Spatially resolved measurement of OH*, CH*, and C2* chemiluminescence in the reaction zone of laminar methane/air premixed flames

Kojima, Jun; Ikeda, Yuji; Nakajima, Tatsuo

doi:10.1016/s0082-0784(00)80577-9

Cited by 221 publications

(120 citation statements)

References 14 publications

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“…The sequence of the location of the calculated maximum intensities for the OH* and CH* excited radicals, is OH* followed by CH*, as one scans the flame from the reactants to the products. The calculated distance between them agrees well with the experimental results found in the literature [2,24,58].…”

Section: Discussionsupporting

confidence: 89%

“…The experimental uncertainty for the measurements presented in this work was less than ± 5%. Whenever natural gas was used as the fuel instead of pure methane, its composition was: 93.5% CH 4 , 3.5% C 2 H 6 , 0.7% C 3 H 8 , 0.22% C 4 H 10 , 0.065% C 5+ , 1.5% N 2 & 0.5% CO 2 . More details concerning the experiment can be found in [7,26].…”

Section: Selection Of Operating Conditionsmentioning

confidence: 99%

“…It has been used for identification of the reaction zone [2], to compute Rayleigh index maps [3], as a marker of heat release rate [4][5][6], and to measure flame equivalence ratios [7][8][9][10][11][12]. By use of a Cassegrain optics-based Chemiluminescence Sensor (CS), similar to that used by Akamatsu et al [13] & Kojima et al [2], Hardalupas and Orain [7] demonstrated in their chemiluminescence study that the intensity ratio of the two excited radicals OH* and CH* is independent of strain rate in premixed counterflow flames at atmospheric pressure, in contrast to that of OH* and C 2 *, which is a function of strain rate.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Numerical evaluation of equivalence ratio measurement using OH∗ and CH∗ chemiluminescence in premixed and non-premixed methane–air flames

Panoutsos

Hardalupas

Taylor

2009

Combustion and Flame

240

104

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This work presents results from detailed chemical kinetics calculations of electronically excited OH (A 2 Ȉ, denoted as OH*) and CH (A 2 ǻ, denoted as CH*) chemiluminescent species in laminar premixed and non-premixed counterflow methane-air flames, at atmospheric pressure. Eight different detailed chemistry mechanisms, with added elementary reactions that account for the formation and destruction of the chemiluminescent species OH* and CH*, are studied. The effects of flow strain rate and equivalence ratio on the chemiluminescent intensities of OH*, CH* and their ratio are studied and the results are compared to chemiluminescent intensity ratio measurements from premixed laminar counterflow natural gas-air flames. This is done in order to numerically evaluate the measurement of equivalence ratio using OH* and CH* chemiluminescence, an experimental practice that is used in the literature. The calculations reproduced the experimental observation that there is no effect of strain rate on the chemiluminescent intensity ratio of OH* to CH*, and that the ratio is a monotonic function of equivalence ratio. In contrast, the strain rate was found to have an effect on both the OH* and CH* intensities, in agreement with experiment. The calculated OH*/CH* values showed that only five out of the eight mechanisms studied were within the same order of magnitude with the experimental data. A new mechanism, proposed in this work, gave results that agreed with experiment within 30%. It was found that the location of maximum emitted intensity from the excited species OH* and CH* was displaced by less than 65 and 115 ȝm, respectively, away from the maximum of the heat release rate, in agreement with experiments, which is small relative to the spatial resolution of experimental methods applied to combustion applications, and, therefore, it is expected that intensity from the OH* and CH* excited radicals can be used to identify the location of the reaction zone.Calculations of the OH*/CH* intensity ratio for strained non-premixed counterflow methane-3 air flames showed that the intensity ratio takes different values from those for premixed flames, and therefore has the potential to be used as a criterion to distinguish between premixed and non-premixed reaction in turbulent flames.

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Section: Discussionsupporting

confidence: 89%

Section: Selection Of Operating Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical evaluation of equivalence ratio measurement using OH∗ and CH∗ chemiluminescence in premixed and non-premixed methane–air flames

Panoutsos

Hardalupas

Taylor

2009

Combustion and Flame

240

104

View full text Add to dashboard Cite

show abstract

“…The equivalence ratio (in premixed laminar flames) is often estimated by means of the intensity ratio between OH* and CH* chemiluminescence. The CH*/OH* chemiluminescence ratio is found to proportionally increase with equivalence ratio at atmospheric pressures [18,19].…”

Section: Introductionmentioning

confidence: 90%

The influence of charge stratification on the spectral signature of partially premixed combustion in a light-duty optical engine

et al. 2017

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“…In the visible spectrum excited molecular radicals CH* (430 nm) and C2* (Swan system, dominant emissive band head at 473.71 nm and 516.52 nm) produce 'blue' light [9], the intensity of which has been demonstrated to vary with fuel composition, flow rate, and heat release rate [10][11][12]. The ratio of CH*/C2* can be used to determine the local equivalence ratio [13].…”

Section: Introductionmentioning

confidence: 99%

Investigation of ignition process from visible to infrared by a high speed colour camera

Wang

Zheng

Woolley

et al. 2016

Fuel

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Spatially resolved measurement of OH, CH, and C2* chemiluminescence in the reaction zone of laminar methane/air premixed flames

Cited by 221 publications

References 14 publications

Numerical evaluation of equivalence ratio measurement using OH∗ and CH∗ chemiluminescence in premixed and non-premixed methane–air flames

Numerical evaluation of equivalence ratio measurement using OH∗ and CH∗ chemiluminescence in premixed and non-premixed methane–air flames

The influence of charge stratification on the spectral signature of partially premixed combustion in a light-duty optical engine

Investigation of ignition process from visible to infrared by a high speed colour camera

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