Patterns of hydrogen flame propagation and acceleration in the channels with copper foam

Abstract

We detailed the experimental situation concerning the influence of porous copper on the flame propagation in the channel in hydrogen-air. The experiments were carried out at atmospheric pressure in lean mixtures undiluted by inert gases at a molar excess of hydrogen of 0.3–0.6. The propagation of the flame front was studied using high-speed schlieren visualization and a high-speed infrared visualization at the same time. The patterns of flame velocity dynamics when passing through copper foam were determined. Two fundamental methods of flame initiation were used: at the open end of the open channel and at the closed end of the semi-open channel. It was shown that at the initial stage of the flame propagation through the copper foam with a large pore size the flame accelerates. It was shown that the foam contributes more to the relative flame acceleration when initiated at the open end. The conditions for flame quenching and passing through the copper foam were determined depending on the mixture composition, the length of the foam (from 10 mm to 90 mm) and the pore density (from 7 to 45 pores per inch).