抄録
The present study investigates the motion of two or three rigid spheres settling in an incompressible viscous fluid bounded by a vertical circular cylinder both theoretically and experimentally. In our experiment the ratio of the particle radius a to the cylinder radius L is 0.0142 and the particle Reynolds number(Re=av_z/v) is in the range of 0.140-0.156. Here, v_z is the axial velocity of the sphere and v is the kinematic viscosity of fluid. The cylinder Reynolds number (R_L=Lv_z/v) is finite. The velocities of the spheres were obtained experimentally and theoretically taking into account of the first-order inertial effects of boundaries. Method of matched asymptotic expansions was used.
