TY - GEN
T1 - Stability limits and non-linear characteristics of a self-excited combustion instability
AU - Müller, Roel A.J.
AU - Hermann, Jakob
AU - Polifke, Wolfgang
PY - 2012
Y1 - 2012
N2 - Self-excited combustion instabilities of a bluff-body-stabilized premixed flame are investigated. The burner is situated in a duct of rectangular cross-section with closed/open acoustic boundary conditions, representing a quarter-wave acoustic resonator. Fuel gas (methane) is injected through small holes a short distance upstream of the flame, such that it burns in partially premixed mode. Operating points (i.e. thermal power and equivalence ratio) where instability occurs are identified. Variation of amplitude and frequency while operating conditions are changed are discussed for the dominant mode of oscillation, as well as its second and third harmonic. For certain operating points, the harmonics of the first mode seem to couple with higher independent modes. Pressure oscillations during limit cycle operation for one constant operating point are measured along the combustor length. The shape and amplitude of several independent thermo-acoustic modes, as well as the most significant higher harmonics, are reconstructed, identified and interpreted in relation to the combustor geometry. The phase shift between pressure variation at the flame and heat release (Rayleigh index) is discussed for the independent modes, as well as the higher harmonics.
AB - Self-excited combustion instabilities of a bluff-body-stabilized premixed flame are investigated. The burner is situated in a duct of rectangular cross-section with closed/open acoustic boundary conditions, representing a quarter-wave acoustic resonator. Fuel gas (methane) is injected through small holes a short distance upstream of the flame, such that it burns in partially premixed mode. Operating points (i.e. thermal power and equivalence ratio) where instability occurs are identified. Variation of amplitude and frequency while operating conditions are changed are discussed for the dominant mode of oscillation, as well as its second and third harmonic. For certain operating points, the harmonics of the first mode seem to couple with higher independent modes. Pressure oscillations during limit cycle operation for one constant operating point are measured along the combustor length. The shape and amplitude of several independent thermo-acoustic modes, as well as the most significant higher harmonics, are reconstructed, identified and interpreted in relation to the combustor geometry. The phase shift between pressure variation at the flame and heat release (Rayleigh index) is discussed for the independent modes, as well as the higher harmonics.
UR - http://www.scopus.com/inward/record.url?scp=84876254063&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84876254063
SN - 9781622764655
T3 - 19th International Congress on Sound and Vibration 2012, ICSV 2012
SP - 514
EP - 521
BT - 19th International Congress on Sound and Vibration 2012, ICSV 2012
T2 - 19th International Congress on Sound and Vibration 2012, ICSV 2012
Y2 - 8 July 2012 through 12 July 2012
ER -