Concurrent measurement of combustion oscillation and temperature of multiple flames in a simulated gas turbine

A vision-based instrumentation system for the measurement of oscillation frequency and temperature distribution of multiple flames in a gas turbine combustor is developed and tested. The system, utilising imaging, spectral analysis and two-colour pyrometry techniques, is capable of monitoring the oscillation frequency and temperature distribution of up to eight flames concurrently and simultaneously. The relative error of the system for frequency measurement is less than 1% (0-100 Hz) whilst for temperature measurement it is no greater than 2% (1000°C-1500°C). Experimental results obtained on a simulated gas turbine have demonstrated that the fundamental frequency of the flame measured by the system responds in predictable ways to the excitation frequency of fuel flow. Further development is underway to apply the technique to a practical gas turbine combustor.