Nonlinear dynamics of attenuation behavior in combustion oscillations in a swirl-stabilized combustor

Abstract

We experimentally examine the attenuation behavior in combustion oscillations from the perspective of symbolic dynamics, dynamical systems theory, complex networks, and machine learning. The periodicity of combustion oscillations gradually decreases with increasing amount of air steadily injected into flame base, maintaining a nearly in-phase synchronized state between pressure and OH* chemiluminescence emission intensity fluctuations. Both the dynamic behaviors of pressure and OH* chemiluminescence emission intensity fluctuations in the attenuation regime close to well-suppressed combustion oscillations exhibit pseudo-periodic oscillations with deterministically nonperiodic intercycle dynamics. They lead to noisy chaotic oscillations and exhibit a desynchronized state during well-suppressed combustion oscillations.