Flame stabilization and emission of small Swiss-roll combustors as heaters

Experimental and numerical investigations of flame pattern formations in a radial microchannel

“…However, the increased heat loss due to large surface area-to-volume ratio [3,4] and the wall radical quenching [4] make it difficult to achieve a stable and efficient combustion under reduced scales. Therefore, thermal management, for instance, heat recirculation [5], is frequently adopted in the design of microscale combustors [6][7][8]. In this technique, fresh mixture is preheated by the burned hot gas through solid walls.…”

“…In this technique, fresh mixture is preheated by the burned hot gas through solid walls. The ''Swill roll" combustor is a good example of burners with heat recirculation which has been implemented to stabilize flame in micro-and meso-scales burners [6][7][8]. Many efforts were made to understand fundamentals of micro-to meso-scale combustion with heat recirculation.…”

Regime diagrams and characteristics of flame patterns in radial microchannels with temperature gradients

“…These advantages include energy densities of hydrocarbon fuels that are higher than those of electrochemical batteries (∼20-50 times higher) and abatement of pollutant emission due to lower operating temperatures [15,20]. However, the increased heat loss due to large surface area-volume ratios adversely affects the combustion stability limits in devices and systems employing microscale combustion as well as wall radical destruction does.…”

Experimental study on the unique stability mechanism via miniaturization of jet diffusion flames (microflame) by utilizing preheated air system

“…One thing should be noticed that this observed trend with regard to the stability response against the thermal conductivity seems to contradict to the well-known excess enthalpy combustion concept [e.g. [3][4][5][6][7][8][9][10][11]. There must be at least three reasons to explain; the first is to accumulate heat at the burner tip to increase the temperature to reduce the heat loss from the flame toward the burner, the second is to accumulate heat at the burner tip to enhance the reaction kernel formed at flame leading edge, and the third is to accumulate heat at the burner tip to enhance the potential chemical reaction inside the burner tube (as discussed in Sec.…”

“…Novel combustion devices have been developed to overcome the disadvantage to enlarge the stability limit. One example is a Swiss-roll combustor that consists of two spiral channels with combustion space at the center [3][4][5]. Its fundamental concept is based on excess enthalpy combustion proposed by Weinberg [6] which also have been applied to the porous burner to attain the low-load combustion [7,8]; namely, recirculate the combustion-generated heat toward the unburned premixed gas in pre-burning process.…”