Numerical Simulation of free falling Cylinders using Overset Grid Method

An incompressible and unsteady flow problem in free falling of cylindrical particles was investigated in the intermediate Reynolds Number. Shape of the body that is used in an initial value problem in a vertical channel for the free falling was considered circular, square and rectangular cylinders. Fluid flow was computed by the Navier-Stokes equations for moderate Reynolds numbers. The particles were moved by effect of hydrodynamic, gravity and buoyancy forces. The governing equations for particle included second Newton law and torque were exerted over the particle. The particle-fluid interaction may treat by introducing a fully two dimensional overset grid Scheme. Overset grid Scheme may allow each component of a flow to be treated accurately and efficiently. The amounts of drag coefficients, free falling velocity, angular velocity and deviation for free falling cylinders were obtained for different Reynolds numbers (0.5≤Re50) and then were compared with experimental results. Free falling of two rectangular and square cylinders in different situations were also treated and the results compared with available data in fair agreement.