Vortex-induced Vibration of Two Rigidly Coupled Tandem Cylinders: A Numerical Study

This study explores the intricate mechanical mechanisms underlying vortex-induced vibrations by employing the multi-body force element theory. Numerical simulations are conducted on a 2-DOF rigidly coupled double-cylinder sys-tem, considering a uniform incoming flow with a Reynolds number of Re = 150, a mass ratio of m∗ = 2, a damping ratio of ζ = 0, and an aspect ratio L/D = 4. The vortex force analysis, which based on the force element theory and quantifies the contributions of all fluid elements with non-zero vorticity to the force exerted on the cylinders. The results indicate that the force contribution due to vortex-induced vibrations within the lock-in region differs from that outside of it. Moreover, as the vortex shedding pattern changes, the distribution of the force element components also varies.