Abstract
Drag force acting on a system of densely packed particles is common issue for fluidization of particles where the bulk motion is induced by the drag action of fluid flow. The discrete element method based on Euler-Lagrange descriptions can provide realistic particle-fluid and particle-particle interactions but are unable to simulate the flow phenomena in the space smaller than a particle size. However, the study of flow in such scale is crucial for the drag force analysis. Accordingly, the present study applied the immersed boundary method which is one of the direct numerical simulations, to investigate the drag force by simulating the flow around each particle. Here, particles were positioned with the different kinds of spatial arrangements in order to represent the different degree of voidages, and the flow around these particles.
