An Investigation of a Fundamental Mechanism Controlling Interaction Between Sheared Fluid FLow and Slender Cylinders

点击翻译按钮获取中文摘要

The mechanism controlling vortex-induced motion of marine cables and tethers is of great interest to those who work in the ocean. In almost all marine applications, the fluid flow, which induces themotion, is sheared due to local current variations or is effectively sheared due to curvature of the cable. Shear flow causes the amplitude response of a tow cable to be modulated by a traveling wave. The basic mechanism affecting the formation ofamplitude-modulated traveling waves in a tether subjected to a shear flow will be investigated. Experiments will be performed on a cylinder that is forced to oscillate with a modulated motion, measuring simultaneously the motion of the cylinder, the forces acting on the cylinder, and the amplitude and phase of the fluid forces. One application of such information is in the prediction of the forces on long cables. The experimental will include numerical calculations of two-dimensional flow around a cylinder that is forced to oscillate with amplitude-modulated motion. The coupling of experimental measurements and numerical calculations should lead to an improved understanding of how shear flows and slender cylinders interact.