A numerical study was performed to investigate the chemically reactive flow with liquid spray injection in a staged combustor concept for reducing pollutant emissions. The staged combustor consists of an airblast atomizer, a rich bum section, a converging connecting pipe, a quick mix zone, a diverging connecting pipe, and a lean combustion zone. For computational efficiency, the combustor was split into two subsystems, i.e. the fuel nozzle/rich burn section and the quick quench/lean bum section.
The current study investigates the effect of wall geometry and swirl direction, i.e. co- or counter-rotating swirl, on fuel distribution, temperature distribution, and emissions for the fuel nozzle/rich bum section at a cruise condition. At an equivalence ratio of 1.9, the nozzle-combustor (dome) interface geometry was varied from a flat wall (normal to the combustor wall) to a sloped wall of 45 degrees. It is seen that the sloped wall with co-rotating swirl direction had a substantial effect on combustor performance and reducing pollutant emissions.