Numerical analysis on combustion flow characteristics of jet-stabilized combustor with different geometry

In this study, three novel jet-stabilized combustor geometries with cavity, vertical ring and vertical pipe are respectively proposed, the combustion and emission characteristics are numerically investigated and compared with the original geometry. The realizable k - epsilon model and presumed probability density functions (PDF) model are used for turbulent combustion, and the nitrogen oxide (NOx) formation model is used for nitric oxide (NO) emission. The results show that two vortex pairs formed in primary zone under four cases, but for the combustor with vertical ring, a vortex pair also appears downstream of air jet holes. For the combustor with vertical pipe geometry, the right-side vortex pair is the biggest, meanwhile the extrusion effect on the left vortexes is obvious. The high-temperature zone is mainly located in the primary zone and downstream of air jet holes for all cases, while the combustor with vertical ring have the smallest high temperature region, and it with a uniform temperature distribution. The outlet temperature distribution factor is lower than 0.036 for all combustors. Compared with the original combustor, the NO emission of combustors with cavity and vertical ring decrease respectively by 31% and 52%, while the NO emission of combustor with vertical pipe increases by 32%.

Automated summary

This study proposes three novel geometries for jet-stabilized combustors and compares their combustion and emission characteristics with the original geometry. The results show different vortex formations in the combustors, with the one featuring a vertical ring having the smallest high-temperature region and a uniform temperature distribution. Compared to the original combustor, the NO emission decreases by 31% and 52% for the combustors with cavity and vertical ring, while it increases by 32% for the combustor with vertical pipe.