Scaling relations for the length of coaxial oxy-flames with and without swirl
| Autor: | Ronan Vicquelin, Bernard Labegorre, Thierry Schuller, Clément Mirat, Jean Caudal, Arthur Degenève, Paul Jourdaine |
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| Přispěvatelé: | Air Liquide (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de Mécanique des Fluides de Toulouse - IMFT (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Centre de Recherche Claude Delorme [Jouy-en-Josas] (CRCD), Air Liquide [Siège Social], Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Swirl
Materials science 020209 energy General Chemical Engineering Bubble Mécanique des fluides Flow (psychology) Mixing (process engineering) 02 engineering and technology 7. Clean energy 01 natural sciences Methane 010305 fluids & plasmas law.invention [SPI]Engineering Sciences [physics] chemistry.chemical_compound law 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Flame length Physical and Theoretical Chemistry Coaxial jet Scaling ComputingMilieux_MISCELLANEOUS Mechanical Engineering Mechanics Injector Vortex Turbulence chemistry Oxy-combustion Coaxial |
| Zdroj: | Proceedings of the Combustion Institute Proceedings of the Combustion Institute, Elsevier, 2018, ⟨10.1016/j.proci.2018.06.032⟩ |
| ISSN: | 1540-7489 |
| Popis: | An extensive experimental study is carried out to analyze scaling laws for the length of methane oxy-flames stabilized on a coaxial injector. The central methane fuel stream is diluted with N2, CO2 or He. The annular air stream is enriched with oxygen and can be impregnated with swirl. Former studies have shown that the stoichiometric mixing length of relatively short flames is controlled by the mixing process taking place in the vicinity of the injector outlet. This property has been used to derive scaling laws at large values of the stoichiometric mixture fraction. It is shown here that the same relation can be extended to methane oxy-flames characterized by small values of the stoichiometric mixture fraction. Flame lengths are determined with OH* chemiluminescence measurements over more than 1000 combinations of momentum ratio, annular swirl level and composition of the inner and outer streams of the coaxial injector. It is found that the lengths of all the flames investigated without swirl collapse on a single line, whose coefficients correspond to within 15% of flame lengths obtained for fuel and oxidizer streams at much larger stoichiometric mixture fractions. This relation is then extended to the case of swirling flames by including the contribution of the tangential velocity in the flow entrainment rate and is found to well reproduce the mixing degree of the two co-axial streams as long as the flow does not exhibit a vortex breakdown bubble. At higher swirl levels, when the flow features a central recirculation region, the flame length is found to also directly depend on the oxygen enrichment in the oxidizer stream. |
| Databáze: | OpenAIRE |
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