TY - JOUR
T1 - Linear instability of a premixed slot flame
T2 - Flame transfer function and resolvent analysis
AU - Wang, Chuhan
AU - Kaiser, Thomas L.
AU - Meindl, Max
AU - Oberleithner, Kilian
AU - Polifke, Wolfgang
AU - Lesshafft, Lutz
N1 - Publisher Copyright:
© 2022 The Combustion Institute
PY - 2022/6/1
Y1 - 2022/6/1
N2 - The response to forcing of a 2D laminar premixed slot flame is investigated by means of linear analysis, based on the compressible flow equations with a two-step reaction scheme for methane combustion. The flame transfer function (FTF) is computed from this linear model, in excellent agreement with reference nonlinear calculations. The input-output gain between externally applied forcing and the global heat release rate response is computed, and peaks in the gain are related to intrinsic thermoacoustic (ITA) modes. The receptivity of the flame to arbitrary flow forcing is characterised by the resulting amplitude of global heat release rate fluctuations. Linear resolvent analysis is used to identify optimal forcing structures and their associated flame response, leading to a discussion of the dominant mechanisms for the amplification of flow perturbations, which trigger flame oscillations. These seem to involve a resonance with ITA instability modes.
AB - The response to forcing of a 2D laminar premixed slot flame is investigated by means of linear analysis, based on the compressible flow equations with a two-step reaction scheme for methane combustion. The flame transfer function (FTF) is computed from this linear model, in excellent agreement with reference nonlinear calculations. The input-output gain between externally applied forcing and the global heat release rate response is computed, and peaks in the gain are related to intrinsic thermoacoustic (ITA) modes. The receptivity of the flame to arbitrary flow forcing is characterised by the resulting amplitude of global heat release rate fluctuations. Linear resolvent analysis is used to identify optimal forcing structures and their associated flame response, leading to a discussion of the dominant mechanisms for the amplification of flow perturbations, which trigger flame oscillations. These seem to involve a resonance with ITA instability modes.
KW - Combustion instability
KW - Flame transfer function
KW - Intrinsic thermoacoustic mode
KW - Linear instability
KW - Premixed laminar flame
KW - Resolvent analysis
U2 - 10.1016/j.combustflame.2022.112016
DO - 10.1016/j.combustflame.2022.112016
M3 - Article
AN - SCOPUS:85126901375
SN - 0010-2180
VL - 240
JO - Combustion and Flame
JF - Combustion and Flame
M1 - 112016
ER -