Assessment of Halon-free agents for fire safety application in aircraft propulsion system
Notice bibliographique
Résumé
Abstract Halon 1301 is an effective total flooding fire suppression agent which is widely employed in aircraft cargo and propulsion systems for emergency fire scenarios. The production of Halon 1301 was banned by the Montreal Protocol in 1994 due to its environmental impact on ozone depletion and long atmospheric lifetime. Thus, a credible alternative is required for fire safety application on-board aircrafts. This study forms a follow-up to the work published by A. Dinesh et.al [14] and M. Diakostefanis et.al [16] which studied halon-free fire suppression in aircraft cargo bay through CFD and experimental validation respectively. Due to constraints in cost and logistics of testing fire suppression in a gas turbine engine, a computer modelled fire zone of a hypothetical high-bypass turbofan engine was used to simulate and evaluate the fire suppression performance of three Halon-free agents - HFC-125, HFC-227ea and FIC-13I1. Halon 1301 was also simulated to provide baseline comparison to the alternative agents. The capacity to inert was based on the distribution of agent concentrations subjected to a heptane-based fuel fire. Simulations were conducted at ISASLS and 40,000 feet to represent the engine’s operating environment. Overall, it was found that HFC-125 and HFC-227ea satisfactorily suppressed fire at both ambient scenarios. It was found that agent density and suppression concentration significantly influenced the agent’s ability to mix with ambient air and flood the fire zone. Density of the agent combined with higher inertion concentrations also influenced formation of localised recirculation zones which influenced mixture distribution in the fire zone. The simulations enabled identification of individual changes to agent flow characteristics at different operating conditions and demonstrated the performance criteria of Halon 1301 along with the proposed alternative agents for successful fire suppression. Through this study, it was found that all the agents except FIC-13I1 passed the minimum suppression criteria making HFC-125 and HFC-227ea suitable agents for replacement of Halon 1301. The failure of FIC-13I1 was attributed to the complex design in fire zone and could be overcome by considering a higher factor of safety for this design and injecting higher mass flow rate of the agent into the fire zone. The outcome of this study proposes further work to be carried out through experimental validation of the CFD simulations which will be key to progress the technology to higher TRL and meet aviation certification requirements. Further work may also explore blended agent configurations to tailor the agent characteristics to meet suppression requirements for maintaining safety and reliability of the system.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,004 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».