Experimental and Numerical Study on the Laminar Premixed Flame Stabilized Inside a Honeycomb Ceramic

Abstract

A laminar premixed flame stabilized inside a honeycomb ceramic was experimentally as well as theoretically investigated here. In previous theoretical studies a stable flame has been predicted in the downstream region of the combustor, but it has never been observed in experiments. In this study, a stable downstream flame could be obtained for the lower burning velocity through circumferential heating by a blue flame positioned outside the periphery of the specially devised combustor. The existence of the stable downstream flame was confirmed by a direct photography of soot line, and temperature measurements. In this case the measured flame temperature was found to be lower than the adiabatic flame temperature due to its lower heat release

The one-dimensional flame analysis was also carried out by taking account of the side heating resulting from the blue flame. The downstream as well as upstream solution corresponding to upper and lower solutions could be obtained. Once the net heat recirculation condition was satisfied for a given flow condition, the numerical procedure was stopped and the solution was thought to be obtained. That is how both upstream and downstream flames could be found for a given mass flow rate. However, in order for the downstream flame to be stabilized, more heat needed to be recirculated towards upstream.

Key words:

• Laminar
• premixed flame
• porous medium
• radiation
• heat recirculation