Flow-Induced Vibration of an Elastically Mounted Cylinder Under the Influence of Downstream Stationary Cylinder

The paper presents numerical investigation of flow-induced vibration of an elastically mounted circular cylinder in proximity of identical downstream stationary cylinder at Reynolds number Re = 100. The problems are solved using in-house code based on Level-Set function-based Immersed Interface method (LS-IIM). The elastically mounted cylinder has mass ratio \(m^{*} = 2.0\) and damping ratio \(\zeta = 0.005\) . The two cylinders are placed in tandem arrangement with varying gap ratios of \(G^{*} = 2.5 - 0.1\) . . Three distinct vibration responses named as vortex-induced vibration (VIV), proximity-induced galloping (PIG), and proximity pressure-induced staggered vibration (PPISV) are observed at larger ( \(G^{*} \ge 1.5\) ), intermediate ( \(G^{*} = 0.5,0.3\) ), and smaller gaps ( \(G^{*} = 0.3, 0.1\) ), respectively. The novel vibration response PPISV is caused by enhanced influence of proximity pressure of downstream cylinder. Similar to galloping, large amplitude A*, low frequency in-phase oscillation occurs in the PIG vibration response. The three vibration responses have distinct flow dynamics occurring in gap, called as flow states and each flow state is discussed in this paper.