Experimental Implementation of Retrospective Cost Adaptive Control for Suppressing Thermoacoustic Oscillations in a Rijke Tube

Thermoacoustic systems are self-oscillating due to the fact that a constant input (e.g., fuel rate in gas-turbine combustors) yields an asymptotically oscillatory response. This behavior arises from the interaction between combustion and acoustics, resulting in thermoacoustic oscillations. Under varying operating conditions, the dynamics of thermoacoustic systems may change dramatically, which may require that active suppression controllers can be tuned for specific working conditions. This work provides an experimental investigation of retrospective cost adaptive control for suppressing thermoacoustic oscillations under sampled-data control and varying system operating conditions. This approach is first applied to a Rijke-tube emulation model for hyperparameter selection and subsequently to an experimental Rijke-tube setup. Physical experiments are conducted to investigate the performance and robustness of the adaptive controller under varying operating conditions.