Behavior of Transient Hydrogen Enriched Jet-In-Crossflow

Hydrogen-enriched natural gas leads to a reduced carbon-based emission but has a increased risk to flashback into the injector. It is critical to identify a mechanisms in which flashback can be identified in order to enable broader and more intensive research into flashback characterization and mitigation. This study investigates the use of a high-bandwidth PCB piezoelectric pressure transducer combined with Fast Fourier Transform (FFT) spectral analysis to identify combustion-acoustic signatures associated with flashback in a high-pressure axially staged hydrogen jet-in-crossflow (JICF) facility. Pressure data was collected upstream of the axial injector for both lifted-flame and flashback-prone operating conditions, and the resulting frequency-domain spectra were examined across key transient regions of the experiment. flashback events produced distinct high-frequency spectral peaks at approximately 2310 Hz and 2875 Hz, frequencies absent during normal lifted-flame operation and suggest potential applications in flashback detection learning models.