Numerical Investigation on the Flow-Induced Oscillation of Two Elastic Circular Cylinders in Tandem

The vortex-induced vibration of two elastic cylinders in tandem has been numerically simulated based on the Galerkin finite element method and dynamic mesh technique. Influences of the reduced velocity to the amplitude of vibration displacement of the cylinders was investigated, with cylinder spacing of L/D = 5 and a Reynolds number of 1,000. In the simulation, several classic vortex-induced vibration modes have been obtained, such as beat vibration and resonance. It was found that vortices shed periodically from both the upstream and downstream cylinders. The downstream cylinder undergoes larger amplitude of oscillations in both transverse and streamwise directions than those of the upstream cylinder. Variations in the maximum amplitudes of the oscillation displacement were found to agree with the “three-branch” model.