TY - GEN
T1 - Influence of the laminar burning velocity on the transfer functions of premixed methane and propane swirl flames
AU - Di Sabatino, Francesco
AU - Guiberti, Thibault
AU - Moeck, J. P.
AU - Roberts, William L.
AU - Lacoste, Deanna
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work is funded by the King Abdullah University of Science and Technology and by the Deutsche Forschungsgemeinschaft through the GECCO project.
PY - 2019/11/5
Y1 - 2019/11/5
N2 - The effects of the laminar burning velocity (SL), on the transfer functions of propane-air and methane-air swirl flames is experimentally investigated. Five equivalence ratios for each fuel are selected, to yield different values of SL. The flame transfer function (FTF), is obtained by comparing the velocity fluctuations of the incoming flow, measured with a hot wire, to the heat release rate oscillations, collecting OH∗ chemiluminescence with a photomultiplier tube. Phase-locked images of OH∗ chemiluminescence are also acquired to analyze the flame dynamics during the forcing cycle. The unforced velocity fields are measured by particle image velocimetry to assess the effects of SL on the flow fields. Changing the laminar burning velocity affects mainly the gain around 176 Hz and 336 Hz. This paper focuses on 336 Hz. The flame vortex roll-up is recognized as a key parameter controlling the gain of the FTF around 336 Hz. The analysis highlights that SL influences the gain response around 336 Hz in two competing ways: first, it enhances the flame vortex roll-up and second, it affects the stabilization distance of the flame, which influences the vortex generated by acoustic forcing.
AB - The effects of the laminar burning velocity (SL), on the transfer functions of propane-air and methane-air swirl flames is experimentally investigated. Five equivalence ratios for each fuel are selected, to yield different values of SL. The flame transfer function (FTF), is obtained by comparing the velocity fluctuations of the incoming flow, measured with a hot wire, to the heat release rate oscillations, collecting OH∗ chemiluminescence with a photomultiplier tube. Phase-locked images of OH∗ chemiluminescence are also acquired to analyze the flame dynamics during the forcing cycle. The unforced velocity fields are measured by particle image velocimetry to assess the effects of SL on the flow fields. Changing the laminar burning velocity affects mainly the gain around 176 Hz and 336 Hz. This paper focuses on 336 Hz. The flame vortex roll-up is recognized as a key parameter controlling the gain of the FTF around 336 Hz. The analysis highlights that SL influences the gain response around 336 Hz in two competing ways: first, it enhances the flame vortex roll-up and second, it affects the stabilization distance of the flame, which influences the vortex generated by acoustic forcing.
UR - http://hdl.handle.net/10754/660633
UR - https://asmedigitalcollection.asme.org/GT/proceedings/GT2019/58615/Phoenix,%20Arizona,%20USA/1066749
UR - http://www.scopus.com/inward/record.url?scp=85075792291&partnerID=8YFLogxK
U2 - 10.1115/GT2019-90870
DO - 10.1115/GT2019-90870
M3 - Conference contribution
SN - 9780791858615
BT - Volume 4A: Combustion, Fuels, and Emissions
PB - American Society of Mechanical Engineers
ER -