| Autor: |
Osamu Imamura, Shinji Nakaya, Kazuhiro Akihama, Mitsuhiro Tsue, Hiroshi Yamasaki, Kazuya Iwata |
| Rok vydání: |
2021 |
| Předmět: |
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| Zdroj: |
Proceedings of the Combustion Institute. 38:3651-3659 |
| ISSN: |
1540-7489 |
| Popis: |
Self-sustained oblique detonation behind a spherical projectile formed in a non-uniform H2/O2/Ar mixture was numerically investigated. A hypersonic combustible mixture flow around a 4.76 mm diameter body was modeled to be flowing at 2500 m/s and 100 kPa. The concentration gradient was prescribed applying the Gaussian distribution to hydrogen concentration. Axisymmetric Euler equations including a detailed kinetics of 9 species and 27 elementary reactions were solved with an explicit 2nd-order time integration scheme combined with point implicit method for chemical reaction. Oblique detonation was always obtained when the mixture on the centerline was stoichiometric, as it is for a uniform mixture, and a broader range of equivalence ratio could sustain oblique detonation far from the sphere. Local detonation angle was revealed to reasonably match Chapman-Jouguet analytical solutions with a minor difference attributed to curvature, less reactive composition, and the concentration gradient. Also, a strongly fuel-rich region encountered decoupling of the shock-flame, in which an abrupt deflection of the shock front appeared. These decoupling phenomena can be attributed to a slower kinetics of a less reactive mixture. All of interesting findings in this study will also benefit understanding of various form of detonation in non-uniform mixture taking advantage of the analogy between them. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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