Dernières publications de l'équipe

• 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...
  ×Fermer

  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.

  ---

  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⟩

  ---

  Journal: International Journal of Hydrogen Energy

  ---

  Date de publication: 13-10-2025

  ---

  Auteurs:

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

  ---

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

  ---

  Partager le lien de la publication

  ---

  Voir la publication sur Hal
• 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...
  ×Fermer

  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.

  ---

  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⟩

  ---

  Journal: Nuclear Engineering and Design

  ---

  Date de publication: 01-10-2025

  ---

  Auteurs:

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

  ---

  Liste des documents:

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

  ---

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

  ---

  Partager le lien de la publication

  ---

  Voir la publication sur Hal
• 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...
  ×Fermer

  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.

  ---

  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⟩

  ---

  Journal: Combustion and Flame

  ---

  Date de publication: 01-10-2025

  ---

  Auteurs:

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

  ---

  Liste des documents:

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

  ---

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

  ---

  Partager le lien de la publication

  ---

  Voir la publication sur Hal
• 2025
  Xi Deng, Bin Xie, Omar Matar, Pierre Boivin. A novel hybrid approach for accurate simulation of compressible multi-component flows across all-Mach number. Journal of Computational Physics, 2025, 540, pp.114282. ⟨10.1016/j.jcp.2025.114282⟩. ⟨hal-05343677⟩ Plus de détails...
  ×Fermer

  A novel hybrid approach for accurate simulation of compressible multi-component flows across all-Mach number

  Numerical simulation of multi-component flow systems characterized by the simultaneous presence of pressurevelocity coupling and pressure-density coupling dominated regions remains a significant challenge in computational fluid dynamics. Thus, this work presents a novel approach that combines the Godunov-type scheme for high-speed flows with the projection solution procedure for incompressible flows to address this challenge. To simulate compressible multi-component flows, this study employs the homogeneous model and solves its conservative form by the finite-volume method, which enables the application of the one-fluid model solution procedure while satisfying conservation. The proposed hybrid approach begins by splitting the inviscid flux into the advection part and the pressure part. The solution variables are first updated to their intermediate states by solving the advection part with the all-speed AUSM (Advection Upwind Splitting Method) Riemann solver. The advection flux in AUSM is modified to eliminate the pressure flux term that deteriorates the accuracy at the low Mach region. To prevent the advection flux from causing spurious velocities when surface tension is present, the pressure-velocity coupling term is modified to ensure it vanishes at material interfaces. Then, we derive the pressure Helmholtz equation to solve the final pressure and update the intermediate states to the solution variables at the next time step. The proposed hybrid approach retains the upwind property of the AUSM scheme for high Mach numbers while recovering central schemes and the standard projection solution for low Mach limits. We also prove that the proposed hybrid method is capable of solving the stationary contact discontinuity exactly. To accurately resolve the complex flow structures including shock waves and material interfaces without numerical oscillations, a newly proposed homogenous ROUND (Reconstruction Operator on Unified Normalised-variable Diagram) reconstruction strategy is employed in this work. By simulating high-speed compressible multiphase flows and incompressible multiphase flows, this study demonstrates the ability of the proposed method to accurately handle flow regimes across all Mach numbers. Its capability to address multi-physical processes at all Mach numbers is further validated through simulations of nucleate boiling and the Richtmyer-Meshkov instability with cavitation.

  ---

  Xi Deng, Bin Xie, Omar Matar, Pierre Boivin. A novel hybrid approach for accurate simulation of compressible multi-component flows across all-Mach number. Journal of Computational Physics, 2025, 540, pp.114282. ⟨10.1016/j.jcp.2025.114282⟩. ⟨hal-05343677⟩

  ---

  Journal: Journal of Computational Physics

  ---

  Date de publication: 09-08-2025

  ---

  Auteurs:

  • Xi Deng
  • Bin Xie
  • Omar Matar
  • Pierre Boivin

  ---

  Liste des documents:

  • https://hal.science/hal-05343677/file/MachUniformMultiphaseFlows-2.pdf

  ---

  Digital object identifier (doi): http://dx.doi.org/10.1016/j.jcp.2025.114282

  ---

  Partager le lien de la publication

  ---

  Voir la publication sur Hal
• 2025
  Jinhua Lu, Song Zhao, Pierre Boivin. A lattice-Boltzmann inspired finite volume solver for compressible flows. Computers and Mathematics with Applications, 2025, 187, pp.50-71. ⟨10.1016/j.camwa.2025.03.007⟩. ⟨hal-05086335v1⟩ Plus de détails...
  ×Fermer

  A lattice-Boltzmann inspired finite volume solver for compressible flows

  The lattice Boltzmann method (LBM) for compressible flow is characterized by good numerical stability and low dissipation, while the conventional finite volume solvers have intrinsic conversation and flexibility in using unstructured meshes for complex geometries. This paper proposes a strategy to combine the advantages of the two kinds of solvers by designing a finite volume solver to mimic the LBM algorithm. It assumes an ideal LBM that can recover all desired higher-order moments. Time-discretized moment equations with second-order temporal accuracy and physically consistent dissipation terms are derived from the ideal LBM. By solving the recovered moment equations, a finite volume solver that can be applied to nonuniform meshes naturally, enabling body-fitted mass-conserving simulations, is proposed. Numerical tests show that the proposed solver can achieve good numerical stability from subsonic to hypersonic flows, and low dissipation for a long-distance entropy spot convection. For the challenging direct simulations of acoustic waves, its dissipation can be significantly reduced compared with the Lax-Wendroff solver of the same second-order spatial and temporal accuracy, while only remaining higher than that of the LBM on coarse meshes. The analysis implies that approximations of third-order temporal accuracy are required to recover the low dissipation of LBM further.

  ---

  Jinhua Lu, Song Zhao, Pierre Boivin. A lattice-Boltzmann inspired finite volume solver for compressible flows. Computers and Mathematics with Applications, 2025, 187, pp.50-71. ⟨10.1016/j.camwa.2025.03.007⟩. ⟨hal-05086335v1⟩

  ---

  Journal: Computers and Mathematics with Applications

  ---

  Date de publication: 01-06-2025

  ---

  Auteurs:

  • Jinhua Lu
  • Song Zhao
  • Pierre Boivin

  ---

  Liste des documents:

  • https://hal.science/hal-05086335/file/A%20Lattice-Boltzmann%20inspired%20Finite%20Volume%20solver%20for%20compressible%20flow1.pdf

  ---

  Digital object identifier (doi): http://dx.doi.org/10.1016/j.camwa.2025.03.007

  ---

  Partager le lien de la publication

  ---

  Voir la publication sur Hal