High-speed OH-PLIF imaging of extinction and re-ignition in non-premixed flames with various levels of oxygenation

Juddoo, Mrinal; Masri, Assaad R.

doi:10.1016/j.combustflame.2011.02.003

Cited by 71 publications

(55 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Essentially, three-dimensional flow effects on flame re-ignition exist in turbulent jet flames [7,60], let alone in swirling flows with strong tangential motion. Indeed, they have been observed in the measurements of the current investigated swirl flames [15] and also appears in a partially pre-mixed swirl burner [61].…”

Section: Fig 10mentioning

confidence: 99%

Prediction of Global Extinction Conditions and Dynamics in Swirling Non-premixed Flames Using LES/CMC Modelling

Zhang

Mastorakos

2015

Flow Turbulence Combust

View full text Add to dashboard Cite

The Large Eddy Simulation (LES)/three-dimensional Conditional Moment Closure (CMC) model with detailed chemistry is applied to predict the operating condition and dynamics of complete extinction (blow-off) in swirling non-premixed methane flames. Using model constants previously selected to provide relatively accurate predictions of the degree of local extinction in the piloted jet flames Sandia D−F, the error in the blow-off air velocity predicted by LES/3D-CMC in short, recirculating flames with strong swirl for a range of fuel flow rates is within 25 % of the experimental value, which is considered a new and promising result for combustion LES that has not been applied before for the prediction of the whole blow-off curve in complex geometries. The results also show that during the blow-off transient, the total heat release gradually decreases over a duration that agrees well with experiment. The evolution of localized extinction, reactive scalars and scalar dissipation rate is analyzed. It has been observed that a consistent symptom for flames approaching blow-off is the appearance of high-frequency and high-magnitude fluctuations of the conditionally filtered stoichiometric scalar dissipation rate, resulting in an increased fraction of local extinction over the stoichiometric mixture fraction iso-surfaces. It is also shown that the blow-off time changes with the different blow-off conditions.

show abstract

Section: Fig 10mentioning

confidence: 99%

Prediction of Global Extinction Conditions and Dynamics in Swirling Non-premixed Flames Using LES/CMC Modelling

Zhang

Mastorakos

2015

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…in reacting flows is critical for understanding the performance and emissions of powergeneration and propulsion systems. Recently, several research groups have employed highrepetition-rate planar laser-induced fluorescence (PLIF) to investigate combustion intermediates in turbulent reacting flows using continuously pulsed diode-pumped solid state (DPSS) laser technology [1][2][3][4][5][6][7]. Laser system requirements include tunable ultraviolet (UV) output, narrow spectral bandwidth for efficient frequency conversion and excitation of combustion intermediates, high repetition rate for investigation of transient phenomena, short pulse width for discrimination against background interferences, and high pulse energies for planar measurements.…”

Section: Introductionmentioning

confidence: 99%

“…The low pulse energy ultimately restricts the number of flow parameters that can be measured and inhibits the use of diagnostic techniques such as Raman scattering, Rayleigh scattering, laser-induced incandescence, and PLIF of some key fuel tracers and combustion species. Hence, only a few combustion species have been investigated, and the maximum repetition rate is typically ~10 kHz because of the limited laser energy of current laser hardware [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…This technology has been demonstrated for high-speed measurements of temperature [13]; mixture fraction [14]; PLIF of OH [10,15], NO [12,16,17], CH [18][19][20], and CH 2 O [21,22]; and Raman line imaging of O 2 , N 2 , CH 4 , and H 2 [23], with measurements ranging from 1 kHz to 1 MHz. One approach to burst-mode operation is to utilize multiple oscillator-amplifier chains in a parallel configuration, allowing up to eight high-energy pulses in a time-correlated sequence [15].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

All-diode-pumped quasi-continuous burst-mode laser for extended high-speed planar imaging

Slipchenko¹,

Miller²,

Roy³

et al. 2013

Opt. Express

View full text Add to dashboard Cite

An all-diode-pumped, multistage Nd:YAG amplifier is investigated as a means of extending the duration of high-power, burst-mode laser pulse sequences to an unprecedented 30 ms or more. The laser generates 120 mJ per pulse at 1064.3 nm with a repetition rate of 10 kHz, which is sufficient for a wide range of planar laser diagnostics based on fluorescence, Raman scattering, and Rayleigh scattering, among others. The utility of the technique is evaluated for image sequences of formaldehyde fluorescence in a lifted methane-air diffusion flame. The advantages and limitations of diode pumping are discussed, along with long-pulse diode-bar performance characteristics to guide future designs. Keywordsfluorescence, laser diagnostics, methane, Q switched lasers, diode-pumping, future designs, image sequence, laser pulse sequences, long pulse, methane-air diffusion flames, performance characteristics, planar imaging Disciplines Mechanical Engineering CommentsThis article is from Optics Express 21 (2013) Abstract: An all-diode-pumped, multistage Nd:YAG amplifier is investigated as a means of extending the duration of high-power, burstmode laser pulse sequences to an unprecedented 30 ms or more. The laser generates 120 mJ per pulse at 1064.3 nm with a repetition rate of 10 kHz, which is sufficient for a wide range of planar laser diagnostics based on fluorescence, Raman scattering, and Rayleigh scattering, among others. The utility of the technique is evaluated for image sequences of formaldehyde fluorescence in a lifted methane-air diffusion flame. The advantages and limitations of diode pumping are discussed, along with long-pulse diode-bar performance characteristics to guide future designs.

show abstract

“…An experimental study based on high-speed images of OH planar loser induced fluorescence technique of a turbulent diffusion flame of a compressed natural gas (CNG) conducted by Juddoo and Marsi [6] identified three types of structures, common to all studied flames: 'breaks', 'closures' and 'growing kernels'. Events of 'breaks' are counterbalanced by the occurrence of 'closures' which reconnect the flame sheet and maintain stable combustion particularly in the upstream regions of flames.…”

Section: Introductionmentioning

confidence: 99%

The dilution effect on the extinction of wall diffusion flame

Ghiti¹

2014

Archives of Thermodynamics

View full text Add to dashboard Cite

The dynamic process of the interaction between a turbulent jet diffusion methane flame and a lateral wall was experimentally studied. The evolution of the flame temperature field with the Nitrogen dilution of the methane jet flame was examined. The interaction between the diffusion flame and the lateral wall was investigated for different distance between the wall and the central axes of the jet flame. The dilution is found to play the central role in the flame extinction process. The flame response as the lateral wall approaches from infinity and the increasing of the dilution rate make the flame extinction more rapid than the flame without dilution, when the nitrogen dilution rate increase the flame temperature decrease.

show abstract

High-speed OH-PLIF imaging of extinction and re-ignition in non-premixed flames with various levels of oxygenation

Cited by 71 publications

References 41 publications

Prediction of Global Extinction Conditions and Dynamics in Swirling Non-premixed Flames Using LES/CMC Modelling

Prediction of Global Extinction Conditions and Dynamics in Swirling Non-premixed Flames Using LES/CMC Modelling

All-diode-pumped quasi-continuous burst-mode laser for extended high-speed planar imaging

The dilution effect on the extinction of wall diffusion flame

Contact Info

Product

Resources

About