CFD Study on Hydrogen-Air Premixed Combustion in a Micro Scale Chamber

Abstract

This paper reports a CFD modeling study to investigate the hydrogen-air mixture combustion in a micro scale chamber. Nine species with nineteen reversible reactions were considered in the premixed combustion model. The effect of operational and geometrical conditions including; combustor size, wall conductivity, reactant flow rates and hydrogen feed splitting on combustion stability and outlet gas temperature were investigated. The results show that the wall thermal conductivity has a significant effect on the combustion especially at smaller chamber size with high ratio of chamber surface area to its volume. In addition, the results reveal that high heat loss from chamber wall, small chamber and high input rate may cause flame quenching. Moreover, the modeling results indicate that a stable combustion in a micro combustor can be achieved at an optimum operational condition.

Keywords

• micro combustion
• hydrogen-air
• cfd
• flame temperature
• heat transfer