Effect of hydrogen/air ratio on combustion performance of micro combustor

On the basis of the six-wafer combustor used in a micro-gas turbine engine developed by Massachusetts Institute of Technology (MIT), a two-dimensional Computational Fluid Dynamics (CFD) simulation was employed in studying the effect of hydrogen/air ratio on the combustion performance in a micro combustor when the mixture mass flow rate was fixed. The CFD modeling includes the hydrogen/air flow path, combustion chamber as well as the solid walls of the micro-combustor, and the simulation analysis involves in the flow mechanics, heat transfer and the numerous chemical reactions occuring in the micro-combustor. The results show that the flame will be quenched finally in the chamber when the equivalence ratio of fuel/air mixture is 0.4 and the combustion is more stable when the equivalence ratio of fuel/air mixture is 0.5 or 0.6; the flame front will propagate to the upstream of the fuel/air mixture flow, burning in the recirculation jacket when the equivalence ratio is increased to 0.7. It comes to a conclusion that the present numerical simulation is helpful for the design and improvement of the micro-combustor.