TY - JOUR
T1 - Vortex-induced extinction behavior in methanol gaseous flames
T2 - 28th International Symposium on Combustion
AU - Santoro, V. S.
AU - Kyritsis, D. C.
AU - Linan, A.
AU - Gomez, A.
N1 - Funding Information:
The authors wish to thank the following colleagues: Mr. Ernst Ebert for the design and construction of the vortex generation system and its retrofitting to the counterflow burner, Mr. Mikhail Noskov for preliminary calculations that enabled us to use HCHO as a flame marker, and, Dr. Adonios N. Karpetis for helping with aspects of the data acquisition. The support of NASA, under the Microgravity Science and Applications Program, Grant No. NAG3-1688 (Mr. Dennis Stocker, Contract Monitor), and of NSF, Grant No. CTS-9904296 (Dr. Farley Fisher, Contract Monitor) is gratefully acknowledged.
PY - 2000
Y1 - 2000
N2 - The extinction behavior of methanol counterflow diffusion flames was analyzed experimentally using a combination of HCHO PLIF and LDV measurements, under conditions in which the extinction was brought about by a vortex generated on the oxidizer side. The flames could withstand instantaneous strain rates an much as 2.5 times larger that the quasi-steady ones. The results was rationalized phenomenologically by comparing the characteristic times of the problem, such as the mechanical time, the chemical time, and the vortex turnover time. Estimates of these times produced the following ordering: τch < τvort < τm. Thus, the vortex introduced an unsteady effect in the outer diffusive-convective layer of the flame, while inner reactive-diffusive layer behaved in a ″quasi-steady″ manner. As a result, the flame was subject to a damped strain rate through the outer layer. The difference between vortex-induced extinction and quasi-steady one was much more modest in terms of instantaneous scalar dissipation rate or Damkoehler number. The temporal history of the strain rate was required to determine the effective strain rate felt by the flame. Original is an abstract.
AB - The extinction behavior of methanol counterflow diffusion flames was analyzed experimentally using a combination of HCHO PLIF and LDV measurements, under conditions in which the extinction was brought about by a vortex generated on the oxidizer side. The flames could withstand instantaneous strain rates an much as 2.5 times larger that the quasi-steady ones. The results was rationalized phenomenologically by comparing the characteristic times of the problem, such as the mechanical time, the chemical time, and the vortex turnover time. Estimates of these times produced the following ordering: τch < τvort < τm. Thus, the vortex introduced an unsteady effect in the outer diffusive-convective layer of the flame, while inner reactive-diffusive layer behaved in a ″quasi-steady″ manner. As a result, the flame was subject to a damped strain rate through the outer layer. The difference between vortex-induced extinction and quasi-steady one was much more modest in terms of instantaneous scalar dissipation rate or Damkoehler number. The temporal history of the strain rate was required to determine the effective strain rate felt by the flame. Original is an abstract.
UR - https://www.scopus.com/pages/publications/0033673890
M3 - Article
AN - SCOPUS:0033673890
SP - 37
EP - 38
JO - International Symposium on Combustion Abstracts of Accepted Papers
JF - International Symposium on Combustion Abstracts of Accepted Papers
IS - A
Y2 - 30 July 2000 through 4 August 2000
ER -