  In this paper, two mesh-free CFD solvers for pore-scale fluid flow through
porous media are considered, namely the Lattice Boltzmann Method with the two
relaxation time collision term and the direct Navier-Stokes solver under the
artificial compressibility limit. The porous media is built with a regular
arrangement of spherical grains with variable radii, which allows control of
the porosity. Both solvers use the same h-refined meshless spatial
discretization to adequately capture the underlying geometry and the same
Radial Basis Function (RBF) method to approximate the involved fields and
partial differential operators. First, the results are compared with the data
from the literature in terms of drag coefficient and permeability at different
porosities achieving excellent agreement with the reported results. Next, the
simulations are extended beyond the porosity range reported in the literature
using proposed h-refined CFD solvers. The results are supported by convergence
and timing analyses and discussions on meshless parameters such as stencil size
and refinement settings.
