TY - JOUR
T1 - On colliding spherical flames
T2 - Morphology, corner dynamics, and flame-generated vorticity
AU - Yang, Sheng
AU - Zhu, Delin
AU - Law, Chung K.
N1 - Funding Information:
This work was supported in part by the NASA Microgravity Combustion program. We thank Professor Swetaprovo Chaudhuri for his advice with the computation.
Publisher Copyright:
© 2015 The Combustion Institute.
PY - 2016/5/1
Y1 - 2016/5/1
N2 - The collision of two identical spherical flames was studied for its relevance in flame interactions in various practical situations including those within turbulent flames. Experimentally, premixtures of fuel (H2, C3H8) and oxidizer were ignited by two synchronized sparks in a closed chamber under atmospheric pressure, with the subsequent flame-front evolution tracked by a Schlieren system with high-speed camera, as well as computationally simulated. Results show that development of the morphology of flame collision can be distinguished in three stages: independent propagation, strong interaction with flattened interfaces, and corner dynamics after merging of the interfaces. It is further demonstrated that propagation of the flame corner is controlled by the interacting mechanisms of preferential diffusion and kinematic restoration, that vorticity of considerable strength is generated downstream of the corner flame segment, and that the kinetic energy of the flame-generated vorticity is substantial as compared to those of the Kolmogorov eddies such that it could have strong influence on the turbulence energy spectrum and flame burning rate.
AB - The collision of two identical spherical flames was studied for its relevance in flame interactions in various practical situations including those within turbulent flames. Experimentally, premixtures of fuel (H2, C3H8) and oxidizer were ignited by two synchronized sparks in a closed chamber under atmospheric pressure, with the subsequent flame-front evolution tracked by a Schlieren system with high-speed camera, as well as computationally simulated. Results show that development of the morphology of flame collision can be distinguished in three stages: independent propagation, strong interaction with flattened interfaces, and corner dynamics after merging of the interfaces. It is further demonstrated that propagation of the flame corner is controlled by the interacting mechanisms of preferential diffusion and kinematic restoration, that vorticity of considerable strength is generated downstream of the corner flame segment, and that the kinetic energy of the flame-generated vorticity is substantial as compared to those of the Kolmogorov eddies such that it could have strong influence on the turbulence energy spectrum and flame burning rate.
KW - Corner dynamics
KW - Flame collision
KW - Flame-generated vorticity
KW - Morphology
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U2 - 10.1016/j.combustflame.2015.10.029
DO - 10.1016/j.combustflame.2015.10.029
M3 - Article
AN - SCOPUS:84960510895
SN - 0010-2180
VL - 167
SP - 444
EP - 451
JO - Combustion and Flame
JF - Combustion and Flame
ER -