TY - JOUR
T1 - Morphology of wrinkles along the surface of turbulent Bunsen flames - Their amplification and advection due to the Darrieus-Landau instability
AU - Zhang, Meng
AU - Patyal, Advitya
AU - Huang, Zuohua
AU - Matalon, Moshe
N1 - Publisher Copyright:
© 2018 The Combustion Institute.
PY - 2019
Y1 - 2019
N2 - The morphological development of wrinkles along the surface of a Bunsen flame in a weakly-turbulent flow is investigated, with turbulence added solely to disturb the flame front. The resulting flame-flow interactions are examined using a hybrid Navier-Stokes/front-tracking methodology within the context of the hydrodynamic theory. Topological markers based on the skewness of curvature are introduced to distinguish between sub- and super-critical conditions, or the absence/presence of the Darrieus-Landau instability, respectively. We show that for sub-critical conditions disturbances created along the flame surface are dampened when convected downstream along the flame front, and the flame surface is only weakly perturbed. For super-critical conditions, on the other hand, disturbances of the flame front are amplified when advected downstream leading to a highly corrugated surface and a flame brush of increasing thickness. A measure of these dramatic changes is included in the mean local stretch rate which, when properly modulated by a Markstein length, directly affects the turbulent flame speed.
AB - The morphological development of wrinkles along the surface of a Bunsen flame in a weakly-turbulent flow is investigated, with turbulence added solely to disturb the flame front. The resulting flame-flow interactions are examined using a hybrid Navier-Stokes/front-tracking methodology within the context of the hydrodynamic theory. Topological markers based on the skewness of curvature are introduced to distinguish between sub- and super-critical conditions, or the absence/presence of the Darrieus-Landau instability, respectively. We show that for sub-critical conditions disturbances created along the flame surface are dampened when convected downstream along the flame front, and the flame surface is only weakly perturbed. For super-critical conditions, on the other hand, disturbances of the flame front are amplified when advected downstream leading to a highly corrugated surface and a flame brush of increasing thickness. A measure of these dramatic changes is included in the mean local stretch rate which, when properly modulated by a Markstein length, directly affects the turbulent flame speed.
KW - Bunsen flames
KW - Darrieus-Landau instability
KW - Inclined flames
KW - Markstein length
KW - Turbulent premixed flames
UR - http://www.scopus.com/inward/record.url?scp=85049615328&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85049615328&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2018.06.204
DO - 10.1016/j.proci.2018.06.204
M3 - Article
AN - SCOPUS:85049615328
SN - 1540-7489
VL - 37
SP - 2335
EP - 2343
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 2
ER -