Wang, H.; Zhai, Q.; Hou, J., and Xia, L., 2018. Numerical investigation on the vortex-induced vibration of a flexible plate behind a circular cylinder. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1326–1330. Coconut Creek (Florida), ISSN 0749-0208.
Vortex-induced vibration (VIV) of piezoelectric cantilever plate can convert the kinetic energy of flow into electricity effectively, and this technique has become a new research focus in the field of ocean energy harvesting and utilization over the past few years. It is known that the lock-in effect existing in VIV phenomenon can significantly broaden the structural resonance region, and improve the flow energy harvesting efficiency. The present study aims to investigate the VIV responses of a flexible plate located in the wake of a circular cylinder using a strongly coupled finite element model. Numerical simulations are conducted for two typical plate lengths (L/D = 2.0, 4.0; D is the cylinder diameter) within a wide range of gap spacings 0.5 ≤ S/D ≤ 4.0. Generally, the results show that with the increase of gap spacing, the gap flow pattern changes from vortex suppression state to vortex shedding state. For L/D = 2.0, “soft” lock-in occurs all through the examined gap spacing range, among which the plate vibrates with significant amplitude. For L/D = 4.0, the lock-in region is found to be S/D ≤ 2.0, characterized by large-amplitude resonance and vortex suppression in the gap; however, with the appearance of the gap vortex shedding, the vibration becomes negligible at S/D ≥ 2.5. The pressure distribution of fluid along the upper and lower sides of the plate is analyzed to reveal the dynamic coupling mechanism between the flow and plate. This study will provide useful theoretical reference for optimum design of the VIV energy harvesting device.