The effect of hydrogen on non-linear flame saturation

Æsøy, Eirik; Indlekofer, Thomas; Bothien, Mirko; Dawson, James R.

doi:10.1115/GT2023-103741

Publication type:	Conference paper
Type of review:	Peer review (publication)
Title:	The effect of hydrogen on non-linear flame saturation
Authors:	Æsøy, Eirik Indlekofer, Thomas Bothien, Mirko Dawson, James R.
et. al:	No
DOI:	10.1115/GT2023-103741
Proceedings:	Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions
Conference details:	ASME Turbo Expo 2023 : Turbomachinery Technical Conference and Exposition, Boston, Massachusetts, USA, 26–30 June 2023
Issue Date:	2023
Publisher / Ed. Institution:	The American Society of Mechanical Engineers
Language:	English
Subjects:	Hydrogen; Flame transfer function; Flame dynamics
Subject (DDC):	620: Engineering
Abstract:	We investigate the effect of increasing levels of hydrogen enrichment on the non-linear saturation of premixed bluff-body stabilised methane/hydrogen flames submitted to acoustic forcing. The thermal power is kept approximately constant to preserve the nozzle velocity whilst increasing the flame speed through hydrogen enrichment. The flame describing function (FDF) is measured for a variety of frequencies and six hydrogen-methane blends ranging from 10% to pure hydrogen by power. We show that when the flame is forced at the same frequency at similar power and bulk velocities, increasing levels of hydrogen enrichment increases the saturation amplitude of the flame. This increase is observed for all cases investigated. To provide insight into the flame dynamics responsible for the change in the saturation amplitude, selected cases were investigated using highspeed imaging in combination with OH-PLIF at different points in the FDF. At lower levels of hydrogen enrichment, the flame is stabilised along the inner shear layer and saturation in the heat release rate occurs at lower forcing amplitudes due to large-scale flame-vortex interactions causing flame annihilation as observed in several previous studies. At high levels of hydrogen enrichment to pure hydrogen, distinctly different flame dynamics are observed. In these cases, the flame accelerates and propagates across to the outer shear layer which acts to suppress large-scale flame annihilation during roll-up of both the inner and outer shear layers. This results in a coherent increase in flame surface area with forcing amplitude significantly increasing the saturation amplitude of the flame. These results show that high levels of hydrogen increases the linear response to acoustic forcing leading to higher saturation amplitudes. This suggests that substituting natural gas with hydrogen in Gas Turbines increases the risk of much higher limit-cycle amplitudes if self-excited instabilities occur.
URI:	https://digitalcollection.zhaw.ch/handle/11475/28971
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Departement:	School of Engineering
Organisational Unit:	Institute of Energy Systems and Fluid Engineering (IEFE)
Appears in collections:	Publikationen School of Engineering

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Æsøy, E., Indlekofer, T., Bothien, M., & Dawson, J. R. (2023). The effect of hydrogen on non-linear flame saturation. Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions. https://doi.org/10.1115/GT2023-103741

Æsøy, E. et al. (2023) ‘The effect of hydrogen on non-linear flame saturation’, in Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions. The American Society of Mechanical Engineers. Available at: https://doi.org/10.1115/GT2023-103741.

E. Æsøy, T. Indlekofer, M. Bothien, and J. R. Dawson, “The effect of hydrogen on non-linear flame saturation,” in Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions, 2023. doi: 10.1115/GT2023-103741.

ÆSØY, Eirik, Thomas INDLEKOFER, Mirko BOTHIEN und James R. DAWSON, 2023. The effect of hydrogen on non-linear flame saturation. In: Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions. Conference paper. The American Society of Mechanical Engineers. 2023

Æsøy, Eirik, Thomas Indlekofer, Mirko Bothien, and James R. Dawson. 2023. “The Effect of Hydrogen on Non-Linear Flame Saturation.” Conference paper. In Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions. The American Society of Mechanical Engineers. https://doi.org/10.1115/GT2023-103741.

Æsøy, Eirik, et al. “The Effect of Hydrogen on Non-Linear Flame Saturation.” Proceedings of the ASME Turbo Expo 2023 : Volume 3B: Combustion, Fuels, and Emissions, The American Society of Mechanical Engineers, 2023, https://doi.org/10.1115/GT2023-103741.