Experimental and numerical study of methane-oxygen combustion in a microtube

Two mixture ratios of gaseous oxygen and methane were combusted in the micro-tube to study the micro-combustor characteristics. The wall temperatures of the micro-combustor were measured at various positions. A 3-D numerical simulation of the micro-tube combustion was also developed taking into account the combustion, flow and heat transfer in the micro-tube. The tests and numerical results showed that the small inner diameter of the micro-tube required a long tube to achieve complete combustion. The heat transfer between the micro-tube and the environment was very large, accounting for about 40% of the total combustion heat, the radiation heat loss was the largest, accounting for 70% of the total heat losses. Therefore, low emissivity materials are necessary to reduce the radiation heat loss from the micro-combustor wall.