An experimental study on flow over two finite wall-mounted square cylinders in a staggered arrangement

Wind tunnel measurement is conducted over two finite wall-mounted square cylinders in a staggered arrangement for various normalized cylinder distance (P* = P-s/d, where d is the cylinders width). For all experiments, two identical square cylinders with an aspect ratio of 7 are positioned on a line with a staggered angle of 45 degrees relative to the incoming flow direction. The mean pressure distribution on the surfaces of the cylinders, aerodynamic force coefficients and Strouhal numbers are obtained at a Reynolds number Re-d = 6 x 10(4) for 1.42 <= P* <= 5.7. Two flow regimes namely single-body (P* <= 2.1) and modulated-periodic (2.8 <= P* <= 5.7) are identified. The flow is also visualized using the smoke methods at P* = 4 to provide further verification on the modulated-periodic flow patterns. Both cylinders for the single-body regime shed vortices with the same frequencies, whereas the downstream cylinder in the modulated-periodic one represents three dominant frequencies in the spectral analysis. It is also observed that the downstream cylinder experiences a higher drag for P* >= 4.2.