EFFECTS OF DOMAIN SIZE ON FLOW CHARACTERISTICS IN SIMULATING PERIODIC OBSTACLE FLOW

초록

Effects of computational domain size in simulating of periodic obstacle flow has been investigated for the flow past tube banks. Reynolds number, defined by freestream velocity (U_∞) and cylinder diameter (d), was fixed as 200, and center-to-center distance (P) as 1.5 d. In-line square array and staggered square array were considered. Drag coefficient, lift coefficient and Strouhal number were calculated depending on domain size. Circular cylinders were implemented on a Cartesian grid system by using an immersed boundary method. Boundary condition is periodic in both streamwise and lateral directions. Previous studies in literature often use a square domain with a side length of P, which contains only one cylinder. However, this study reveals that the domain size is improper. Especially, RMS values of flow-induced forces are most sensitive to the domain size.