A numerical investigation on combustion characteristics of H2/air mixture in a micro-combustor with wall cavities

Effect of solid material on the blow-off limit of CH 4 /air flames in a micro combustor with a plate flame holder and preheating channels

“…Wan et al [12] and Fan et al [13] developed a micro bluff-body combustor with excellent flame stabilization performance. Recently, Wan et al [14][15][16] and Yang et al [17] investigated the combustion characteristics of H 2 /air mixtures in micro combustors with cavities, and they confirmed the occurrence of flame tip opening which leads to a decrease in the combustion efficiency. However, for CH 4 /air flames, this phenomenon does not occur and the flame stability was greatly improved [18,19].…”

The impact of channel gap distance on flame splitting limit of H2/air mixture in microchannels with wall cavities

“…They focused on the interactions between homogeneous and heterogeneous combustions. Very recently, we investigated H 2 /air combustion in a microchannel with cavities and confirmed the "flame tip open phenomenon" which occurs under conditions with a Lewis number less than unity [33]. A "flame splitting limit" was defined as the critical inlet velocity at which the fuel conversion ratio drops to 80%.…”

Numerical study of the geometrical parameters on CH4/air premixed combustion in heat recirculation micro-combustor

“…The relatively high average temperature region is found to be blown downwards and distributed among the whole premixed zone when the h is 2°, and the high temperature region becomes longer and thicker by the effect of flow gas, but the temperature value is merely 1350 K. The mixture is accelerated in the converging part of inlet channel when h is 2°, but the area of diverging part of reaction zone is increased suddenly, the mixture begins to decelerate, then the transformation prolongs the residence time and preheating time, both of which promote to releasing a relatively high temperature in the diverging section and quickly spreading to premixed zone. Besides, in the reaction zone, the diverging structure leads to a sharp change in the Reynolds number which is based on feature sizes, particularly near the baffles, the effect of convective heat transfer and conduction are weakened, and the phenomenon improves the average temperature of reaction zone [16,17]. As the area of inlet channel increased, the flow velocity increased slowly and more fresh fuel will be mixed adequately at premixed zone when h is À2°.…”