Hydrodynamic Damping on Flexible Cylinders in Sheared Flow

Abstract

The role of hydrodynamic sources of damping in regulating the flowinduced vibration response of flexible cylinders has frequently been a source of disagreement between investigators in the field. A hydrodynamic damping model is proposed in this paper for finite length cylinders and for cables, which effectively behave as if they were of infinite length. Measured and predicted damping for a strumming cable in a sheared flow are presented. The experimental results are from a flow‐induced vibration experiment conducted in a mill canal with a width of 58 ft (17.7 m). Variable headgates allowed a controllable horizontal shear to be produced. Hydrodynamic damping is shown to be one to two orders of magnitude more important than structural damping in sheared flow conditions.