Investigation of a miniature combustor using porous media surface stabilized flame

In this study, heat recirculation in an annulus around the combustor is utilized together with the flame stabilized on the surface of a porous inert media (PIM) made of silicon-carbide coated carbon foam. The effectiveness of the proposed concept is demonstrated experimentally for methane combustion in chamber volume of 0.364 cm(3) and overall system volume of 1.5 cm(3). Experiments were conducted for reactant flow velocities varying from 0.25 to 1.0 m/s in the equivalence ratio range of 0.50 to 0.80. Measurements include carbon monoxide and nitric oxides concentrations and product gas temperatures at the combustor exit, and temperature profiles on the exterior surface. A computational fluid dynamics (CFD) model incorporating the physics of conjugate heat transfer, radiation heat transfer, flow and heat transfer in the PIM, and heat release by combustion is developed to predict the thermal performance. Results show excellent agreement between measured and computed temperature profiles at different reactant flow rates. The CFD analysis is used to identify important thermal pathways within the system. Finally, a modified design is presented and analyzed computationally. The modified combustion system design achieves a significant reduction in the heat loss as compared to the baseline design tested experimentally.