Hydraulic instability of flat parallel plate assemblies

Numerical methodology for fluid-structure interaction analysis of nuclear fuel plates under axial flow conditions

3D fluid-solid coupling simulation for plate-type nuclear fuel assemblies under the irradiation condition

A three-dimensional T-shaped flexible beam deformation was investigated using model experiments and numerical simulations. In the experiment, a beam was placed in a recirculating water channel with a steady uniform flow in the inlet. A high-speed camera system (HSC) was utilized to record the T-shaped flexible beam deformation in the cross-flow direction. In addition, a two-way fluid-structure interaction (FSI) numerical method was employed to simulate the deformation of the T-shaped flexible beam. A system coupling was used for conjoining the fluid and solid domain. The dynamic mesh method was used for recreating the mesh. After the validation of the three-dimensional numerical T-shaped flexible solid beam with the HSC results, deformation and stress were calculated for different Reynolds numbers. This study exhibited that the deformation of the T-shaped flexible beam increases by nearly 90% when the velocity is changed from 0.25 to 0.35 m/s, whereas deformation of the T-shaped flexible beam decreases by nearly 63% when the velocity is varied from 0.25 to 0.15 m/s.

https://www.mdpi.com/2077-1312/8/9/714/pdf

Three-Dimensional Fluid-Structure Interaction Case Study on Elastic Beam

Numerical analysis on stability of nuclear fuel plates with inlet support comb

The use of parallel plate-type fuel assemblies is common in nuclear research reactors. One of the main problems of this fuel element configuration is the hydroelastic instability of the plates caused by the high flow velocities. The current work is focused on the hydrodynamic characterization of coolant channels typical of a flat-plate fuel element, using a numerical model developed with the commercial code ANSYS CFX. Numerical results are compared to accurate analytical solutions, considering two turbulence models and three different fluid meshes. For this study, the results demonstrated that the most suitable turbulence model is the k - e model. The discretization error is estimated using the Grid Convergence Index method. Despite its simplicity, this model generates precise flow predictions.

https://www.sbpr.org.br/revista/index.php/REVISTA/article/download/621/495

Simplified CFD model of coolant channels typical of a plate-type fuel element: an exhaustive verification of the simulations

http://10.40.40.102:8080/xmlui/bitstream/123456789/29210/1/24999.pdf

One-way fluid-structure interaction model to study the influence of the fluid velocity and coolant channel thickness on the stability of nuclear fuel plates

The improvement in the efficiency and safety aspects of compact nuclear reactors is directly linked to innovations in fuels and in the geometry of fuel elements (F.E), as is the case of plate-type fuel elements. From the mechanical viewpoint, to ensure that the structure of a fuel element is safe to operate in a compact PWR reactor is important to confirm that it meets the functional design requirements for structures of this type and application, present in ANSI/ANS-57.5-1996 and, also, that the stresses resulting from the loads imposed are less than the permissible mechanical limits for their structural materials, in accordance with ASME III, division 1, subsection NB. In order to develop a methodology of mechanical analysis to verify compliance with the criteria of the cited standards, a numerical model of a plate-type fuel element was developed, taking into consideration the main active loads admitted from the full power operation event belonging to the normal operating condition of a compact PWR type nuclear reactor. The results of the analyses demonstrated that the fuel element designed did not show signs of mechanical failure with respect to the modes of plastic collapse and excess of mechanical deformation.

Javier González Mantecón

Papers

Numerical methodology for fluid-structure interaction analysis of nuclear fuel plates under axial flow conditions

Numerical analysis on stability of nuclear fuel plates with inlet support comb

Simplified CFD model of coolant channels typical of a plate-type fuel element: an exhaustive verification of the simulations

One-way fluid-structure interaction model to study the influence of the fluid velocity and coolant channel thickness on the stability of nuclear fuel plates

Preliminar mechanical evaluation of the structure of a nuclear plate-type fuel element