Effects of swirl on the stabilization of non-premixed oxygen-enriched flames above coaxial injectors
| Autor: | Degenève, Arthur, Mirat, Clément, Caudal, Jean, Vicquelin, Ronan, Schuller, Thierry |
|---|---|
| Přispěvatelé: | Air Liquide (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Ecole Supérieure d'Electricité - SUPELEC (FRANCE), Université Paris-Saclay (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de Mécanique des Fluides de Toulouse - IMFT (Toulouse, France), Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, 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: | 2019 |
| Předmět: |
Flames
Momentum 020209 energy Mechanical Engineering Mécanique des fluides Energy Engineering and Power Technology Aerospace Engineering Combustion 02 engineering and technology [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] Oxygen Ejectors Fuel Technology 020401 chemical engineering Nuclear Energy and Engineering 0202 electrical engineering electronic engineering information engineering 0204 chemical engineering |
| Zdroj: | Journal of Engineering for Gas Turbines and Power Journal of Engineering for Gas Turbines and Power, American Society of Mechanical Engineers, 2019, 141 (12), pp.121018. ⟨10.1115/1.4045024⟩ |
| ISSN: | 0742-4795 |
| DOI: | 10.1115/1.4045024⟩ |
| Popis: | An experimental study is carried out to analyze the effects of swirl on the structure and stabilization of methane non-premixed oxygen-enriched flames above a coaxial injector in which the two streams are eventually swirled. The mean position of the flame and the liftoff height above the injector lips are investigated with OH* chemiluminescence images. The oxygen enrichment, the momentum flux ratio between the two coflows, the swirl level inside the central jet, and the swirl level in the annular jet are varied over a large range of operating conditions. It is found that, in the absence of swirl in the central stream, the flame is always attached to the lips of the internal injection tube. As the inner swirl level increases, the flame front located at the lips of the internal injection tube disappears. When the annular swirl level is high enough to create a central recirculating bubble, the flame detaches from the nozzle rim and remains lifted at a finite distance above the injector. Increasing the oxygen concentration shifts this transition to smaller momentum flux ratios and smaller annular swirl levels. The liftoff distance can be finely tuned and depends on the inner and outer swirl levels, and on the momentum flux ratio between the two coaxial streams. It is shown that this feature depends neither on the confinement of the injector nor on the thermal stress exerted by the hot burnt gases on the injector back plane. About 1000 configurations were investigated that could be classified into only four distinct stabilization modes, in which the flame structure was shown to follow a similar pathway when the momentum flux ratio between the two streams, the swirl level in the central and external streams, and the quarl angle of the annular stream are varied. It is finally shown how these limits are altered when the oxygen concentration in the annular oxidizer stream is varied from air to oxygen-enriched operation. |
| Databáze: | OpenAIRE |
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