Numerical investigation on flow-induced vibrations of two staggered square cylinders using GPU-IB-LBM

A numerical investigation was conducted using a graphical processing unit for a multicylinder system. The aim was to study the flow dynamics around a pair of identical square cylinders arranged in staggered configurations, with a low Reynolds number of 100. The staggered angle of the downstream cylinder was systematically varied as 0°–45°, while distance between the cylinder centers ranged as 1.5D–5.0D. Both cylinders maintained a consistent mass ratio of 10.0, fixed frequency ratio of 1.0, and fixed natural frequency was chosen to achieve optimal oscillation amplitude. The results of this study highlighted the notable influence of proximity gaps on oscillation response. Moreover, introduction of staggered angles further amplified cylinder oscillation. In scenario involving two square cylinders, an intriguing fluid-induced vibration phenomenon occurred when a proximity gap of 1.5D was combined with a downstream rotational angle of 45°, resulted highest level of oscillation response. The research demonstrated that for smaller proximity gaps and the incorporation of angles, the oscillation positions of cylinders deviated from center. With increase in proximity gaps, oscillation positions converged back towards center. Notably, with widest proximity spacing of 5.0D, oscillation pattern of the upstream cylinder closely resembled that of an individual square cylinder.