Mutual synchronization and quenching in two coupled thermoacoustic oscillators

We experimentally investigate mutual synchronization and quenching in two thermoacoustic oscillators interacting via dissipative and time-delayed coupling. Acoustic pressure measurements yield phase differences and amplitude-suppression ratios, enabling a thorough characterization of the coupled oscillator dynamics. A systematic parametric study across a wide range of coupling strengths and time delays reveals a complex dynamical landscape comprising in-phase/anti-phase synchronization, desynchronization, and amplitude death. At a fixed time delay, increasing the dissipative coupling strength induces three distinct bifurcation pathways: a transition from desynchronization to in-phase synchronization via gradual oscillation suppression, a direct transition to amplitude death, and a progressive phase-locking process. These findings provide useful insights into the fundamental dynamical transitions in coupled oscillator systems, informing passive control strategies for mitigating thermoacoustic instabilities in combustion devices.