Dernières publications de l'équipe

• 2026
  Marc Le Boursicaud, Jean-Louis Consalvi, Pierre Boivin. Prediction of hydrogen–ammonia blends autoignition. Combustion and Flame, 2026, 285, pp.114713. ⟨10.1016/j.combustflame.2025.114713⟩. ⟨hal-05469163⟩ Plus de détails...
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  Prediction of hydrogen–ammonia blends autoignition

  The growing interest in hydrogen as an alternative energy vector has raised new technological challenges, in particular regarding its storage. This has motivated increasing attention to ammonia as a hydrogen carrier. In parallel, the use of hydrogen-ammonia blends as combustible fuels has attracted significant interest, as such mixtures can be easier to handle in some applications than pure hydrogen, while still enabling carbon-free combustion.In this context, the present study focuses on modeling the ignition of arbitrary gaseous hydrogen-ammonia-air blends. First, the minimal chemical description required to accurately capture the ignition delay of these mixtures is identified, revealing three main ignition regimes. Ignition delay formulas are then derived for these regimes by extending methods previously developed for pure hydrogen and syngas. The resulting ignition time expressions are subsequently combined into a unified formulation, valid across a wide range of pressures, temperatures, and fuel compositions. Finally, modifications to a recently published passive scalar model for CFD tools are introduced so as to accurately predict ignition events in hydrogen-ammonia-air mixtures while reducing computational cost. Novelty and

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  Marc Le Boursicaud, Jean-Louis Consalvi, Pierre Boivin. Prediction of hydrogen–ammonia blends autoignition. Combustion and Flame, 2026, 285, pp.114713. ⟨10.1016/j.combustflame.2025.114713⟩. ⟨hal-05469163⟩

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  Journal: Combustion and Flame

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  Date de publication: 01-01-2026

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  Auteurs:

  • Marc Le Boursicaud
  • Jean-Louis Consalvi
  • Pierre Boivin

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  Liste des documents:

  • https://hal.science/hal-05469163/file/NH3_H2_ignition_author.pdf

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  Digital object identifier (doi): http://dx.doi.org/10.1016/j.combustflame.2025.114713

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• 2025
  Ziyin Chen, Song Zhao, Bruno Denet, Christophe Almarcha, Pierre Boivin. A three-dimensional study on premixed flame propagation in narrow channels considering hydrodynamic and thermodiffusive instabilities. Combustion and Flame, 2025, 281, pp.114392. ⟨10.1016/j.combustflame.2025.114392⟩. ⟨hal-05344216⟩ Plus de détails...
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  A three-dimensional study on premixed flame propagation in narrow channels considering hydrodynamic and thermodiffusive instabilities

  In numerical studies of quasi-2D problems, such as laminar flame propagation through a slit, the quasi-2D assumption is commonly applied to simplify the problem. However, the impact of the third dimension (in the thickness between walls) can be significant due to strong curvature. The intrinsic Darrieus-Landau instability, the Saffman-Taylor instability, and the thermodiffusive instability lead to curved flame fronts in both the transverse and normal directions and radically change the global flame speed. This study investigates the interaction of these instabilities and their impact on premixed flames freely propagating in narrow channels. Two lean fuel-air mixtures are considered: one with unity Lewis number Le = 1 and another with Le = 0.5. A single-step Arrhenius-type reaction is used for combustion modeling. Joulin Sivashinsky's model [1], termed the 2D+ model, is implemented to capture the confinement effect due to walls. By comparing 3D Direct Numerical Simulations (DNS) and 2D simulations at unity Le, we find that the 2D+ model accurately reproduces confinement effects for channel width h up to 3.6δ T (δ T : thermal flame thickness), extending the validity of Darcy's law.

  However, for larger h, interactions between flame curvatures in two directions result in higher flame surface increment and consumption speed. Besides, for 3D cases with Le = 0.5, positive curvature regions on the flame front primarily contribute to the global reaction due to the Lewis effect. Statistical studies on flame dynamics between walls in 3D cases are also

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  Ziyin Chen, Song Zhao, Bruno Denet, Christophe Almarcha, Pierre Boivin. A three-dimensional study on premixed flame propagation in narrow channels considering hydrodynamic and thermodiffusive instabilities. Combustion and Flame, 2025, 281, pp.114392. ⟨10.1016/j.combustflame.2025.114392⟩. ⟨hal-05344216⟩

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  Journal: Combustion and Flame

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  Date de publication: 01-11-2025

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  Auteurs:

  • Ziyin Chen
  • Song Zhao
  • Bruno Denet
  • Christophe Almarcha
  • Pierre Boivin

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  Liste des documents:

  • https://hal.science/hal-05344216/file/Clean_CNF-D-25-00700_R2.pdf

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  Digital object identifier (doi): http://dx.doi.org/10.1016/j.combustflame.2025.114392

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• 2025
  Kevin Turgut, Ashwin Chinnayya, Pierre Boivin, Omar Dounia. A simplified thermodynamically-consistent single-step mechanism for hydrogen combustion. International Journal of Hydrogen Energy, 2025, 177, pp.151527. ⟨10.1016/j.ijhydene.2025.151527⟩. ⟨hal-05404957⟩ Plus de détails...
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  A simplified thermodynamically-consistent single-step mechanism for hydrogen combustion

  Effective combustion modeling relies on the precise estimation of hydrogenair combustion characteristics. In this sense, Millán-Merino and Boivin [1] designed a single-step mechanism for hydrogen combustion that accurately recovers the adiabatic flame temperature using a variable stoichiometric coefficient formalism. The present study proposes a drastic simplification of this approach (further reducing computational cost and complexity) and formally clarifies the contribution of the variable stoichiometric coefficients and their evolution across the flame internal structure.

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  Kevin Turgut, Ashwin Chinnayya, Pierre Boivin, Omar Dounia. A simplified thermodynamically-consistent single-step mechanism for hydrogen combustion. International Journal of Hydrogen Energy, 2025, 177, pp.151527. ⟨10.1016/j.ijhydene.2025.151527⟩. ⟨hal-05404957⟩

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  Journal: International Journal of Hydrogen Energy

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  Date de publication: 13-10-2025

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  Auteurs:

  • Kevin Turgut
  • Ashwin Chinnayya
  • Pierre Boivin
  • Omar Dounia

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  Digital object identifier (doi): http://dx.doi.org/10.1016/j.ijhydene.2025.151527

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• 2025
  A. Fayet, Pierre Boivin, J. Perez Manes, S. Mimouni, T. Cadiou. Validation of NEPTUNE_CFD for single-phase natural convection. Nuclear Engineering and Design, 2025, 442, pp.114250. ⟨10.1016/j.nucengdes.2025.114250⟩. ⟨hal-05344238⟩ Plus de détails...
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  Validation of NEPTUNE_CFD for single-phase natural convection

  Computational Fluid Dynamics (CFD) is widely used in nuclear engineering for safety related studies, providing a mechanistic solution approach in support of the system and sub-channel numerical scales applied in the safety demonstration. Co-developed by four of the biggest actors of the French nuclear industry, the NEPTUNE CFD code is specialized in nuclear thermal-hydraulics applications allowing to simulate single and two-phase flows on complex geometries. The increasing protagonism of passive systems in new generation reactors demands specific studies regarding its operation and safety. Passive systems are engineered to rely on natural physical phenomena, such as buoyancy or natural convection and to operate without the need of active mechanical components or external power sources. This paper focuses on the validation of NEPTUNE CFD over experimental data of Qureshi and Gebhart [1] -vertical flat plane immersed in water -and semi-empiric correlations from the literature to simulate single-phase natural convection to validate the use of NEPTUNE CFD for simulating passive systems over a wide range of Rayleigh numbers from laminar to turbulent regimes.

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  A. Fayet, Pierre Boivin, J. Perez Manes, S. Mimouni, T. Cadiou. Validation of NEPTUNE_CFD for single-phase natural convection. Nuclear Engineering and Design, 2025, 442, pp.114250. ⟨10.1016/j.nucengdes.2025.114250⟩. ⟨hal-05344238⟩

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  Journal: Nuclear Engineering and Design

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  Date de publication: 01-10-2025

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  Auteurs:

  • A. Fayet
  • Pierre Boivin
  • J. Perez Manes
  • S. Mimouni
  • T. Cadiou

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  Liste des documents:

  • https://hal.science/hal-05344238/file/validationNeptuneFayet.pdf

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  Digital object identifier (doi): http://dx.doi.org/10.1016/j.nucengdes.2025.114250

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• 2025
  Marc Le Boursicaud, Song Zhao, Jean-Louis Consalvi, Pierre Boivin. Modeling self-ignition of high-pressure hydrogen leaks in confined space. Combustion and Flame, 2025, 280, pp.114386. ⟨10.1016/j.combustflame.2025.114386⟩. ⟨hal-05344209⟩ Plus de détails...
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  Modeling self-ignition of high-pressure hydrogen leaks in confined space

  The numerical study of ignition risk in the event of high-pressure hydrogen leakage presents numerous challenges. The first is to properly simulate the complex multi-dimensional flow, characterized by a hemispherical expanding shock and a contact discontinuity. The second is to accurately resolve the di!usion/reaction interface, which exhibits a very small length scale compared to the jet radius. These challenges were addressed in our previous work (Le Boursicaud et al., Combust. Flame 274, 2025), leading to the development of a reduced-order model capable of e"ciently predicting the risk of self-ignition in the case of high-pressure hydrogen storage leakage for various geometries.

  The present work focuses on extending the previously developed model to account for the e!ects of leakage in confined spaces. These modifications include a simple adjustment of the pseudo-1D model to account for shock reflection, as well as the consideration of entropy jumps occurring during the interaction between the reflected shock wave and the di!usion layer. This work is motivated by the potential increase in ignition risk when leaks occur in confined environments, as opposed to the open environments previously considered (Smygalina and Kiverin, Int. J. Hydrog. Energy 47, 2022).

  Novelty and Significance Statement: This work extends a reduced-order model for shock-induced ignition of high-pressure hydrogen leaks from open to confined environments, capturing key e!ects such as shock reflection and shock-contact interaction. It enables e"cient assessment of ignition risk in scenarios where full-resolution simulations are computationally prohibitive.

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  Marc Le Boursicaud, Song Zhao, Jean-Louis Consalvi, Pierre Boivin. Modeling self-ignition of high-pressure hydrogen leaks in confined space. Combustion and Flame, 2025, 280, pp.114386. ⟨10.1016/j.combustflame.2025.114386⟩. ⟨hal-05344209⟩

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  Journal: Combustion and Flame

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  Date de publication: 01-10-2025

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  Auteurs:

  • Marc Le Boursicaud
  • Song Zhao
  • Jean-Louis Consalvi
  • Pierre Boivin

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  Liste des documents:

  • https://hal.science/hal-05344209/file/article_H2_wall.pdf

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  Digital object identifier (doi): http://dx.doi.org/10.1016/j.combustflame.2025.114386

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  Partager le lien de la publication

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  Voir la publication sur Hal