Issue |
J. Chim. Phys.
Volume 83, 1986
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Page(s) | 487 - 498 | |
DOI | https://doi.org/10.1051/jcp/1986830487 | |
Published online | 29 May 2017 |
Determination par spectroscopie infra-rouge de profils de température et de concentrations en OH dans des flammes prémélangées oxycombustibles à la pression atmosphérique
Groupe de Recherche de Chimie Physique de la Combustion, Université de Poitiers, U.A. au C.N.R.S. n° 872, Le Deffend, Mignaloux-Beauvoir, 86800 St Julien l'Ars, France.
Une méthode expérimentale utilisant la spectroscopie d'émission infrarouge a permis la détermination de la température de rotation et des concentrations locales en radicaux hydroxyles dans des flammes prémélangées oxycombustibles brûlant à la pression atmosphérique. Les résultats montrent que l'équilibre est réalisé dans la flamme C2H2-O2, mais probablement pas dans la flamme H2-O2. L'augmentation importante des OH dans les couches extérieures des flammes riches peut être attribuée à la diffusion de l'air environnant.
Abstract
The knowledge of temperature and species-concentration profiles in premixed, laminar flames plays a key role in the development of detailed combustion models. For that purpose an experimental method using infrared emission spectroscopy has been derived, that allows the simultaneous measurement of temperature and OH concentration. Also, from radiation intensity measurements of the (1, 0) band of the rotation-vibration spectrum of OH in its ground state, both the rotational temperature and the concentration of this species in various oxy-fuel flames burning at atmospheric pressure have been determined. The intensities of the lines from quantum numbers N = 15 through N = 18 have been measured. The radial distribution of the temperature and OH concentration was deduced in a zone immediately above the inner cone using the Abel inversion technique for reducing line-probe data. Local experimental values are compared to the computed ones assuming adiabatic conditions. Results show that adiabatic equilibrium is realised just above the inner cone for the C2H2-O2 flame, but probably not for the H2-O2 flame. The high hydroxyl concentration at the flame boundary in the richer flames is greatly influenced by diffusion and entrainment of the surrounding air which gives a post combustion with unburnt fuel.
© Paris : Société de Chimie Physique, 1986