Numerical Investigation of Vortex Induced Vibration of Rotating Circular Cylinder in Stream Wise Direction Subject to Oscillatory Flow

Abstract

Vortex-induced vibration (VIV) is a phenomenon that occurs when cylindrical structures are subjected to fluid flow. This phenomenon has significant implications in various engineering fields. One notable example is its impact on the offshore riser tubes dynamics used for extracting seabed oil from deep water conditions, where depths of water can reach at 3000 m. Understanding VIV is crucial for the design of such riser systems. Moreover, VIV plays a vital role in other engineering applications at offshore, including mooring lines for offshore floating wind turbines, underwater pipelines, and flexible slender piping’s. When underwater structures exposed to marine currents are susceptible to VIV arises by the oscillatory forces generated due to vortex shedding flow dynamics. This study specifically focuses on investigating the VIV of rotating cylinder in direction stream wise subjected to oscillatory flows. In that study the flow-induced vibration around the rotating cylinder is examined using numerical simulations of two-dimensional. Fluid flow around cylinder is analysed using “Arbitrary Langrangian-Eulerian (ALE) scheme along with Petrov-Galerkin (P-G) Finite Element” method in which fluid structure interactions were deeply examined, along with flow behaviour, ratio of amplitudes and vortex shedding patterns were analysed. The proposed investigation is carried out at 150 Reynolds number with 2 mass ratio and zero damping ratio. Oscillatory flow condition is modelled in numerical simulation using two Kuelegan carpenter numbers, KC=05 and KC=10, with broad range of reduced velocities from 1-20 selected. This research study examines the rotation effects on the flow around on elastically mounting rotating cylinder when flow direction is stream-wise. It is observed during the course of cylinder, along with the KC number and Vr, significantly affects the amplitude of vibration. Cylinder rotations rate is defined by α = ωD/2U where ω is angular velocity of the cylinder. It is kept in a broad range of α= (0.2,0.3,0.4,0.5,0.6,0.7,0.9 & 1) to analyse the cylinder behaviour in oscillatory flow. It was found that the amplitude response of cylinder displacement is directly linked with cylinders’ rotation rate. The peak amplitude response for this present study would occur at the lock-in regime where cylinder vibration approaches to the oscillatory flow frequency. Furthermore, this research includes a comprehensive examination of flow structure to enhance the understanding of the rotational cylinder's underlying physics. The research concluded that when rotation rate increases it would yield rise in amplitude response of cylinder displacement and lock-in regime