Pressure and velocity profiles obtained numerically in a sandpack. The sandpack 1.2 mm × 1.2 mm × 2.16 mm three-dimensional images have been obtained using microtomography. The flow simulation is carried out with OpenFOAM. The velocity vectors and magnitude illustrate the tortuous and non-uniform distribution of the flow pathways in the pore-space. The velocity vectors are colored with the pressure field. The profiles are normalized by the maximum and minimum values and range between 0 (blue) and 1 (red).