Problem description: Fluid-structure interactions in nuclear reactor cores are a result of mechanisms occurring at different space scales. The component scale represents the global flow inside the core and is generally simulated though porous media methods. The local scale represents the fuel assembly: it requires CFD scale-resolving methods to calculate consistent fluid forces on the structures, and it features a certain degree of fluid-structure coupling. With the goal of performing multi-scale simulations of a core, the local scale requires the generation of boundary conditions from the component scale. This can be achieved only by a synthetic generation of turbulence, based on the flow results at the component scale. However, the porous media approach used at the component scale does not contain details on the turbulent quantities: the development of new numerical methods is required for generating consistent synthetic turbulence in this configuration.
Objectives:
1. Identify proper hybrid URANS/LES approaches for fuel assembly vibration related issues
2. Identify available turbulence parameters in porous media methods and explore bottom-up scaling approaches
3. Develop a turbulence synthesization method applicable to any fuel array inside a core
Expected results:
1. A novel approach for fluid-induced vibration analysis based on a multi-scale method
2. Clarify the key parameters to generate proper turbulence-resolved boundary conditions in the specific configuration studied
3. Validate the new methods on available experimental configurations