Effect of degrees of structural freedom on the flow-induced vibrations of isolated and tandem cylindrical structures

초록

This study aims to numerically investigate the influence of degrees of structural freedom on the flow-induced vibration characteristics of an isolated and tandem cylindrical structures at low Reynolds number. Both the single and tandem cylinders underwent transverse-only (1-DoF) and combined streamwise and transverse (2-DoF) vibrations which are characterized by the mass-spring system. A fluid-structure interaction scheme is formulated using the split-forcing lattice Boltzmann equation for the fluid domain in combination with an immersed boundary solver and equations of rigid body motion for the structural part. The dynamic response of an isolated and tandem structures computed for 1-and 2-DoF cases are similar regarding the lock-in phenomenon and hydrodynamic forces at a relatively large mass ratio. The comparison of vorticity field suggests that an additional degree of freedom has no significant effect on the vortex shedding pattern. Furthermore, in the presence of another identical structure placed in the upstream direction, the downstream structure oscillates with higher amplitudes.

키워드