A Study of Forces and Vortex Patterns Around a Vortex-excited Vibrating Cylinder in Planar Oscillatory Flow

Abstract

This paper describes an experimental investigation into the non-linear vortex-excited vibration of a cylinder in plannar oscillatory flow with emphasis being placed on the fluid-structure interaction. The experiments were carried out using a water tank which has an internal dimension of 1.0m long, 0.5m wide and 0.5m deep, and is oscillated in true harmonic horizontal motion. The deferences between the vortex patterns around the vortex-excited cylinder in rezonace condition and those around the rigidly mounted cylinder are clarified in the range of Keulegan-Carpenter number 5 to 8.4 by using the flow visualization. In this range of KC number, the amplification of the fluid forces acting on a vortex-excited. cylinder are large.