High-speed imaging of fuel/OH distributions in a gas turbine pilot burner at elevated pressure

Different laser visualization techniques were applied to a pilot burner at elevated pressure using relevant liquid fuels. Special care was spent to investigate the performance of the visualization techniques when using Jet-A as fuel compared to when using Bio-Jet as fuel at gas turbine relevant conditions. The burner, a centrally placed generic injector surrounded by a swirling co-flow, was mounted in a high-pressure combustion test rig with optical access from all four sides. Planar laser-induced fluorescence (PLIF) and Mie scattering was used for visualization of the fuel and OH distributions. For fuel PLIF, two different laser excitation wavelengths, 266 nm and 300 nm, were used to investigate the absorption of the laser sheets by different fuels. The Multi:YAG laser cluster, which can produce eight laser pulses in a rapid burst, and a optical parametric oscillator (OPO) was used for high-speed imaging. Furthermore, three-dimensional measurements of fuel PLIF were performed for the Bio-Jet fuel and the OPO laser was used to capture the flame front and burned gas regions using OH PLIF.