Growth and Coexistence of Structural and Lift Force Modes in Vortex-Induced Vibration of a Flexible Riser

This study addresses the vortex-induced vibration of a flexible riser pipe. The primary purpose is to determine the fluid–structure interaction mechanism for the modal growth of structural and lift force modes formed along the vibrating riser, and to obtain the fundamental relationship between lift force and elasticity. To this end, a linear theory representing the essence of the vibration mechanics is described, and the mechanical properties involved in the theory are examined by performing eigenvalue analysis. In this theory, the fluid–structure interaction is shown to be mainly governed by spatial correlations among a vertical profile of flow velocities and structural eigenmode functions. The presence of shear induces growth of one or more structural modes, depending on the strength of the shear, and energy necessary for the structural mode growth is supplied from different lift force modes as well as the same mode of lift force. The dominance of multiple frequency components can be explained by differences in growth rate among prominent growing modes.

Language

  • English

Media Info

Subject/Index Terms

  • TRT Terms: Riser pipe; Vibration; Vortices
  • Subject Areas: Hydraulics and Hydrology; Marine Transportation; Pipelines; Vehicles and Equipment;

Filing Info

  • Accession Number: 01691699
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 28 2019 5:11PM