a cylinder was conducted. Based on the Lagrangian-based dynamic mode decomposition (L-DMD) method, the vorticity field and motion characteristics of a cylinder were decomposed, reconstructed, and predicted. A comparison was made to the traditional Eulerian-based dynamic mode decomposition (E-DMD) method. The research results show that the first-order mode in the stable phase represents the mean flow field, showcasing the slander tail vortex structure during the vortex-shedding period and the average displacement in the in-line direction. The second mode predominantly captures the crossflow displacement, with a frequency of approximately 0.43 Hz, closely matching the corresponding frequency observed in the CFD results. The higher dominant modes mainly capture outward-spreading, smaller-scale vortex structures with detail displacement characteristics. The motion of the cylinder in the in-line direction was accompanied by symmetric vortex structures, while the motion of the cylinder in the crossflow direction was associated with anti-symmetric vortex structures. Additionally, crossflow displacement will cause a symmetrical vortex structure that spreads laterally along the axis behind the cylinder. Finally, when compared with E-DMD, the L-DMD method demonstrates a notable advantage in analyzing the nonlinear characteristics of FIV.

Details

Language :
English
ISSN :
20771312
Volume :
12
Issue :
8
Database :
Directory of Open Access Journals
Journal :
Journal of Marine Science and Engineering
Publication Type :
Academic Journal
Accession number :
edsdoj.621b453153c64911a584dffb349a7c00
Document Type :
article
Full Text :
https://doi.org/10.3390/jmse12081378