Propagation of the flame front of methane-air mixture through copper foam within a channel

The dynamics of the flame front in methane-air mixtures within a channel containing copper foam were experimentally studied. The pore density of the copper foam varied from 7 pores per inch (ppi) to 45 ppi. The foam thickness varied from 10 mm to 90 mm. The conditions for flame quenching within the copper foam were measured. The flame front propagation velocities were determined both inside and outside the foam. Two channel configurations were studied: with a constant cross-sectional area and with a sudden expansion. Two methods of ignition were also examined: at the open end of the channel and at the closed end of the channel. It was shown that combustion was quenched when copper foam with a pore density of 45 ppi was utilized. It was shown that the counter-flow of unburned mixture leads to a breakthrough of the flame front when the copper foam of 60 mm or more thickness and with a pore density of 7 ppi was used. Estimates were made that make it possible to evaluate the characteristic time delays of the flame front breakthrough through copper foam. It was shown that the copper foam can be effective when used in tubes of constant cross-section.