Single-Surface Flame Quenching Distance Dependence on Wall Temperature, Quenching Geometry, and Turbulence

The effect of wall temperature on single-surface flame quenching distance was characterized for atmospheric, premixed methane-air flames. The study includes a comparison of the wall temperature dependent, single-surface flame quenching distance for laminar and turbulent flames. The laminar flame-Wall interaction was studied for flames that were configured at angles near 0° and 45° relative to a temperature-controlled surface. For each flame quenching configuration, the flame quenching distance was chosen as the location from the surface for which a constant value of C₂ concentration occurred; spatially resolved measurements of C₂ concentration were obtained with the technique of laser-induced fluorescence. The results indicated that the single-surface flame quenching distance, for each flame configuration, decreased with increasing wall temperature. For the laminar flames, Ramanbased gas temperature measurements indicated that the near-wall temperature gradient was reduced when the wall temperature was increased. The wall heat flux was estimated from the measured near-wall temperature profile and gas thermal conductivity. These results indicated that the wall heat flux decreased for the laminar sidewall flame and increased for the laminar stagnation flame for increasing wall temperature from 250 °C to 600 °C.