Vortex-induced vibrations and waves under shear flow with a wake oscillator model

This paper addresses the interaction of a slender structure and a sheared incident cross-flow. The oscillating wake of the structure is modeled using a distribution of van der Pol oscillators. Elementary configurations are first considered to assess the basic phenomena and structure dynamics allowing to reliably investigate more complex and realistic cases. The scope of the study thus ranges from a forced oscillating cylinder to a tensioned cable. This last configuration is found to experience wave-packets of vortex-induced motion due to a series of local lock-ins. A theoretical analysis is carried-out to predict the wave-packets amplitude and distribution. It is shown to be in reasonable agreement with the results of numerical simulations. This indicates that the system behavior can be described in terms of the local interactions between the wake and the structure only.