Energy dissipation and permeability in porous media

We investigate flow through porous media by solving the Navier- Stokes equations in 3D porous structures using the lattice Boltzmann method. We analyse the distribution of local specific dissipation of mechanical energy and we use this quantity to investigate the microscopic origin of absolute permeability. The averaging of this quantity on a flow cross-section provides a methodology to locate energy losses and to spot the appropriate scale of the permeability Representative Elementary Volume (REV). The effectiveness of the approach is shown by a numerical study of the flow field in simplified porous media for which experimental results are available.