Experimental Investigation of a High Power Density Ceramic Mesoscale Combustor

A mesoscale heat recirculating combustor design which incorporates a combustion chamber at the center and double spiral-shaped channels in the form of Swiss-roll for inlet and exhaust have been used to experimentally examine the detailed characteristics of small scale combustion. The widths of the combustion chamber and the channels were smaller than the minimum quenching distance of the flame at a normal state. At these small scales thermal management is very significant. The design incorporates a low thermal conductivity material for the combustor design. The study was performed using premixed mixture of propane and air in a combustion chamber designed to induce sufficient flow recirculation. Flames could be stabilized successfully over a wide range of equivalence ratios and Reynolds numbers. Blow-off was not observed for the set of experimental conditions investigated. Propane–air flame could be sustained in a volume as small as 32mm 3 . Flame could be sustained at average velocities as high as 11m/s which is about 25 times higher than the laminar flame speed. The power density of the combustion chamber of this combustor was as high as 5.6GW/m3. Thermal images of the combustor walls under steady state conditions were obtained using an infrared camera. These images showed that the combustor was capable of sustaining high thermal gradients between the central chamber and the outer walls.