抄録
Numerical simulations of a two-dimensional uniform flow past arrays of 50 circular cylinders of uniform diameter D have been performed for solid volume fraction \phi=0.349, 0.196, 0.126, 0.087, and 0.049 at a Reynolds number ReD=U0D/\nu=180, where U0= inflow velocity and \nu= kinematic viscosity. Three types of array configuration, a lattice-type square pattern, a staggered pattern, and a random distribution are adopted. As \phi is increased, the bulk drag coefficient for the array of cylinders tends to decrease and becomes less sensitive to the details of the array configuration. Hydrodynamic force acting on a cylinder in an array can markedly increase or decrease depending on the allocation pattern of the cylinders. The maximum drag force acting on a cylinder is found to reach up to seven times as high as the time average, indicating the importance of the fluctuation properties of hydrodynamic parameters.
