Introducing non-linearities in a homogeneous modeling of a PWR core

This article focuses upon a model of a periodic diphasic medium: a periodic beam array in a fluid; this can represent a nuclear reactor core. First, to understand the phenomena involved, the authors study the two sub-systems: a row of beams and a section of a row of beams. Then, they validate a simple fluid model which allows them to determine the important parameters of the fluid-structure interaction: the confinement parameter and of course, the fluid density. Then a homogenization technique is used to model the beam array. Thus, the number of degrees of freedom obtained being sufficiently small, it is possible to perform simulations of this complex system. This model is capable of allowing for beam bending, together with any shocks incurred during important excitations