Abstract: In order to improve the combustion performance of methane in a micro planar combustor, 2D numerical simulation on premixed combustion process of methane with hydrogen addition is conducted, and the combustion characteristics of mixed fuel under different mixing ratio and channel height are studied. The results show that the addition of hydrogen can stabilize the flame and enhance the burning velocity when equivalent ratio is 0.8. When the addition ratio is in the range of 5% to 25%, the flame front gradually moves forward with the increase of the hydrogen mass fraction. The highest temperature of flame can get an average growth of 101 K as the addition ratio is increased by 5%. Along with the increase of the hydrogen mass fraction, the mole fraction of OH raises gradually while the amount of CO2 decreases apparently, and the generation rate of CO2 presents a tendency of rising slowly before it falling sharply. In addition, the addition of hydrogen can solve the question that the methane is difficult to combust inside a channel with the height less than 2.5 mm. When the channel height decreases from 3 mm to 1 mm, the corresponding generation rate of CO2 reduces gradually. The flame center reached the maximum temperature of 2 260 K when the channel height is 4 mm, and the CO2 mole fraction at the exit is lower than that of other three cases.

Key words: channel height, CO2 generation rate, flame stabilization, hydrogen-enriched methane, micro-combustor, OH mole fraction