3D simulations of hydrodynamic drag on a nonhomogeneously structured permeable sphere and advective flow thereof

Abstract

The influence of the structure of a permeable sphere on the flow field and the hydrodynamic drag acting on it are investigated theoretically under the conditions of low to medium large Reynolds number. The anisotropic nature of the permeability of the sphere is taken into account by considering a three-dimensional permeability model. We show that although the permeability in the main flow direction dominates, the permeability in the other directions cannot be neglected. If Reynolds number is small, the larger the permeability in the main flow direction the more significant the influence of the permeability in the other directions. If Reynolds number takes a medium large value, the influence of the permeability in the other directions may decrease if the permeability in the main flow direction is sufficiently large. Depending on the levels of Reynolds number and the permeability, the extent of that influence can be on the order of 10%.