Direct pore level simulation of premixed gas combustion in porous inert media using detailed chemical kinetics

Combustion inside of an inert ceramic matrix offers the possibility to gain high flame stability at ultra-lean conditions combined with relatively high thermal loads and low emission of pollutants. The solid matrix contributes to this behavior due to its high thermal conductivity and also high thermal inertia. Both properties lead to good stabilization and homogenization of the reaction zone. As the experimental access, optical as well as with probes, is inherently limited due to the solid structure, numerical examination of the reacting flow field is done via 3D direct solution of the momentum, energy and species balance equations without further modeling assumption for the solution of the flow field (direct pore level simulation, DPLS). The Kee reaction mechanism including 17 species and 58 reactions is integrated in the solver for the calculation of the species conversion. The results of the 3D DPLS are compared with experimental data of a cylindrical, axial-flow porous burner and show good agreement with respect to temperature and macroscopic flame thickness. The DPLS results showed that the flame structure is substantially affected by the topology of the PIM at the pore level.