Premixed Turbulent Combustion Controlled by Complex Chemical Kinetics

Champion, Michel

doi:10.1080/00102208008952421

Cited by 9 publications

(1 citation statement)

References 15 publications

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“…The turbulent flame thickness is seen to be 5.09 mm, or about one-tenth å=0.09 3/4 k 3/2 / L (9) of the cylinder radius. Champion [32] computed the species concentrations and Thompson et al [33] mea-L =d bore /2, d bore <ä (10) sured species profiles in steady, turbulent burner L =0.2ä, ä <d bore (11) flames. The species profiles they obtained resemble those in Fig.…”

Section: Parametric Runs Of the Programmentioning

confidence: 99%

Computation of flamefront NO emissions from spark ignition engines

Narayan

Rajan

2001

International Journal of Engine Research

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Flamefront NO emissions from spark ignition The Fenimore mechanism [5] is yet another reacengines are estimated in this work using a two-zone thermo-tion pathway that leads to 'prompt' NO formation dynamic combustion model, an unsteady engine flame in a flamefront and also in post-flame gases of very model, the wrinkled laminar flame model of Bray and Moss, rich premixed flames [6]. In all premixed flames, O the k-å theory and simplified flamefront NO chemistry atom concentrations are much above chemical equiwhich has been verified in steady laminar premixed flames. librium levels, augmenting the rates within the The results show that as much as 230 ppm of flamefront NO flamefront of the Zeldovich and N 2 O reaction rates may be formed under stoichiometric engine operating con-[6]. Flamefront NO emissions, including Fenimore's ditions. The present approach is an alternative to the empiriprompt NO, from steady laminar methane/air cal correlations used to compute engine flamefront NO flames have been successfully predicted by a number which are based on highly extrapolated data. of workers [6-9], because of exponential increases in computing capabilities and more accurate chemical Key words: flamefront NO emissions, prompt NO, kinetic data. The flamefront NO mechanism in prespark ignition engine, methane fuel, two-zone engine mixed flames is very complex [6], but has recently combustion model been simplified by a number of workers [9, 10]. It is difficult to predict flamefront NO emissions from turbulent flames because turbulent flame codes cannot incorporate more than a few chemical reac-

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Section: Parametric Runs Of the Programmentioning

confidence: 99%

Computation of flamefront NO emissions from spark ignition engines

Narayan

Rajan

2001

International Journal of Engine Research

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Wall fire close to an horizontal surface: Numerical modelling and experimental validation

1992

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In order to contribute to a better understanding of natural fire configurations, three different experimental arrangements were considered. They simulated, a t laboratory scale, three simple room fire situations.' -3 First, we tested a gas-fueled porous burner simulating a wall fire. Then an insulated floor was placed close to it. Finally the wall and the floor burnt simultaneously. Velocity and turbulence measurements were performed using a two-component laser-doppler velocimetry (LDV) system operating in the forward-scatter mode. Mean gas temperatures were obtained with a 200 p m butt-welded chromel-alumel thermocouple, located 2 mm downstream of the velocity measurement control volume. Simultaneous measurements of two velocity components proved to be very useful, especially in the characterization of the flame structure and of the entrainment process. A simple field model describing strongly buoyant Qiffusion flames is proposed in search of computational economy and a basic understanding of the phenomena involved. Our aim is to analyse the suitability of such a simple model for the description of the mean properties of the flow. This work showed the interaction between the burning wall, the floor and the pool fire, and especially the role played by the large-scale structures characteristic of entrainment and mixing processes in free fires.

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