Flow interference of two side-by-side square cylinders using IB-LBM – Effect of corner radius

In this study, a two-dimensional Immersed Boundary Lattice Boltzmann Method (IB-LBM) is employed to investigate computationally effect of flow past a pair of square cylinders in side-by-side arrangement at Re=100, for various corner radii. Numerical simulations were performed simultaneously by varying center to center distance between two cylinders (1.5–5.0 D) in the transverse direction and by changing the corner radius (R) from R/D = 0.0 (square) to 0.5 (circular) with 0.1 increment. Aerodynamic characteristics, including the lift and drag coefficients, were quantitatively calculated and compared with each other. Vorticity contours were used as visualization aids to understand the wake pattern and underlying mechanism. The results indicate different features in lift and drag time histories and in wake patterns for a selected range. The numerical results reveal that the flow characteristics and vortex shedding depend significantly on the corner radius and gap spacing. A square cylinder exhibited the maximum average drag value, and the inverse was observed in the case of a circular cylinder. Furthermore, aerodynamic forces were reduced by rounding the corner radius.