## Articles de journaux |

Capanna, Roberto; Ricciardi, Guillaume; Sarrouy, Emmanuelle; Eloy, Christophe Experimental study of fluid structure interaction on fuel assemblies on the ICARE experimental facility (Article de journal) Nuclear Engineering and Design, 352 , p. 110146, 2019, ISSN: 0029-5493. (Résumé | Liens | BibTeX | Étiquettes: Coupling, Experimental, Fluid Structure interaction, Fuel assemblies, Seismic excitation) @article{Capanna_2019a, title = {Experimental study of fluid structure interaction on fuel assemblies on the ICARE experimental facility}, author = {Roberto Capanna and Guillaume Ricciardi and Emmanuelle Sarrouy and Christophe Eloy}, url = {http://www.sciencedirect.com/science/article/pii/S002954931930158X}, doi = {10.1016/j.nucengdes.2019.110146}, issn = {0029-5493}, year = {2019}, date = {2019-01-01}, journal = {Nuclear Engineering and Design}, volume = {352}, pages = {110146}, abstract = {Accurate knowledge of the mechanical behaviour of the reactor core is needed to estimate the effects of a seismic excitation on a nuclear power plant. Experimental works are needed in order to validate models and to have a better understanding of involved phenomena. The fuel assemblies, in the reactor core, are subjected to an axial water flow which modifies their dynamical behaviour. In this framework a new experimental facility, ICARE, is designed in order to investigate fluid structure interaction phenomena on half scale fuel assemblies. The design of the ICARE experimental facility allows to emphasise the effects of the coupling between different fuel assemblies due to the presence of the water flow. In this paper a brief review of previous experimental facilities is presented and the new ICARE experimental facility is illustrated. ICARE facility consists in 4 half scale fuel assemblies (2\~{A}2 lattice) in a vertical channel submitted to axial flow; one of the assemblies is excited by an hydraulic jack. The aim of this paper is to discuss the experimental results obtained during four experimental campaigns on the ICARE set-up. First, the mechanical behaviour of a single fuel assembly is analysed, and the effect of different experimental parameters is assessed. Added mass, added damping and added stiffness effects due to the water flow are estimated. Later, the coupling between different assemblies is investigated. The presence of the flow induces hydrodynamic effects on non excited fuel assemblies, both on excitation direction and transversal one. Furthermore the increase of the water flow causes the increase of the coupling forces and gives rise to a static coupling between the assemblies.}, keywords = {Coupling, Experimental, Fluid Structure interaction, Fuel assemblies, Seismic excitation}, pubstate = {published}, tppubtype = {article} } Accurate knowledge of the mechanical behaviour of the reactor core is needed to estimate the effects of a seismic excitation on a nuclear power plant. Experimental works are needed in order to validate models and to have a better understanding of involved phenomena. The fuel assemblies, in the reactor core, are subjected to an axial water flow which modifies their dynamical behaviour. In this framework a new experimental facility, ICARE, is designed in order to investigate fluid structure interaction phenomena on half scale fuel assemblies. The design of the ICARE experimental facility allows to emphasise the effects of the coupling between different fuel assemblies due to the presence of the water flow. In this paper a brief review of previous experimental facilities is presented and the new ICARE experimental facility is illustrated. ICARE facility consists in 4 half scale fuel assemblies (2Ã2 lattice) in a vertical channel submitted to axial flow; one of the assemblies is excited by an hydraulic jack. The aim of this paper is to discuss the experimental results obtained during four experimental campaigns on the ICARE set-up. First, the mechanical behaviour of a single fuel assembly is analysed, and the effect of different experimental parameters is assessed. Added mass, added damping and added stiffness effects due to the water flow are estimated. Later, the coupling between different assemblies is investigated. The presence of the flow induces hydrodynamic effects on non excited fuel assemblies, both on excitation direction and transversal one. Furthermore the increase of the water flow causes the increase of the coupling forces and gives rise to a static coupling between the assemblies. |

## Conférences à comité de lecture |

Capanna, R; Ricciardi, G; Eloy, C; Sarrouy, E Confinement Effects on Added Mass of Cylindrical Structures in a Potential Flow (Inproceedings) ASME 2017 Pressure Vessels and Piping Conference, p. V004T04A038–, 2017, (Waikoloa, Hawaii, USA, July 16–20, 2017). (Résumé | Liens | BibTeX | Étiquettes: Fluid Structure interaction) @inproceedings{Capanna_2017, title = {Confinement Effects on Added Mass of Cylindrical Structures in a Potential Flow}, author = {R. Capanna and G. Ricciardi and C. Eloy and E. Sarrouy}, url = {http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2660538}, doi = {10.1115/PVP2017-65352}, year = {2017}, date = {2017-07-16}, booktitle = {ASME 2017 Pressure Vessels and Piping Conference}, volume = {4}, number = {57977}, pages = {V004T04A038--}, abstract = {Efficient modelling and accurate knowledge of the mechanical behaviour of the reactor core are needed to estimate the effects of seismic excitation on a nuclear power plant. The fuel assemblies (in the reactor core) are subjected to an axial water flow which modifies their dynamical behaviour. Several fluid-structure models simulating the response of the core to a seismic load has been developed in recent years; most of them require high computational costs. The work which is presented here is a first step in order to simplify the fluid forces modelling, and thus to be able to catch the main features of the mechanical behaviour of reactor core with low computational costs. The main assumption made in this work is to consider the fluid flow as an inviscid potential flow. Thus, the flow can be described only using one scalar function (velocity potential) instead of a vector field and strongly simplifies the fluid mechanics equations, avoiding the necessity to solve Navier-Stokes equations. The pressure distribution around a cylinder is first solved in Fourier space for different values of the parameters (wavenumber, confinement size).The method is applied to a simple geometry (cylinder in an axial flow with a variable confinement) in order to test its effectiveness. The empirical model is then compared to simulations and reference works in literature. The configuration with large confinement has been solved, and results were in agreement with Slender Body Theory. The dependency on the confinement size strongly depends on the wavenumber, but in any case added mass increases as the confinement size decreases. Finally, future perspectives to extend the model to a group of cylinders and to improve the model are discussed (i.e. add viscosity to the model).}, note = {Waikoloa, Hawaii, USA, July 16\textendash20, 2017}, keywords = {Fluid Structure interaction}, pubstate = {published}, tppubtype = {inproceedings} } Efficient modelling and accurate knowledge of the mechanical behaviour of the reactor core are needed to estimate the effects of seismic excitation on a nuclear power plant. The fuel assemblies (in the reactor core) are subjected to an axial water flow which modifies their dynamical behaviour. Several fluid-structure models simulating the response of the core to a seismic load has been developed in recent years; most of them require high computational costs. The work which is presented here is a first step in order to simplify the fluid forces modelling, and thus to be able to catch the main features of the mechanical behaviour of reactor core with low computational costs. The main assumption made in this work is to consider the fluid flow as an inviscid potential flow. Thus, the flow can be described only using one scalar function (velocity potential) instead of a vector field and strongly simplifies the fluid mechanics equations, avoiding the necessity to solve Navier-Stokes equations. The pressure distribution around a cylinder is first solved in Fourier space for different values of the parameters (wavenumber, confinement size).The method is applied to a simple geometry (cylinder in an axial flow with a variable confinement) in order to test its effectiveness. The empirical model is then compared to simulations and reference works in literature. The configuration with large confinement has been solved, and results were in agreement with Slender Body Theory. The dependency on the confinement size strongly depends on the wavenumber, but in any case added mass increases as the confinement size decreases. Finally, future perspectives to extend the model to a group of cylinders and to improve the model are discussed (i.e. add viscosity to the model). |

# Publications

## Articles de journaux |

Experimental study of fluid structure interaction on fuel assemblies on the ICARE experimental facility (Article de journal) Nuclear Engineering and Design, 352 , p. 110146, 2019, ISSN: 0029-5493. |

## Conférences à comité de lecture |

Confinement Effects on Added Mass of Cylindrical Structures in a Potential Flow (Inproceedings) ASME 2017 Pressure Vessels and Piping Conference, p. V004T04A038–, 2017, (Waikoloa, Hawaii, USA, July 16–20, 2017). |