Numerical simulations of the turbelence-induced vibrations of a wire-wrapped hexagonal fuel assembly

Research output: Contribution to report/book/conference proceedingsIn-proceedings paper

Authors

Institutes & Expert groups

  • UGent - Universiteit Gent
  • Argonne National Laboratory

Abstract

Currently, the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) is being designed as a prototype for a fast reactor driven by a particle accelerator. The fuel pins will be separated by wire wrappers and they will be cooled with lead-bismuth eutectic (LBE). Due to this construction and the dense fluid, the occurrence of flow-induced vibrations and possible consequences like fretting have to be investigated. In this research, the focus is on the prediction of the vibration spectrum due to the turbulent flow in the core. The methodology consists of four main steps. First, a modal analysis on a single wire-wrapped fuel pin has been performed to determine its eigenfrequencies and damping ratios in air. Second, a computational fluidstructure interaction (FSI) analysis has been performed on a bundle with seven pins. In these simulations, the wire wrappers have been neglected, but this has been compensated by adjusting the material properties of the pins. These simulations resulted in a spectrum of eigenfrequencies and damping ratios of the fuel pins in contact with LBE. As third step, large eddy simulation (LES) of the flow in the reactor core has been performed, including the wire wrappers and assuming a rigid geometry. This step resulted in timedependent pressure distributions on the pin surfaces. The final step is then the calculation of the vibration spectrum, by applying these pressure distributions on structural models of the pins with eigenfrequencies and damping ratios corresponding to the average values of those obtained in the second step. The preliminary results predict contact between the fuel pins.

Details

Original languageEnglish
Title of host publication18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18)
PublisherAmerican Nuclear Society
Pages5092-5102
Number of pages11
StatePublished - 18 Aug 2019
Event2019 - NURETH18 - Portland, United States

Conference

Conference2019 - NURETH18
Abbreviated titleNURETH
CountryUnited States
CityPortland
Period2019-08-182019-08-23
Internet address

Keywords

  • fluid-structure interactions, flow-induced vibrations, turbulence-induced vibrations, Computational Fluid Dynamics

ID: 5468805