This paper numerically investigates the flow past two circular cylinders of equal diameter arranged in tandem with respect to the incident flow. The upstream cylinder is fixed, and the downstream cylinder is located within the wake interference region for a streamwise center-to-center spacing of L = 5D (D is the cylinder diameter). The downstream cylinder is forced to vibrate transversely in the wake of the upstream cylinder to investigate a regime of wake-induced vibration (WIV) at a Reynolds number of Re=65,000. The non-dimensional vibration amplitude is fixed at A/D=0.15, and the reduced velocity is set to VR=5. The literature has reported that WIV is a phenomenon resulting from the interaction between the incoming wake and the downstream flexible structure, in which the downstream cylinder vibrates significantly over a wide velocity range, and the cross-flow fluid force is not in phase with the body’s motion. The phenomenon of WIV appears combined with a resonant regime, in which the downstream cylinder vibrates at the resonant velocity similar to the vortex-induced vibration (VIV) of a single cylinder. The results show that the individual resonant regime is captured for both surfaces without roughness effects. The main contribution of this paper is to demonstrate that the roughness effect variation of the downstream cylinder surface desynchronizes the WIV regime and simultaneously promotes synchronization through the emergence of harmonic frequencies, indicating competition between VIV and WIV.
Filho et al. (2026) studied this question.