Acoustic and flame dynamics analysis of turbulent hydrogen premixed flames at elevated pressures

Abstract

This work examines flame shape, heat release rate (HRR) characteristics and flame acoustics of turbulent premixed hydrogen flames at elevated pressures (1–10 bar), using a novel burner with optical access. Pressure oscillations are measured via two water-cooled transducers mounted in the hot section, while HRR is estimated from OH∗ chemiluminescence captured by a high-speed camera. A wide range of operating conditions is explored, including variations in equivalence ratio, inlet velocity, and pressure. At a fixed flow velocity, increasing pressure shortens the flame and enhances its attachment to the burner rim. Flame speed estimations reveal the critical influence of thermodiffusive instabi..