Linear stability and resolvent analyses of a bluff-body stabilized flame with conjugate heat transfer

Fuente: arXiv
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Main Authors: Chen, Lu, Chan, Wai Lee, Lv, Yu
Format: Preprint
Published: 2024
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author Chen, Lu
Chan, Wai Lee
Lv, Yu
author_facet Chen, Lu
Chan, Wai Lee
Lv, Yu
contents Conjugate heat transfer is a challenging fluid-structure coupling problem that can significantly influence flame stabilization and thermoacoustic instabilities. To properly capture combustion phenomena that involve conjugate heat transfer, careful modeling of chemical reactions in the fluid domain and heat transfer in the solid body is necessary and remains an active research topic. To this end, we derived a strongly-coupled method with a monolithic weak formulation to investigate the conjugate heat transfer between an anchored flame and a thermal conductive cylinder by means of linear stability analysis and resolvent analysis. We conduct parameter continuation with the Damkohler number to construct a bifurcation diagram and identify multiple baseflow states, including blow-off, anchored flame, and flashback. Linear stability analysis reveals the presence of a single unstable, non-oscillatory eigenmode for the base states on the anchored flame branch. This eigenmode plays a pivotal role in driving the bifurcation. Subsequently, resolvent analysis is performed to examine the amplification behavior of the fluid-solid coupled system under external forcing, showing that heat fluctuations are maximized when heat transfer between the fluid and solid is minimized.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13539
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Linear stability and resolvent analyses of a bluff-body stabilized flame with conjugate heat transfer
Chen, Lu
Chan, Wai Lee
Lv, Yu
Fluid Dynamics
Conjugate heat transfer is a challenging fluid-structure coupling problem that can significantly influence flame stabilization and thermoacoustic instabilities. To properly capture combustion phenomena that involve conjugate heat transfer, careful modeling of chemical reactions in the fluid domain and heat transfer in the solid body is necessary and remains an active research topic. To this end, we derived a strongly-coupled method with a monolithic weak formulation to investigate the conjugate heat transfer between an anchored flame and a thermal conductive cylinder by means of linear stability analysis and resolvent analysis. We conduct parameter continuation with the Damkohler number to construct a bifurcation diagram and identify multiple baseflow states, including blow-off, anchored flame, and flashback. Linear stability analysis reveals the presence of a single unstable, non-oscillatory eigenmode for the base states on the anchored flame branch. This eigenmode plays a pivotal role in driving the bifurcation. Subsequently, resolvent analysis is performed to examine the amplification behavior of the fluid-solid coupled system under external forcing, showing that heat fluctuations are maximized when heat transfer between the fluid and solid is minimized.
title Linear stability and resolvent analyses of a bluff-body stabilized flame with conjugate heat transfer
topic Fluid Dynamics
url https://arxiv.org/abs/2412.13539