VIV response of a flexible cylinder with varied coverage by buoyancy elements and helical strakes

An investigation into the hydrodynamics of a flexible riser undergoing vortex-induced vibration

“…Therefore, the FBG strain sensors would not affect the flow around the vibrating riser and the vibration characteristics of the flexible riser. As a mature technology, FBG strain sensor techniques have been successfully used in many VIV model tests of flexible risers Fang et al, 2014;Li et al, 2011;Wang et al, 2014). Four FBG strain sensors were placed on 4 points of the opposite sides of a cross section denoted as CF1, CF2, IL1 and IL2, as shown in Fig.…”

Experimental study of the effects of surface roughness on the vortex-induced vibration response of a flexible cylinder

“…The VIV of the structure is one of the key issues in cylinder design. This is because VIV increases the dynamic load on the cylinder and may cause failure or accelerate fatigue of the cylinder, and the issue of the VIV load and corresponding fatigue damage has been studied by many researchers over the last decade (e.g., Fu et al, 2011Fu et al, , 2013Wang et al, 2014;Fang et al, 2014;Wang et al, 2015). When the vortex-shedding frequency approaches one of the natural frequencies of the cylinder, it departs from the Strouhal frequency and begins to follow the natural frequency; this is known as the "lock-in" phenomenon.…”

VIV response of a long flexible riser fitted with strakes in uniform and linearly sheared currents

“…The problem caused by vortex-induced vibration (VIV) has led to a large number of experimental and numerical studies [1][2][3][4][5][6][7][8][9][10][11]. When the vortex shedding frequency is close to the structural frequency, the lock-in (synchronisation) phenomenon occurs, and a riser may experience great fatigue damage induced by a high oscillated vibration amplitude, which should be suppressed.…”