A STUDY ON INTRODUCTION OF A PERIODIC BOUNDARY CONDITION TO POROUS MEDIA FLOW MODEL

Abstract

 The detail of how to impose the periodic boundary condition to the Immersed Boundary Method (IBM) with the Physical Virtual Model (PVM) for calculating the external force is described and it is derived to be necessary to ensure five cells as the virtual boundary. The validity of the proposed periodic boundary condition was confirmed by flow calculations for a single sphere.In addition, a porous medium consisting of multiple spheres was placed in the computational domain, and the flow through the porous medium was computed with a unidirectional steady flow under the periodic boundary condition. The calculation results showed good agreement with the macroscopic empirical law on the pressure drop. The distributions of vorticity and shear stress in the pore of the porous media and wake are presented. Finally, the spatial gradients of velocity components, which are the dominant factors of occurrence of shear stress, are discussed.