Numerical Simulation of Air Inlet Conditions Influence on the Establishment of MILD Combustion in Stagnation Point Reverse Flow Combustor

摘要

This paper presents a numerical study of the nonpremixed stagnation point reverse flow (SPRF) combustor, especially focusing on the influence of air inlet conditions. Modified eddy dissipation concept (EDC) with a reduced mechanism was used to calculate the characteristic of MILD combustion. The results show that the modified EDC with DRM19 mechanism is suitable for the present simulations. Seven additional runs are conducted to find out that it is not necessary to include the influence of low oxygen despite its conduciveness to the establishment of MILD combustion in SPRF combustor. In addition, for the same mass rate of air inlet, it is difficult to reach MILD combustion mode by changing the velocity of the air inlet. The influence of air inlet momentum is also investigated by keeping the air inlet velocity constant and increasing the mass. Although the degree of recirculation (R_(eg)) is small, it can still achieve MILD combustion mode. Compared with the influence of air inlet velocity, it could be concluded that, rather than R_(eg), the recirculation flow rate is the most important factor.