Abstract
Combustion at small-scales is challenging because of the high heat loss and short flow residence time. This study features a combustor with porous inert media surrounded by an annulus. Reactants enter the annulus and are preheated by combustion heat that would otherwise be lost to the surroundings. Detailed computational fluid dynamics analysis is performed to identify design features with minimum heat loss. Analysis revealed coupled heat transfer pathways, i.e., reducing heat loss by axial conduction increases it by radiation and vice versa. Results show that the development of efficient small-scale combustion systems requires an accurate analysis of the coupled thermal pathways.