Cédric Flageul
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Cédric Flageul has a total of 37 co-authors. Here are the top co-authors by number of shared publications:
Sofiane Benhamadouche
EDF R&D MFEE - Mécanique des Fluides, Energies et Environnement [EDF R & D] = Fluid Mechanics, Energy and Environment [EDF R & D] (France)
5 shared publications- Karine Sartelet
CEREA, Ecole nationale des ponts et chaussées, EDF R&D, Institut Polytechnique de Paris, IPSL, 77455 Marne-la-vallée, France
3 shared publications - Alice Maison
CEREA, École des Ponts, EDF R&D, IPSL, Marne-la-Vallée, France
2 shared publications - Chao Lin
Institute of Industrial Science, The University of Tokyo Tokyo Japan
2 shared publications - Dominique Laurence
The University of Manchester
2 shared publications - Gaëtan Mangeon
CAGIRE - Computational AGility for internal flows sImulations and compaRisons with Experiments (Laboratoire de mathématiques et de leurs applications UMR 5142 CNRS-université de Pau et des pays de l’Adour IPRA, avenue de l’université BP 1155 – 64013 Pau - France)
2 shared publications
Latest Publications
- 9 November 2026
- Published by Elsevier in International Journal of Heat and Fluid Flow
- Vol. 122
High-fidelity simulation of developing mixed convection in a buoyancy-aided vertical pipe flow
- 9 November 2026
- Published by Elsevier in International Journal of Heat and Fluid Flow
- Vol. 122
High-fidelity simulation of developing mixed convection in a buoyancy-aided vertical pipe flow
- Open Access
- 7 July 2026
- Published by Elsevier in SSRN Electronic Journal
A robust and versatile parallel FFT-based mechanical solver for general non-periodic and periodic boundary conditions
General boundary conditions are implemented within a fast Fourier transform framework for linear and non-linear mechanical problems using small or finite transformation formulations. In the context of parallel computing (distributed memory), we present a framework that enables the combination of periodic and non-periodic (Dirichlet or Neumann) boundary conditions. Taking advantage of the link between non-periodic boundary conditions and the symmetries of the relevant components of the fluctuation displacement and stress fields, discrete trigonometric transforms are employed to adapt the classical Moulinec–Suquet fast Fourier transform approach. The present study employs an original displacement-based fixed-point algorithm in combination with a convergence acceleration method in order to solve boundary value problems. Finite difference approaches are used to build the discrete Green operators associated with a pre-conditioner (reference material), whose choice depends on the loading type and the small or finite transformation frameworks. The newly developed double tetrahedron scheme is employed to investigate non-periodic problems. Outcomes are compared to those of the classical hexahedral scheme. The robustness and computational efficiency of the presented parallel solver is demonstrated through numerical experiments of non-trivial loading scenarios (tension, bending, normal-mixed loading, torsion-bending), complex and densely discretized microstructures and diverse behavior laws (elasticity, isotropic plasticity, crystal plasticity), within small and finite transformation frameworks.
- 7 July 2026
- Published by Elsevier in SSRN Electronic Journal
Open AccessA robust and versatile parallel FFT-based mechanical solver for general non-periodic and periodic boundary conditions
General boundary conditions are implemented within a fast Fourier transform framework for linear and non-linear mechanical problems using small or finite transformation formulations. In the context of parallel computing (distributed memory), we present a framework that enables the combination of periodic and non-periodic (Dirichlet or Neumann) boundary conditions. Taking advantage of the link between non-periodic boundary conditions and the symmetries of the relevant components of the fluctuation displacement and stress fields, discrete trigonometric transforms are employed to adapt the classical Moulinec–Suquet fast Fourier transform approach. The present study employs an original displacement-based fixed-point algorithm in combination with a convergence acceleration method in order to solve boundary value problems. Finite difference approaches are used to build the discrete Green operators associated with a pre-conditioner (reference material), whose choice depends on the loading type and the small or finite transformation frameworks. The newly developed double tetrahedron scheme is employed to investigate non-periodic problems. Outcomes are compared to those of the classical hexahedral scheme. The robustness and computational efficiency of the presented parallel solver is demonstrated through numerical experiments of non-trivial loading scenarios (tension, bending, normal-mixed loading, torsion-bending), complex and densely discretized microstructures and diverse behavior laws (elasticity, isotropic plasticity, crystal plasticity), within small and finite transformation frameworks.
- 10 June 2026
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 1036, A65
Policy-based optimisation of spanwise wall oscillation waveforms for dissimilar-heat-transfer enhancement
The application of spanwise wall oscillations (SWO) to turbulent flow control has been largely confined to sinusoidal forcing and drag-reduction objectives; the optimisation of waveform topology across a continuous parameter space, and the application of SWO to dissimilar heat transfer (DHT), wherein the analogy factor $A_n$ quantifies the ratio of thermal to drag enhancement, remain unexplored. A policy-based optimisation framework coupled with implicit large-eddy simulations and Lagrangian-polynomial waveform parameterisation is employed to investigate four optimisation problems at ${\textit{Re}}_\tau = 200$ and ${\textit{Pr}} = 1$ , where $Re$ is the friction Reynolds number and $Pr$ is the Prandtl number. Drag-reduction benchmarks validate the framework and establish that non-sinusoidal waveforms lead to no advantage for net energetic gain, whilst recovering a quasi-plateau topology that outperforms sinusoidal forcing when drag savings alone are maximised. Applied to DHT, waveform optimisation at 25 % reduced amplitude identifies a quasi-plateau configuration that achieves $\overline {A_n} = 1.087$ , matching the sinusoidal optimum ( $\overline {A_n} = 1.091$ ) whilst employing 7.4 % less control energy and producing 37.9 % greater absolute heat-transfer enhancement. These gains establish that sustained Stokes-layer strain during plateau phases governs preferential thermal transport through mechanisms fundamentally distinct from drag reduction. Phase-resolved analysis of the variance modulation reveals that the temperature variance regenerates more effectively and over a broader temporal interval than the velocity variance during the lingering phases, whilst the velocity field is suppressed earlier at the strain reversal. This asymmetric regeneration, hypothesised to originate in the pressure-strain redistribution term present exclusively in the momentum equations, constitutes the phase-resolved fingerprint of Reynolds analogy breaking even at ${\textit{Pr}} = 1$ . Waveform optimisation is thereby established as a superior, energy-efficient alternative to amplitude escalation for thermal management applications such as concentrated solar power receivers.- 10 June 2026
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 1036, A65
Policy-based optimisation of spanwise wall oscillation waveforms for dissimilar-heat-transfer enhancement
The application of spanwise wall oscillations (SWO) to turbulent flow control has been largely confined to sinusoidal forcing and drag-reduction objectives; the optimisation of waveform topology across a continuous parameter space, and the application of SWO to dissimilar heat transfer (DHT), wherein the analogy factor $A_n$ quantifies the ratio of thermal to drag enhancement, remain unexplored. A policy-based optimisation framework coupled with implicit large-eddy simulations and Lagrangian-polynomial waveform parameterisation is employed to investigate four optimisation problems at ${\textit{Re}}_\tau = 200$ and ${\textit{Pr}} = 1$ , where $Re$ is the friction Reynolds number and $Pr$ is the Prandtl number. Drag-reduction benchmarks validate the framework and establish that non-sinusoidal waveforms lead to no advantage for net energetic gain, whilst recovering a quasi-plateau topology that outperforms sinusoidal forcing when drag savings alone are maximised. Applied to DHT, waveform optimisation at 25 % reduced amplitude identifies a quasi-plateau configuration that achieves $\overline {A_n} = 1.087$ , matching the sinusoidal optimum ( $\overline {A_n} = 1.091$ ) whilst employing 7.4 % less control energy and producing 37.9 % greater absolute heat-transfer enhancement. These gains establish that sustained Stokes-layer strain during plateau phases governs preferential thermal transport through mechanisms fundamentally distinct from drag reduction. Phase-resolved analysis of the variance modulation reveals that the temperature variance regenerates more effectively and over a broader temporal interval than the velocity variance during the lingering phases, whilst the velocity field is suppressed earlier at the strain reversal. This asymmetric regeneration, hypothesised to originate in the pressure-strain redistribution term present exclusively in the momentum equations, constitutes the phase-resolved fingerprint of Reynolds analogy breaking even at ${\textit{Pr}} = 1$ . Waveform optimisation is thereby established as a superior, energy-efficient alternative to amplitude escalation for thermal management applications such as concentrated solar power receivers.- 2 April 2026
- Published by Agence Bibliographique de l'Enseignement Supérieur
Création de bases de données fines par simulation directe pour les effets de la turbulence sur les transferts thermiques pariétaux
Cette étude porte sur le transfert thermique pariétal dans un canal plan turbulent. L'étude est théorique et numérique. Nos simulations directes (DNS) sont effectuées avec le code de calcul Incompact3d. On a porté un intérêt particulier aux grandeurs que l'on trouve dans les bilans des flux thermiques turbulents et de la variance de la température : ces données permettent de valider les modèles de type RANS. On analyse également nos simulation à l'aune de statistiques plus fines, telles que les corrélations en 2 points. On distingue 2 traitements de la thermique dans le cas du canal plan turbulent : avec ou sans prise en compte du transfert thermique conjugué (couplage thermique fluide/solide). Pour les cas avec transfert thermique conjugué, on a mis en évidence une condition de compatibilité dans l'espace spectral entre la température et le flux de chaleur à l'interface fluide-solide. En l'absence de transfert thermique conjugué, notre étude se borne aux conditions limites qui sont une combinaison linéaire à coefficients constants de la température et du flux de chaleur à la paroi (Dirichlet, Neumann, Robin). Pour ces conditions aux limites simples, on met en évidence une condition de compatibilité entre les valeurs pariétales de la variance de la température et la partie normale de la dissipation associée. D'une part, cette relation souligne les limites des simulations avec une température ou un flux imposé à la paroi. D'autre part, elle permet de construire des conditions de type Robin sur-mesure qui donnent des résultats proches de ceux obtenus avec transfert thermique conjugué pour la configuration du canal plan turbulent.
- 2 April 2026
- Published by Agence Bibliographique de l'Enseignement Supérieur
Création de bases de données fines par simulation directe pour les effets de la turbulence sur les transferts thermiques pariétaux
Cette étude porte sur le transfert thermique pariétal dans un canal plan turbulent. L'étude est théorique et numérique. Nos simulations directes (DNS) sont effectuées avec le code de calcul Incompact3d. On a porté un intérêt particulier aux grandeurs que l'on trouve dans les bilans des flux thermiques turbulents et de la variance de la température : ces données permettent de valider les modèles de type RANS. On analyse également nos simulation à l'aune de statistiques plus fines, telles que les corrélations en 2 points. On distingue 2 traitements de la thermique dans le cas du canal plan turbulent : avec ou sans prise en compte du transfert thermique conjugué (couplage thermique fluide/solide). Pour les cas avec transfert thermique conjugué, on a mis en évidence une condition de compatibilité dans l'espace spectral entre la température et le flux de chaleur à l'interface fluide-solide. En l'absence de transfert thermique conjugué, notre étude se borne aux conditions limites qui sont une combinaison linéaire à coefficients constants de la température et du flux de chaleur à la paroi (Dirichlet, Neumann, Robin). Pour ces conditions aux limites simples, on met en évidence une condition de compatibilité entre les valeurs pariétales de la variance de la température et la partie normale de la dissipation associée. D'une part, cette relation souligne les limites des simulations avec une température ou un flux imposé à la paroi. D'autre part, elle permet de construire des conditions de type Robin sur-mesure qui donnent des résultats proches de ceux obtenus avec transfert thermique conjugué pour la configuration du canal plan turbulent.
- 5 June 2024
- Published by Elsevier in Atmospheric Environment
- Vol. 333
Impact of gas dry deposition parameterization on secondary particle formation in an urban canyon
- 5 June 2024
- Published by Elsevier in Atmospheric Environment
- Vol. 333
Impact of gas dry deposition parameterization on secondary particle formation in an urban canyon
- 1 January 2023
- Published by Begell House Inc. Publishers
- p. 4
Conjugate heat transfer with different fluid-solid physical properties: a differential flux model based on elliptic blending
A new formulation of the Elliptic Blending Differential Flux Model extended the original model of Dehoux et al.[1] to various wall thermal boundary conditions for the turbulent heat flux and the temperature variance [2]. An assessment of this new model coupled with Conjugate Heat Transfer (CHT) is proposed for several values of fluid-solid thermal diffusivity and conductivity ratios. A careful attention is paid to the discountinuity of the dissipation rate associated with the temperature variance at the fluid-solid interface. The present analysis is supported by the Direct Numerical Simulations of an incompressible channel flow at a friction Reynolds number and a Prandtl number equal to 150 and 0.71, respectively [3].
- 1 January 2023
- Published by Begell House Inc. Publishers
- p. 4
Conjugate heat transfer with different fluid-solid physical properties: a differential flux model based on elliptic blending
A new formulation of the Elliptic Blending Differential Flux Model extended the original model of Dehoux et al.[1] to various wall thermal boundary conditions for the turbulent heat flux and the temperature variance [2]. An assessment of this new model coupled with Conjugate Heat Transfer (CHT) is proposed for several values of fluid-solid thermal diffusivity and conductivity ratios. A careful attention is paid to the discountinuity of the dissipation rate associated with the temperature variance at the fluid-solid interface. The present analysis is supported by the Direct Numerical Simulations of an incompressible channel flow at a friction Reynolds number and a Prandtl number equal to 150 and 0.71, respectively [3].
- 1 January 2023
- Published by Begell House Inc. Publishers
- p. 4
Conjugate heat transfer with different fluid-solid physical properties: a differential flux model based on elliptic blending
A new formulation of the Elliptic Blending Differential Flux Model extended the original model of Dehoux et al.[1] to various wall thermal boundary conditions for the turbulent heat flux and the temperature variance [2]. An assessment of this new model coupled with Conjugate Heat Transfer (CHT) is proposed for several values of fluid-solid thermal diffusivity and conductivity ratios. A careful attention is paid to the discountinuity of the dissipation rate associated with the temperature variance at the fluid-solid interface. The present analysis is supported by the Direct Numerical Simulations of an incompressible channel flow at a friction Reynolds number and a Prandtl number equal to 150 and 0.71, respectively [3].
- 1 January 2023
- Published by Begell House Inc. Publishers
- p. 4
Conjugate heat transfer with different fluid-solid physical properties: a differential flux model based on elliptic blending
A new formulation of the Elliptic Blending Differential Flux Model extended the original model of Dehoux et al.[1] to various wall thermal boundary conditions for the turbulent heat flux and the temperature variance [2]. An assessment of this new model coupled with Conjugate Heat Transfer (CHT) is proposed for several values of fluid-solid thermal diffusivity and conductivity ratios. A careful attention is paid to the discountinuity of the dissipation rate associated with the temperature variance at the fluid-solid interface. The present analysis is supported by the Direct Numerical Simulations of an incompressible channel flow at a friction Reynolds number and a Prandtl number equal to 150 and 0.71, respectively [3].
- Open Access
- 25 March 2022
- Published by MDPI AG in Atmosphere
- Vol. 13 (4) , 527
Parametrization of Horizontal and Vertical Transfers for the Street-Network Model MUNICH Using the CFD Model Code_Saturne
Cities are heterogeneous environments, and pollutant concentrations are often higher in streets compared with in the upper roughness sublayer (urban background) and cannot be represented using chemical-transport models that have a spatial resolution on the order of kilometers. Computational Fluid Dynamics (CFD) models coupled to chemistry/aerosol models may be used to compute the pollutant concentrations at high resolution over limited areas of cities; however, they are too expensive to use over a whole city. Hence, simplified street-network models, such as the Model of Urban Network of Intersecting Canyons and Highways (MUNICH), have been developed. These include the main physico-chemical processes that influence pollutant concentrations: emissions, transport, deposition, chemistry and aerosol dynamics. However, the streets are not discretized precisely, and concentrations are assumed to be homogeneous in each street segment. The complex street micro-meteorology is simplified by considering only the vertical transfer between the street and the upper roughness sublayer as well as the horizontal transfer between the streets. This study presents a new parametrization of a horizontal wind profile and vertical/horizontal transfer coefficients. This was developed based on a flow parametrization in a sparse vegetated canopy and adapted to street canyons using local-scale simulations performed with the CFD model Code_Saturne. CFD simulations were performed in a 2D infinite street canyon, and three streets of various aspect ratios ranging from to were studied with different incoming wind directions. The quantities of interest (wind speed in the street direction and passive tracer concentration) were spatially averaged in the street to compare with MUNICH. The developed parametrization depends on the street characteristics and wind direction. This effectively represents the average wind profile in a street canyon and the vertical transfer between the street and the urban roughness sublayer for a wide range of street aspect ratios while maintaining a simple formulation.- 25 March 2022
- Published by MDPI AG in Atmosphere
- Vol. 13 (4) , 527
Open AccessParametrization of Horizontal and Vertical Transfers for the Street-Network Model MUNICH Using the CFD Model Code_Saturne
Cities are heterogeneous environments, and pollutant concentrations are often higher in streets compared with in the upper roughness sublayer (urban background) and cannot be represented using chemical-transport models that have a spatial resolution on the order of kilometers. Computational Fluid Dynamics (CFD) models coupled to chemistry/aerosol models may be used to compute the pollutant concentrations at high resolution over limited areas of cities; however, they are too expensive to use over a whole city. Hence, simplified street-network models, such as the Model of Urban Network of Intersecting Canyons and Highways (MUNICH), have been developed. These include the main physico-chemical processes that influence pollutant concentrations: emissions, transport, deposition, chemistry and aerosol dynamics. However, the streets are not discretized precisely, and concentrations are assumed to be homogeneous in each street segment. The complex street micro-meteorology is simplified by considering only the vertical transfer between the street and the upper roughness sublayer as well as the horizontal transfer between the streets. This study presents a new parametrization of a horizontal wind profile and vertical/horizontal transfer coefficients. This was developed based on a flow parametrization in a sparse vegetated canopy and adapted to street canyons using local-scale simulations performed with the CFD model Code_Saturne. CFD simulations were performed in a 2D infinite street canyon, and three streets of various aspect ratios ranging from to were studied with different incoming wind directions. The quantities of interest (wind speed in the street direction and passive tracer concentration) were spatially averaged in the street to compare with MUNICH. The developed parametrization depends on the street characteristics and wind direction. This effectively represents the average wind profile in a street canyon and the vertical transfer between the street and the urban roughness sublayer for a wide range of street aspect ratios while maintaining a simple formulation.