Dynamical Characterization of Thermoacoustic Oscillations in a Hydrogen-Enriched Partially Premixed Swirl-Stabilized Methane/Air Combustor

Abstract In this study, we systematically analyze the effects of hydrogen enrichment in well-known PRECCINSTA burner, a partially premixed swirl-stabilized methane/air combustor. Keeping equivalence ratio and thermal power constant, vary percentage fuel. Successive increments fuel fraction increase adiabatic flame temperature also shift dominant frequencies acoustic pressure fluctuations to higher values. Under enrichment, observe emergence periodicity combustor resulting from interaction between modes. As result these modes, exhibits variety dynamical states, including period-1 limit cycle oscillations (LCO), period-2 LCO, chaotic oscillations, intermittency. The flow behavior is found be significantly different for each state. Analyzing coupled heat release rate during states thermoacoustic instability, report occurrence 2:1 frequency-locking where two cycles lock with one rate. During notice 1:1 frequency-locking, both repeat their every cycle.