Effect of external periodic excitation on a swirling suspended flame

Алексеенко, С. В.; Дулин, В. М.; Kozorezov, Yu. S.; Маркович, Д. М.

doi:10.1134/s1063785011030187

Cited by 4 publications

(2 citation statements)

References 4 publications

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“…The frequency was selected to be below that of the vortex core precession that determined coherent dynamics of the unforced flow in the nonreacting and reacting cases. This study complements a recent publication by Alekseenko et al (2011a), where a significant forcing effect on the flame was documented. The present article discusses in detail the observed effects of an increase of the overall combustion rate and suppression of the vortex core precession near the burner on the basis of stereo PIV measurements and CH Ã chemiluminescence imaging.…”

Section: Introductionsupporting

confidence: 90%

Effect of High-Amplitude Forcing on Turbulent Combustion Intensity and Vortex Core Precession in a Strongly Swirling Lifted Propane/Air Flame

Алексеенко

Дулин

Kozorezov

et al. 2012

Combustion Science and Technology

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The present work reports stereoscopic particle image velocimetry (PIV) measurements in a strongly swirling nonreacting jet and partially premixed lifted flame. The spatial distributions of the average velocity and components of turbulent kinetic energy were calculated from the measured ensembles of the instantaneous velocity fields. A pronounced bubble-type vortex breakdown was observed for the studied flows. Based on proper orthogonal decomposition (POD) of the PIV data and on estimates of velocity fluctuation spectra by a laser Doppler velocimetry (LDV) probe, it was concluded that the combustion did not fundamentally affect the type of coherent structures in the strongly swirling flow: a pair of secondary helical vortices was induced by a precessing vortex core in both cases. Because a strongly swirling jet flow is usually insensitive to weak forcing, strong perturbations were superimposed on the flow bulk velocity to force the formation of ring-like vortices in the flow and to investigate the possible outcomes on the turbulent combustion process. The forcing frequency was below that of the precession. Based on the CH Ã chemiluminescence signal, it was observed that the forcing provided an increase in the turbulent combustion rate near the flame onset, as the entrainment of ambient air to the rich mixture must have increased. Moreover, for a forcing amplitude typically above the magnitude of reverse flow inside the bubble-type recirculation zone, a dramatic suppression of the vortex core precession took place in the reacting case. This effect was accompanied by a quasi-periodical vanishing of the recirculation zone due to interaction of the forced ring-like vortices with the lifted flame.

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Section: Introductionsupporting

confidence: 90%

Effect of High-Amplitude Forcing on Turbulent Combustion Intensity and Vortex Core Precession in a Strongly Swirling Lifted Propane/Air Flame

Алексеенко

Дулин

Kozorezov

et al. 2012

Combustion Science and Technology

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“…In [3] analytically, and in [4] experimentally, influence of acoustic gas oscillations on the flame propagation in the vertical direction is shown. In [5] the possibility of stabilizing and increasing the intensity of turbulent combustion of methane-air mixture in the flare with the help of external oscillations is shown. In [6] acoustic influence on the area of diffusive jet combustion of methane in air made it possible to reduce the content of soot and nitrogen oxides in the combustion products.…”

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confidence: 99%

Influence of acoustic oscillations on the speed of a cellular hydrogen-air flame in a horizontal channel

Volodin

Golub

Elyanov

2022

Technical Physics Letters

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The results of an experimental investigation of the effect of acoustic oscillations with a frequency of 250-7000 Hz and an intensity of 105 dB on the dynamics of the acceleration of a hydrogen-air flame in an open channel are presented. Dependences of the position of the flame front and cell sizes were obtained from shadow photographs at different frequencies of acoustic oscillations. The frequency values when the average flame speed increases up to 3 times are found. Acoustic action with a frequency of 250 Hz leads to a slight decrease in the speed of the flame. Keywords: Hydrogen, duct combustion, acoustic impact, cellular flame.

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Concentrated air and fire vortices: Physical modeling (a Review)

Varaksin

2016

High Temp

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Effect of external periodic excitation on a swirling suspended flame

Cited by 4 publications

References 4 publications

Effect of High-Amplitude Forcing on Turbulent Combustion Intensity and Vortex Core Precession in a Strongly Swirling Lifted Propane/Air Flame

Effect of High-Amplitude Forcing on Turbulent Combustion Intensity and Vortex Core Precession in a Strongly Swirling Lifted Propane/Air Flame

Influence of acoustic oscillations on the speed of a cellular hydrogen-air flame in a horizontal channel

Concentrated air and fire vortices: Physical modeling (a Review)

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