Analysis of the cross-flow features around two side-by-side rectangular cylinders

This study employs the lattice Boltzmann method (LBM) to numerically analyze the fluid flow around two side-by-side rectangular cylinders with an aspect ratio (AR) of 3:2. The gap spacing (G) between the cylinders is taken in the range 0–10 and the Reynolds number (Re) is fixed at 200. The numerical outcomes depict a strong correlation between flow patterns, force variations, gap spacing, and aspect ratio. Among these parameters, the latter ones strongly influence the flow-induced drag, lift, and pressure. The mean drag coefficient (CD mean ), Strouhal number (St), and root-mean-square values of force coefficients exhibit rapid variations under the impact of these parameters for both cylinders. The observed outcomes further indicate that flow structures in the wake vary with changes in gap spacing. Five separate patterns of wake flow are detected, depending on varying gap spacing. These patterns include isolated bluff-body flow, flip-flopping flow, non-synchronized flow, modulated synchronized flow, and synchronized flow. • The impact of gap ratio on two side-by-side rectangular 3:2 cylinders has been investigated using lattice Boltzmann method. • The Reynolds number is fixed at 200 and gap ratios are varied between 0 and 10. • Depending on gap ratio, the flow behind the cylinders is categorized into five different flow patterns. • These patterns include isolated bluff-body, flip-flopping flow, non-synchronized, modulated synchronized and synchronized.