TY - GEN
T1 - Flame-flow interactions and flow reversal
AU - Bansal, Gaurav
AU - Im, Hong G.
AU - Bechtold, John K.
N1 - Funding Information:
GB and HGI were in part supported by the University Consortium on Low Temperature Combustion for High-Efficiency, Ultra-Low Emission Engines directed by the University of Michigan and funded by the Department of Energy. JKB was supported by the National Science Foundation Grant DMS-0807340.
PY - 2010
Y1 - 2010
N2 - The interaction of a premixed methane/air flame with flow unsteadiness is studied computationally using a stagnation-point flow configuration. The problem is of fundamental interest and also relevant for turbulent combustion in the laminar flamelet regime. In the present study, of particular interest is the flame residing in a weakly strained flow field such that the flame is stabilized away from the viscous boundary layer adjacent to the stagnation plane and is free to move in response to flow perturbations. An unsteady sinusoidal strain rate field is imposed on the flame, and an extensive parametric study is conducted by varying the frequency and amplitude of strain rate fluctuation. It is found that for high frequencies and large amplitudes, flow direction reverses upstream of the flame, thereby establishing a new stagnation plane in the preheat zone ahead of the flame. This observation indicates that the flame strongly effects the upstream flow field and could also possibly explain the reported occurence of flow reversal in experimental studies of turbulent jet flames. Lewis number effects on flame-flow interaction and flow reversal is studied by investigating highly lean (Le < 1) and rich (Le > 1) hydrogen/air flames. Comparisons of the results are made with an earlier theoretical study of flame-flow interactions incorporating a hydrodynamic model
AB - The interaction of a premixed methane/air flame with flow unsteadiness is studied computationally using a stagnation-point flow configuration. The problem is of fundamental interest and also relevant for turbulent combustion in the laminar flamelet regime. In the present study, of particular interest is the flame residing in a weakly strained flow field such that the flame is stabilized away from the viscous boundary layer adjacent to the stagnation plane and is free to move in response to flow perturbations. An unsteady sinusoidal strain rate field is imposed on the flame, and an extensive parametric study is conducted by varying the frequency and amplitude of strain rate fluctuation. It is found that for high frequencies and large amplitudes, flow direction reverses upstream of the flame, thereby establishing a new stagnation plane in the preheat zone ahead of the flame. This observation indicates that the flame strongly effects the upstream flow field and could also possibly explain the reported occurence of flow reversal in experimental studies of turbulent jet flames. Lewis number effects on flame-flow interaction and flow reversal is studied by investigating highly lean (Le < 1) and rich (Le > 1) hydrogen/air flames. Comparisons of the results are made with an earlier theoretical study of flame-flow interactions incorporating a hydrodynamic model
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M3 - Conference contribution
AN - SCOPUS:78649843934
SN - 9781600867392
T3 - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
BT - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
T2 - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
Y2 - 4 January 2010 through 7 January 2010
ER -