Effects of flame behaviors on combustion noise from lean-premixed hydrogen low-swirl flames

Takeshi Shoji, Yuki Iwasaki, Kato Kodai, Seiji Yoshida, Shigeru Tachibana, Takeshi Yokomori

Research output: Contribution to journalArticlepeer-review

Abstract

This experimental study explored the influence of global/local flame behaviors on direct combustion noise produced by a lean-premixed gaseous H2 ∕air low-swirl turbulent jet flame, with a focus on the mechanism resulting in characteristic peaks in combustion noise spectra. Ten kilohertz OH chemiluminescence and OH planar laser-induced fluorescence (OH-PLIF) imaging were used to study the spatiotemporal evolution of heat release and flame structure fluctuations, respectively, whereas 2-D particle image velocimetry (2-D PIV) measurements at 4 Hz were applied to study the mean-based relation between the velocity/vorticity fields and flame structures. Pressure and global heat release fluctuation measurements carried out alongside these optical diagnostics revealed pronounced double peaks in both combustion noise and global heat release fluctuation spectra at global equivalence ratios of ϕ ≥ 0.45. Spectral proper orthogonal decomposition of the OH chemiluminescence and OH-PLIF images revealed that the first peak in the noise spectra to be caused by flame oscillations over nearly the entire flame region, whereas the secondary peak was attributed to periodically generated vortical flame structures near the downstream side of the flame boundary. The 2-D PIV results suggest that vortical flame structures are likely generated by the interaction between the flame and the inner/outer shear layers.

Original languageEnglish
Pages (from-to)4505-4521
Number of pages17
JournalAIAA journal
Volume58
Issue number10
DOIs
Publication statusPublished - 2020

ASJC Scopus subject areas

  • Aerospace Engineering

Fingerprint

Dive into the research topics of 'Effects of flame behaviors on combustion noise from lean-premixed hydrogen low-swirl flames'. Together they form a unique fingerprint.

Cite this