Laser-induced fluorescence measurements of formaldehyde in a methane/air diffusion flame

Harrington, Joel E.; Smyth, Kermit C.

doi:10.1016/0009-2614(93)85265-p

Cited by 104 publications

(35 citation statements)

References 18 publications

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“…Recalling a per-pulse-power P of roughly 1 mJ/10 ns = 0.1 MW and a linewidth of 1.8 cm −1 , the spectral intensity is found to be on the order of I ν = I/∆ν = 8 · 10 6 m −2 × 0.1 MW/1.8 cm −1 ∼ 10 8 W/cm 2 cm −1 . It is thus unlikely that saturation has occurred in the present experiment since this value is significantly lower than saturation intensities reported by other authors [17,18]. In retrospect, this justifies the linear regime assumption implied by Equation (1).…”

Section: Lif Correctionssupporting

confidence: 77%

“…The quenching rate Q = i n i σ i v i in turn is a function of composition n i , the quenching cross-section σ i and the relative molecular velocity v i = f (T ) of all possible collision partners. Though Harrington and Smyth [17] state that the Boltzmann dilution is by far the larger correction term, the body of literature of fundamental quenching parameters in the appropriate temperature, pressure and composition space is rather scarce. Several groups [25,26,27,23,28] have measured effective fluorescence lifetimes τ eff in flames and generally find a monotonically decreasing lifetime along the reaction coordinate, roughly described by a T −1 relation.…”

Section: Lif Correctionsmentioning

confidence: 99%

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Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Schwarz

Geske

Goldsmith³

et al. 2014

Combustion and Flame

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A versatile flow-reactor design is presented that permits multi-species profile measurements under industrially relevant temperatures and pressures. The reactor combines a capillary sampling technique with a novel fiber-optic Laser-Induced Fluorescence (LIF) method. The gas sampling provides quantitative analysis of stable species by means of gas chromatography (i.e. CH 4 , O 2 , CO, CO 2 , H 2 O, H 2 , C 2 H 6 , C 2 H 4 ), and the fiber-optic probe enables in situ detection of transient LIF-active species, demonstrated here for CH 2 O. A thorough analysis of the LIF correction terms for the temperature-dependent Boltzmann fraction and collisional quenching are presented. The laminar flow reactor is modeled by solving the two-dimensional Navier-Stokes equations in conjunction with a detailed kinetic mechanism. Experimental and simulated profiles are compared. The experimental profiles provide much needed data for the continued validation of the kinetic mechanism with respect to C 1 and C 2 chemistry; additionally, the results provide mechanistic insight into the reaction network of fuel-rich gas-phase methane oxidation, thus allowing optimization of the industrial process.

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Section: Lif Correctionssupporting

confidence: 77%

Section: Lif Correctionsmentioning

confidence: 99%

Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Schwarz

Geske

Goldsmith³

et al. 2014

Combustion and Flame

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show abstract

“…Consequently, the third harmonic of a Nd:YAG laser, 355 nm and 120 mJ/pulse of energy, was used to excite the tail of the transition 1 4 0 in the Ã 1 A 2 ← X 1 A 1 band of HCHO, as in Ref. [19]. The resulting signal was detected using a gated single-stage image intensifier coupled to a CCD (Santa Barbara Instrument Group ST6B).…”

Section: Methodsmentioning

confidence: 99%

Propagation of edge flames in counterflow mixing layers: Experiments and theory

Santoro

Liñán

Gomez

2000

Proceedings of the Combustion Institute

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Edge flames were investigated in a methane/O 2 /N 2 counterflow diffusion flame burner. In a typical experiment, a stable counterflow diffusion flame in an axysymmetric configuration was perturbed by lowering the relevant Damkö hler number slightly below the extinction value, Da ext . As a result, the flame extinguished in the vicinity of the burner axis where conditions were uniform. An edge flame extinction front quickly propagated in the radial direction, turned into an ignition edge flame, and eventually stabilized as a standing triple flame at a radial position larger than the burner radius. This sequence of events resulted from an increase of Da as a function of the radial direction, consequent to a decrease in the strain rate in the radial direction. The edge flame propagation velocity in the ignition mode was measured for propagating edge flames at moderate Da and for standing triple flames at large Da, using a combination of laser Doppler velocimetry of seeded particles, formaldehyde planar laser-induced fluorescence, and natural chemiluminescence imaging. The propagation velocity, nondimensionalized with the premixed laminar flame speed of the unburned stoichiometric mixture, was correlated with Da. The latter was calculated using a thermal diffusive model and velocity measurements. The nondimensional velocity reached a value of 2.6 at large Da, in good agreement with the estimated square root of the ratio of the unburned gas density to the burned gas density, as suggested by scaling considerations.

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“…In most cases, high pulse energies and tunable lasers are required for planar applications. Up to now, tunable excimer lasers [4][5][6][7], frequency doubled Nd:YAG lasers [8,9], nonlinear mixing techniques [10] or dye lasers [9,10] are applied under laboratory conditions for the LIF detection e.g. of formaldehyde.…”

Section: Advanced Disk Laser (Adl)-a Novel Solid State Khz Laser Systemmentioning

confidence: 99%

Investigation of droplet ignition under microgravity conditions using laser-based techniques—an overview

Burkert¹,

Paa²,

Schmidl³

et al. 2004

Acta Astronautica

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Laser-induced fluorescence measurements of formaldehyde in a methane/air diffusion flame

Cited by 104 publications

References 18 publications

Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Propagation of edge flames in counterflow mixing layers: Experiments and theory

Investigation of droplet ignition under microgravity conditions using laser-based techniques—an overview

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