TY - JOUR
T1 - Numerical study on intrinsic thermoacoustic instability of a laminar premixed flame
AU - Silva, Camilo F.
AU - Emmert, Thomas
AU - Jaensch, Stefan
AU - Polifke, Wolfgang
N1 - Publisher Copyright:
© 2015 The Combustion Institute.
PY - 2015/8/17
Y1 - 2015/8/17
N2 - A study on the velocity sensitivity and intrinsic thermoacoustic stability of a laminar, premixed, Bunsen-type flame is carried out. Direct numerical simulation (DNS) of the flame, placed in an acoustically anechoic environment and subjected to broad-band, low-amplitude acoustic forcing, generates time series of fluctuating heat release rate, velocities and pressure. The time series data is post-processed with system identification to estimate the impulse response and transfer function of the flame. The associated frequency response is validated against experiment with good accuracy. DNS results obtained with acoustic excitation from the inlet or outlet boundary, respectively, confirm that the flame responds predominantly to perturbations of velocity. The stability of eigenmodes related to intrinsic thermoacoustic feedback is investigated with a network model. Both stable and unstable intrinsic thermoacoustic modes are predicted, depending on details of the configuration. The predicted modes are directly observed in direct numerical simulations, with good agreement in frequencies and stability.
AB - A study on the velocity sensitivity and intrinsic thermoacoustic stability of a laminar, premixed, Bunsen-type flame is carried out. Direct numerical simulation (DNS) of the flame, placed in an acoustically anechoic environment and subjected to broad-band, low-amplitude acoustic forcing, generates time series of fluctuating heat release rate, velocities and pressure. The time series data is post-processed with system identification to estimate the impulse response and transfer function of the flame. The associated frequency response is validated against experiment with good accuracy. DNS results obtained with acoustic excitation from the inlet or outlet boundary, respectively, confirm that the flame responds predominantly to perturbations of velocity. The stability of eigenmodes related to intrinsic thermoacoustic feedback is investigated with a network model. Both stable and unstable intrinsic thermoacoustic modes are predicted, depending on details of the configuration. The predicted modes are directly observed in direct numerical simulations, with good agreement in frequencies and stability.
KW - Combustion instability
KW - Finite Impulse Response (FIR)
KW - Flame Transfer Function (FTF)
KW - Intrinsic thermoacoustic feedback
UR - http://www.scopus.com/inward/record.url?scp=84946499877&partnerID=8YFLogxK
U2 - 10.1016/j.combustflame.2015.06.003
DO - 10.1016/j.combustflame.2015.06.003
M3 - Article
AN - SCOPUS:84946499877
SN - 0010-2180
VL - 162
SP - 3370
EP - 3378
JO - Combustion and Flame
JF - Combustion and Flame
IS - 9
ER -