Investigation of performances of innovative aeronautic injection systems using advanced laser diagnostics

Office National d'Etudes et de Recherches Aérospatiales Chemin de la Hunière, Palaiseau 91761, France

Abstract

Simultaneous measurements of Planar Laser-Induced Fluorescence (PLIF) kerosene and PLIF-OH have been successfully performed in a multipoint injection system for various overall equivalence ratios, air inlet temperatures between 480 and 730 K, and pressures up to 2.2 MPa. Single-shot two-dimensional (2D) maps of the spatial distribution of kerosene vapor and OH radical in the combustor have been recorded with good signal-to-noise ratio. Results show that depending on the split between the pilot and the main injectors, the flame front exhibits either a single or a double structure. Good spatial correlation between the repartition of kerosene vapor and the position of the flame front was observed; in particular, no “dark zone” is observed between the fuel and the flame front. As temperature and pressure increase, fuel evaporation improves and the spatial distribution of OH radical becomes more homogeneous in the combustor, suggesting a partially-distributed combustion.