Laser-induced phosphorescence applied in the flame wall impinging process

This study investigated premixed flame propagation and the wall temperature change during flame impingement in a constant-volume bomb. The experiments compared stoichiometric methane-air and lean (equivalence ratio of 0.5) hydrogen-air mixtures, which were prepared to have similar laminar burning velocities. Flame propagation was visualized using the shadowgraph technique, while wall temperature distributions were measured using laser-induced phosphorescence (LIP) with YAG:Dy. Despite the similar laminar burning velocities, the results revealed that hydrogen flames propagated faster and reached the wall in less time than methane flames. Another finding was that the rate of wall temperature rise after flame impingement is greater for hydrogen flames than for methane flames. This is because, despite the lower adiabatic flame temperature, the temperature boundary layer is thinner and the heat flux is greater.