Fully Turbulent Vortex-Induced Vibration on a Cylinder Structure With a Nonlinear Energy Sink Absorber

Abstract The fully turbulent vortex induced vibration (VIV) suppression of a circular cylinder through a nonlinear energy sink (NES) having linear damping and nonlinear cubic stiffness is investigated numerically. The computational fluid dynamics (CFD) method is carried out to calculate the fluid field, while a fourth-order Runge-Kutta method is used to calculating the nonlinear structure dynamics of flow-cylinder-NES coupled system. The fluid-structure interaction (FSI) model is validated against VIV experimental data for a cylinder in a uniform flow. The simulation results show that placing an NES structure with suitable parameters inside of the cylinder structure achieves a good VIV amplitudes’ suppression effect and narrows the “lock-in” region.

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Vortex-Induced Vibration of a Sprung Rigid Circular Cylinder Augmented With a Nonlinear Energy Sink

Volume 1: 24th Conference on Mechanical Vibration and Noise, Parts A and B ◽

10.1115/detc2012-71100 ◽

2012 ◽

Author(s):

Ravi Kumar R. Tumkur ◽

Ramon Calderer ◽

Arif Masud ◽

Lawrence A. Bergman ◽

Alexander F. Vakakis ◽

...

Keyword(s):

Circular Cylinder ◽

Stokes Equations ◽

Computational Study ◽

Coupled System ◽

Nonlinear Energy Sink ◽

Small Mass ◽

Limit Cycle Oscillation ◽

Vortex Induced Vibration ◽

Energy Sink ◽

Nonlinear Energy

We study the nonlinear fluid-structure interaction of an elastically supported rigid circular cylinder in a laminar flow. Periodic shedding of counter-rotating vortices from either side of the cylinder results in vortex-induced vibration of the cylinder. We demonstrate the passive suppression of the limit cycle oscillation (LCO) of the cylinder with the use of an essentially nonlinear element, the nonlinear energy sink (NES). The computational study is performed at a Reynolds number (Re) of 100; Re is defined based on the cylinder diameter and inlet velocity. The variational multiscale residual-based stabilized finite-element method is used to compute approximate solutions of the incompressible Navier-Stokes equations. The NES is comprised of a small mass, an essentially nonlinear spring, and a linear damper. With appropriate values for the NES parameters, the coupled system of flow-cylinder-NES exhibits resonant interactions, resulting in targeted energy transfer (TET) from the flow via the cylinder to the NES, where the energy is dissipated by the linear damper. The NES interacts with the fluid via the cylinder by altering the phase relation between the lift force and the cylinder displacement; this brings about significant reduction in the LCO amplitude of the cylinder for several set of values of the NES parameters.

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Vibration Suppression for Beam-Like Repeating Lattice Structure Based on Equivalent Model by a Nonlinear Energy Sink

Mathematical Problems in Engineering ◽

10.1155/2021/6659598 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Gen Liu ◽

Gongfa Chen ◽

Fangsen Cui

Keyword(s):

Vibration Suppression ◽

Lattice Structure ◽

Vibration Reduction ◽

Coupled System ◽

Nonlinear Energy Sink ◽

Equivalent Model ◽

External Excitation ◽

Suppression Effect ◽

Energy Sink ◽

Nonlinear Energy

Based on the fully deployed space beam-like truss, the vibration reduction of the lattice structure is studied by using the local NES (nonlinear energy sink) attachment in this paper. The beam-like lattice structure is modeled as an equivalent linear continuous system (a finite length beam) by the equivalent method and validated with the finite element results. The dynamic vibration equations for the equivalent cantilever beam are established and the governing equations for the equivalent beam with NES are approximated by the Galerkin method. The displacement responses of the beam with and without NES attached under shock excitation are obtained. With NES at different positions, the amplitude responses of the coupled system under the external excitation at different positions are calculated to evaluate the suppression effect of the NES attachment to the structure. And with different masses of the NES, the amplitude responses of the coupled structure subject to the external excitation at different positions are also investigated to get the influence of the mass of the NES attachment to the vibration reduction. It can be seen from the results that the NES attachment can attenuate the response of the beam-like truss under transient excitation efficiently. And with the mass of NES attachment increasing, the vibration amplitude of the coupled system declines more rapidly, and the energy consumption efficiency of the NES attachment is higher. Moreover, the attenuation effect of the NES with different masses is experimentally analyzed. The experimental results are in good accord with the theoretical calculation.

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