Vortex-induced vibrations of three staggered circular cylinders at low Reynolds numbers

Abstract

Vortex-induced vibrations of three staggered circular cylinders are investigated via two-dimensional finite element computations. All the cylinders are of equal diameter (D) and are mounted on elastic supports in both streamwise (x−) and transverse (y−) directions. The two downstream cylinders are placed symmetrically on either side of the upstream body at a streamwise gap of 5D, with the vertical distance between them being 3D. Flow simulations are carried out for Reynolds numbers (Re) in the range of Re = 60-160. Reduced mass (m*) of 10 is considered and the damping is set to zero value. The present investigations show that the upstream cylinder exhibits initial and lower synchronization response modes like an isolated cylinder does at low Re. Whereas for both the downstream cylinders, the upper lock-in branch also appears. The initial and the upper modes are characterized by periodic oscillations, while the lower lock-in branch is associated with nonperiodic vibrations. The 2S mode of vortex shedding is observed in the near wake of all the cylinders for all Re, except for the upper branch corresponding to the downstream bodies. In the upper branch, both the downstream cylinders shed the primary vortices of the P+S mode. For the upstream cylinder, the phase between lift and the transverse displacement exhibits a 180° jump at certain Re in the lower branch. On the other hand, the downstream bodies undergo transverse oscillations in phase with lift in all lock-in modes, while the phase jumps by 180° as the oscillation response reaches the desynchronization regime.

Research on Flow-Induced Vibration and Energy Harvesting of Three Circular Cylinders with Roughness Strips in Tandem

“…Ma et al [38] concluded that the upstream cylinder will influence FIV response of the downstream one and the effect is becoming more dominant as damping increases. It should be pointed that few papers studied the disturbances among multiple cylinders [39,40] and all of those cylinders are stationary. Kim and Bernitsas [41] experimentally studied the FIV of three cylinders in tandem.…”

“…It should be pointed that few papers studied the disturbances among multiple cylinders [39,40] and all of those cylinders are stationary. Kim and Bernitsas [41] experimentally studied the FIV of three cylinders in tandem.…”

Junction flow inside and around three-row cylindrical group on rigid flat surface

“…A large number of works have been carried out for tandem cylindrical structures ( Mahbub Alam and Zhou, 2008 ; Palau-Salvador et al., 2008 ; Ataie-Ashtiani and Aslani-Kordkandi, 2013 ; Kim et al., 2017 ), three-cylinder structures ( Noack et al., 2016 ; Zheng et al., 2016 ; Behara et al., 2017 ; Chen et al., 2018 , 2020a , 2020b ), four cylinders ( Lam et al., 2003 ; Lam and Zou, 2010 ; Tong et al., 2014 ; Yang et al., 2021 ), six or more cylinders ( Takemura and Tanaka, 2007 ; Galan et al., 2019 ). A number of studies have been carried out with large groups of bluff bodies ( Zong and Nepf, 2012 ; Chang et al., 2017 , 2018 , 2020 ; Voskoboinick et al., 2021 ).…”