Aerodynamic characteristics and flow field characteristics of rigid and forced-vibration square cylinders in turbulent flow
Zengshun Chen, Zheyu Zhang, Yemeng Xu, Yunfei Fu, Likai Zhang, Qiqi Wu
Abstract
Fluid–structure interaction (FSI) is a fundamental problem in fluid mechanics, which is prevalent across diverse practical engineering applications and has a significant impact on the safety and reliability of structures. In this study, large eddy simulation is employed to perform numerical simulations of a three-dimensional finite-length isolated square cylinder under varying incoming flow velocities and prescribed crosswind vibration states in a turbulent inflow. This configuration, combining finite-length structure, structural vibration, and turbulent flow, is designed to closely mimic realistic wind-resistant conditions encountered in engineering practice. Based on the mean pressure coefficients and flow field phenomenology, the FSI mechanisms are systematically examined in two distinct regimes. Within the vortex-induced vibration (VIV) velocity range, structural vibration markedly modifies the behavior of the separated shear layers, leading to significant changes in the distributions of mean pressure coefficients, wake topology, vortex shedding, and three-dimensional vortex structures compared with the rigid square cylinder. At high wind velocity, however, the influence of structural vibration becomes weak and the FSI response is instead governed predominantly by the incoming flow, and the flow field exhibits characteristics that are different from those in the VIV regime. This study is expected to deepen understanding of how both structural motion and inflow conditions jointly control the global FSI response under this realistic configuration, and to provide a reference for subsequent related studies.