Flame Acceleration and Transition to Detonation (FAsTD) in Narrow Channels – FASTD
FAsTD
The ultimate goal/aim of FAsTD is to facilitate the global energy transition by fostering the role of H2 while understanding, from a fundamental point of view, the risks associated with its widespread use, in particular the risk of deflagration-to-detonation-transition (DDT) in narrow geometries.
The conception of a novel experimental facility to experimentally characterize the 3-D structure of FA and transition-to-detonation in narrow channels
While the scientific community has recognized that the flame topologies just prior to detonation onset, as well as that of the detonation itself is three-dimensional, surprisingly, no experimental setup has been devised that allows for simultaneous visualization of the phenomenon from 2-directions 2, nor any attempt has been made to provide field measurements of gas temperatures/velocities during DDT. Moreover, the development of numerical models that are directly informed from accurately determined experimental data has never been suggested.<br /><br />*Objectives*<br /><br />(1) To build a fully optically accessible experimental facility to unveil the 3-D structure of flame acceleration (FA) and detonation onset (DO), and to demonstrate simultaneous two-direction visualization<br /><br />(2) To develop/devise experimentally informed numerical/mathematical models that provide complementary information that is difficult to obtain experimentally.<br /><br />(3) To assess the applicability of current velocity and gas temperature measurement techniques in DDT scenarios
Successful integration of novel experiments and visualization techniques, numerical simulations and mathematical analysis to give a clearer picture of flame acceleration and detonation onset.
- simultaneous schlieren visualization
- high fidelity numerical simulations
- experimentally informed low-order models
*Experimental facility*
- Mechanical design and characterization of fully optically accessible narrow channel
- Demonstrated the feasibility of simultaneous schlieren visualization and its added value to investigate flame acceleration and DDT
To date, a fully optically accessible channel was built to observe the flame topologies during DDT in smooth narrow channels (1-m long; 1 cm 2 cross-section closed at the ignition end and open at the other end). An optical system allowing simultaneous schlieren visualization from two mutually orthogonal directions was devised, and revealed for the first time, the three-dimensional topologies of an accelerating flame, from ignition to detonation onset, in nitrogen-diluted stoichiometric hydrogen-oxygen mixtures (i.e., 2H2+O2+?N2). The widely accepted symmetric assumptions during the very early stages of propagation were confirmed whereas complex asymmetric structures were unraveled and described during FA and DO. The value of simultaneous two-direction high-speed schlieren visualization in providing unique insight into the true reacting front and wave topologies present during the entire DDT evolution was demonstrated. The schlieren images also reveal that detonation onset also varies as a function of dilution and that different onset types can be observed even for the same dilution level. A conference paper (CP) showing preliminary results was presented at ICHS2021, and a journal paper (JP) with the first set of complete results is currently under review for Combustion and Flame.
*Development of experimentally informed models*
- Experimentally informed 1-D front model to study FA and DO – implemented, validated and tested it. Preliminary results were presented at ICDERS 2022 ; 1 conference paper (CP)
- Reactive Euler Equations (REE) with sources/sinks – developed a versatile numerical tool to study the steady solutions for detonation propagation under the influence of friction, heat and curvature losses ; 1 journal paper (JP), 1 CP, 2 JP under review, 1 JP in preparation,
*Experimental facility*
Next steps : - Build flame topology maps (i) using Helium/Argon as diluents ; (ii) as a function of H2 concentration ; (iii) CH4/H2 blends.
- Push towards more quantitative experimental diagnostics (background oriented schlieren, OH-PLIF, interferometry, etc.)
*Development of experimentally informed models*
Next steps : - extension of front model to detailed chemistry ; transient dynamics with REE and experimentally informed 2D simulations.
*Journal papers*
(1) Veiga-López, F., Faria, L. M., & Melguizo-Gavilanes, J. (2022). In?uence of chemistry on the steady solutions of hydrogen gaseous detonations with friction losses. Combustion and Flame, 240, 112050.
(2) Veiga-Lopez, F., Z. F. Weng, Mével R.,Melguizo-Gavilanes, J. (2022) Influence of low-temperature chemistry on steady detonations with curvature losses, Proceedings of the Combustion Institute, Manuscript No: PROCI-D-22-00272, under review
(3) Z. F. Weng, Veiga-Lopez, F., Melguizo-Gavilanes, J., Mével R. (2022) Effect of ozone addition on curved detonations, Combustion and Flame, Manuscript No: CNF-D-22-00545, under review
(4) Ballossier, Y., Virot, F. & Melguizo-Gavilanes, J., (2022). Flame acceleration and detonation onset in narrow channels: simultaneous schlieren visualization. Combustion and Flame, Manuscript No: CNF-D-22-00802, under review
*Conference papers*
(1) Mejía-Botero, C.C., Veiga-Lopez, F., Melguizo-Gavilanes, J. (2022) Critical diameters for CH4/H2-air mixtures: implications for natural gas pipelines, 14th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosion (ISHPMIE), July 11-15, 2022, Braunschweig, Germany
(2) Melguizo-Gavilanes, J., Bauwens, L. (2022) An experimentally informed 1-D DDT model for smooth narrow channels, accepted for oral presentation, 28th International Colloquium on the Dynamics of Explosions and Reactive Systems, June 19-24, 2022, Napoli, Italy
(3) Veiga-Lopez, F., Chinnayya, A., Melguizo-Gavilanes, J. (2022) A methodology to develop simplified schemes for detonation simulations, accepted for oral presentation, 28th International Colloquium on the Dynamics of Explosions and Reactive Systems, June 19 - 24, 2022, Napoli, Italy
(4) Ballossier, Y., Veiga-Lopez, F., Virot, F., Melguizo-Gavilanes, J. (2021) Three-dimensional structures of N2-diluted stochiometric H2-O2 flames in narrow channels, oral presentation, 9th International Conference on Hydrogen Safety, September 21 - 24, 2021, Edinburgh, Scotland
The materialization of a hydrogen economy calls for practical and fundamental understanding of the risks associated with its production, storage and handling. Accidental combustion events include phenomena such as ignition, flame propagation/acceleration, flame-obstacle interactions, shock formation, shock-flame interactions, transition-to-detonation, and detonation propagation. Among these, deflagration-to-detonation transition (DDT) is the most fascinating. From a scientific viewpoint, DDT is an outstanding, physics-rich fundamental problem in combustion. From a practical viewpoint, it is important to understand DDT to develop engineering correlations and simulation tools that can be applied to propulsion, and the prevention/mitigation of explosions. To answer fundamental questions about DDT and examine the details of the process, an in-depth combined experimental, numerical and theoretical effort is needed. A detailed account of the plan to tackle this problem is included here.
Project coordination
Josué MELGUIZO GAVILANES (Institut P' : Recherche et Ingénierie en Matériaux, Mécanique et Energétique)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partner
Pprime Institut P' : Recherche et Ingénierie en Matériaux, Mécanique et Energétique
Help of the ANR 299,279 euros
Beginning and duration of the scientific project:
November 2020
- 48 Months
