Time-resolved temperature profile measurements in the exhaust of a single sector gas turbine combustor at realistic operating conditions

Records of the time-varying temperature profile at flight relevant operating conditions are acquired at the exit of a combustion chamber fitted with a staged, lean-burn fuel injector using high-speed laser induced fluorescence (LIF) at a sample rate of 10 kHz. Temperatures are estimated from the concentration dependent fluorescence of the hydroxyl (OH) radical under the assumption of local equilibrium. Beyond the time-series analysis, the acquired data is correlated with simultaneously acquired OH chemiluminescence sampled in the primary zone near the fuel injector. These analyses reveal a strong influence from the precessing vortex core, originating in the primary zone, on oscillations in the temperature profiles measured at the exit of the combustor.