On the relationship between H2 addition, local extinction and hydrodynamic instability in non-premixed bluff-body stabilized flames
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Published version
Author(s)
Rajamanickam, Kuppuraj
Cessou, Armelle
Lecordier, Bertrand
Rajamanickam, Kuppuraj
Type
Conference Paper
Abstract
We examined the effect of hydrogen (H2) enrichment on methane (CH4) in a canonical non-premixed bluff-body stabilized burner operating under typical central jet-dominated flame mode. In the chosen mode of operation, globally, the flow field and flame feature three important successive spatial regions: the recirculation zone, neck zone and jet-like flame zone. In such configuration, the flame is exposed to a higher stretch rate in the neck zone and eventually undergoes local extinction. Such local extinction and subsequent re-ignition of broken flame branches have strong implications over the hydrodynamic instability of the coaxial annular air shear layer. It is well known that H2 addition increases the flame extinction strain rate and thus alters the local extinction phenomenon. To understand this phenomenon, we performed experiments at 10%, 20 %, 30%, and 50 % hydrogen proportion in the H2-CH4 blend. High repetition rate (5 KHz) PIV and OH PLIF measurements are performed simultaneously to perceive the quantitative insights. The results obtained from POD and 1D wavelet transform indicated the suppression of vortex shedding at the annular air shear layer for H2 addition greater than 20 %, and thus quantified the beneficial effect of H2 addition in turbulent flame stabilization.
Date Issued
2022-07-11
Date Acceptance
2022-03-01
Citation
Proceedings of the20th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics, 2022
Journal / Book Title
Proceedings of the20th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics
Copyright Statement
© 2022 The Author(s).
Source
20th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics,
Publication Status
Published
Start Date
2022-07-11
Finish Date
2022-07-14
Coverage Spatial
Lisbon, Portugal