This study investigates the flow hydrodynamics around two cylinders by comparing large eddy simulation (LES) and Reynolds averaged Navier-Stokes (RANS) models. The computational flow domain includes streamwise, spanwise, and vertical directions, defined over a 26D × 20D × 3D space. Numerical simulations are carried out for three gap ratios (S/D = 2, 3, and 4) and four different Reynolds numbers (Re = 253, 12,674, 25,348, and 126,746). The effects of Reynolds number and gap spacing on the formation of streamlines, wake structures, and horseshoe vortices are examined. At low Reynolds numbers and narrow gaps, interactions between the flow and cylinders result in significant deviations in flow behavior compared to that around a single isolated cylinder. In contrast, at higher Reynolds numbers and wider gaps, the influence of cylinder spacing diminishes, and the flow characteristics become largely uniform. Overall, LES provides a more accurate representation of flow hydrodynamics compared to RANS, especially in capturing complex vortex structures.