Measurement of Particulate Matter and its Oxidation in a Multi-Sector Rich-Quench-Lean Combustor

This paper analyzes 2D soot volume fraction and OH distributions in the fuel-rich primary zone of a three-nozzle rich-burn, quick-quench, lean-burn (RQL) combustor operating with Jet A fuel at elevated pressure. Measurements are made using laser induced incandescence (LII) and OH planar laser induced fluorescence (PLIF) across pressures from 270–480 kPa and global equivalence ratios from 0.1 and 0.2. The instantaneous images indicate that soot and OH occupy different spatial regions of the combustor, with soot from the central flame primarily residing between the central recirculation zone and the OH-containing fuel-lean side of the spray flame between injectors. Statistical analysis demonstrates that — while the total amount of soot in the combustor increases with equivalence ratio at a constant pressure — the percentage of the soot that overlaps with the OH decreases. Similarly, the percentage of soot that overlaps with the OH decreases with increasing pressure at a fixed equivalence ratio. These results articulate the spatial distribution and overall trends of soot production in RQL combustors, as well as the effectiveness of OH in oxidizing soot at these conditions.