An experimental study of the pressure and heat release dynamics associated with thermoacoustic instabilities was performed on a 30kW model gas turbine combustor. The combustor consists of an annular swirling air stream with a centrally located Parker Hannifin Research Simplex Atomizer that injects liquid fuel (ethanol) into a dump combustion chamber. An infrared (IR) imaging system has been implemented to visualize the spatial and temporal dynamics of the heat release within the combustor in order to study the effects of active control strategies on suppressing the instabilities. The infrared measurements were acquired in conjunction with heat flux and pressure measurements obtained from high frequency response transducers to investigate the coupling between the heat release and acoustic fields. Time averaged IR emissions show stronger gradients and higher average heat release near the base of the flame with closed-loop control. The results also showed that flow conditions corresponding to higher pressure oscillations in the combustor were characterized by strongly fluctuating compact regions of heat release near the base of the flame.

This content is only available via PDF.
You do not currently have access to this content.