Decomposition of fluid forcing and phase synchronisation for in-line vortex-induced vibration of a circular cylinder

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)


We present a decomposition of the streamwise fluid force for in-line vortex-induced vibration (VIV) to provide insight into how the wake drag acts as a driving force in fluid-structure interaction. This force decomposition is an extension of that proposed in the recent work of Konstantinidis et al. (J. Fluid Mech., vol. 907, 2021, p. A34), and is applied to and validated by our experiments examining a circular cylinder freely vibrating in line with the free stream. It is revealed from the decomposition and linear analysis that two regimes of significant vibration are in phase synchronisation, while they are separated by a desynchronised regime marked by competition between non-stationary frequency responses of the cylinder vibration and the vortex shedding. Of interest, such a near-resonance desynchronisation regime is not seen in the transverse vibration case.

Original languageEnglish
Article numberR4
Number of pages16
JournalJournal of Fluid Mechanics
Publication statusPublished - 25 Jun 2022


  • flow-structure interactions
  • vortex dynamics
  • wakes

Cite this