Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration

Gopalakrishnan, Harish S.; Heggset, Tarjei; Gruber, Andrea; Bothien, Mirko R.; Moeck, Jonas

doi:10.21256/zhaw-29566

Please use this identifier to cite or link to this item: https://doi.org/10.21256/zhaw-29566

Publication type:	Conference paper
Type of review:	Peer review (publication)
Title:	Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration
Authors:	Gopalakrishnan, Harish S. Heggset, Tarjei Gruber, Andrea Bothien, Mirko R. Moeck, Jonas
et. al:	No
DOI:	10.21256/zhaw-29566
Conference details:	Symposium on Thermoacoustics in Combustion: Industry meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023
Issue Date:	Sep-2023
Publisher / Ed. Institution:	ZHAW Zürcher Hochschule für Angewandte Wissenschaften
Language:	English
Subjects:	Combustion instability; Autoignition-stabilized flame; Reheat combustor; Flame response; Thermoacoustics
Subject (DDC):	530: Physics 620: Engineering
Abstract:	Hydrogen combustion in a sequential combustor with a propagation-stabilized flame in the first stage and an autoignition-stabilized flame in the second reheat stage offers fuel flexible and efficient power generation with minimal greenhouse gas emissions. However, unsteady thermoacoustic phenomena driven by the interactions between the flame dynamics and the combustor acoustics can result in large amplitude heat release rate and pressure oscillations, which can cause hardware damage and performance losses. A key component required to understand and predict thermoacoustic oscillations in reheat combustors is the knowledge of the response of the autoignition-stabilized flame to unsteady acoustic and convective disturbances. In this paper, we extend a simplified particle based framework, originally proposed for computing the flame response in a simple one-dimensional reheat combustor configuration (Gopalakrishnan et al. 2021), to a two-dimensional backward-facing step geometry. The present particle based framework treats the flow as a collection of independent Lagrangian fluid elements which evolve in time. The temperature evolution of each fluid particle is computed by integrating the momentum, energy and species mass balance equations for that particle in time. The unsteady heat release rate and instantaneous flame position are then computed by stitching together the particle evolution data. The predictions of the flame response framework are thereafter compared with fully compressible Large eddy simulations (LES) of a reheat flame forced by acoustic and entropy disturbances. The flame response predictions obtained from the present approach match well with the LES data, suggesting that the present particle based framework can be used to compute flame transfer functions of reheat flames and consequently give insight into the thermoacoustic stability characteristics of reheat combustors.
URI:	https://digitalcollection.zhaw.ch/handle/11475/29566
Fulltext version:	Accepted 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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Gopalakrishnan, H. S., Heggset, T., Gruber, A., Bothien, M. R., & Moeck, J. (2023, September). Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration. Symposium on Thermoacoustics in Combustion: Industry Meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023. https://doi.org/10.21256/zhaw-29566

Gopalakrishnan, H.S. et al. (2023) ‘Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration’, in Symposium on Thermoacoustics in Combustion: Industry meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023. ZHAW Zürcher Hochschule für Angewandte Wissenschaften. Available at: https://doi.org/10.21256/zhaw-29566.

H. S. Gopalakrishnan, T. Heggset, A. Gruber, M. R. Bothien, and J. Moeck, “Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration,” in Symposium on Thermoacoustics in Combustion: Industry meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023, Sep. 2023. doi: 10.21256/zhaw-29566.

GOPALAKRISHNAN, Harish S., Tarjei HEGGSET, Andrea GRUBER, Mirko R. BOTHIEN und Jonas MOECK, 2023. Prediction of autoignition-stabilized flame dynamics in a backward-facing step reheat combustor configuration. In: Symposium on Thermoacoustics in Combustion: Industry meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023. Conference paper. ZHAW Zürcher Hochschule für Angewandte Wissenschaften. September 2023

Gopalakrishnan, Harish S., Tarjei Heggset, Andrea Gruber, Mirko R. Bothien, and Jonas Moeck. 2023. “Prediction of Autoignition-Stabilized Flame Dynamics in a Backward-Facing Step Reheat Combustor Configuration.” Conference paper. In Symposium on Thermoacoustics in Combustion: Industry Meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023. ZHAW Zürcher Hochschule für Angewandte Wissenschaften. https://doi.org/10.21256/zhaw-29566.

Gopalakrishnan, Harish S., et al. “Prediction of Autoignition-Stabilized Flame Dynamics in a Backward-Facing Step Reheat Combustor Configuration.” Symposium on Thermoacoustics in Combustion: Industry Meets Academia (SoTiC), Zurich, Switzerland, 11-14 September 2023, ZHAW Zürcher Hochschule für Angewandte Wissenschaften, 2023, https://doi.org/10.21256/zhaw-29566.