3D fluid dynamic numerical simulations of different structured open-cell foams are presented: a cubic lattice, the tetrakaidecahedron geometry (Kelvin cell geometry), and the diamond structure. The simulations are done with the open-source software OpenFOAM. Beneath the pressure drops of the different structures, which are compared using dimensionless numbers such as Reynolds number and Euler number, also the development of velocity and its frequency distribution, as an important parameter for chemical reactions, are evaluated. As a main result, the diamond structure provides good conditions with respect to dwell time distributions for the underlying chemical reaction. All the results give a deep knowledge in terms of the underlying principles and optimization approaches. (C) 2014 Elsevier Ltd. All rights reserved.