An extensive study on morphological parameters of ceramic sponge structures of different material, porosity, and pores per linear inch (ppi) number was performed. Volume image analyses of magnetic resonance imaging (MRI) and X-ray tomography (CT) measurements were carried out to determine experimentally the geometric specific surface area of the structures. Furthermore, face and strut diameters, porosities, and densities were assessed through conventional methods including optical microscopy, mercury porosimetry, and helium pycnometry. The resulting data were used to evaluate morphological models representing the irregular strut network by packings of regular polyhedra. On the basis of an adapted Weaire-Phelan model, a novel correlation was developed that enables the calculation of the specific surface area of sponges with high accuracy. The input parameters for this correlation are easily accessible by standard microscopy and porosimetry measurements.

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A quasi-DNS of the partially premixed turbulent Sydney flame in configuration FJ200-5GP-Lr75-57 has been conducted using detailed molecular diffusion for multi-component mixtures and complex reaction mechanisms. In order to study flame dynamics like regime transition in this flame for the development of new combustion models and to directly compare the quasi-DNS to different LES models, the simulation results are compiled into a data base. Because the simulation was performed with OpenFOAM, we demonstrate the quasi-DNS capabilities of OpenFOAM by performing canonical test cases. They attest that OpenFOAM’s cubic discretization has lower numerical diffusion compared to classical central difference schemes and can reach higher than second order convergence rate in some cases. The quasi-DNS of the Sydney flame is conducted with a self-developed reacting flow solver which is able to accurately compute molecular diffusion coefficients from kinetic gas theory and employs a fast implementation for detailed reaction mechanisms. The computational mesh is shown to be able to resolve the flow as well as the flame front sufficiently for the quasi-DNS. Comparisons with experimental data also show that the simulation can quantitatively reproduce measured time-mean and time-RMS statistics.

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