Numerical simulation of flow induced vibration of two rigidly connected cylinders in different arrangements

The flow induced vibration (FIV) responses of two rigidly connected cylinders at different staggered configurations have been studied numerically. The two cylinders, with an equal diameter of D, can oscillate in both cross-flow (CF) and in-line (IL) directions simultaneously. The center-to-center spacing between the two cylinders has been fixed at 4D. The numerical results demonstrate that as the angle of incidence (α) increases, the wake interference between the two cylinders becomes weak. For α with small values, the FIV responses are dominated by the galloping vibration and the vortex-induced vibration (VIV) simultaneously. However, for α with large values, the FIV responses are obviously dominated by the VIV. As α increases, the maximum vibration amplitude follows a downward trend and the total mean drag coefficient tends to decrease. Furthermore, the vortex shedding flow pattern has apparently different modes for varying α.