Modelling the dynamical behaviour of nuclear reactor fuel assemblies

The computation of the motion of fuel rods in a nuclear reactor core is generally difficult because the number of elements is very large. This paper is devoted to an homogenization process likening the fluid-tube-spacer system to an equivalent homogeneous medium for which the constitutive laws are derived. It is shown how non-linearity (non-linear spacers, shocks) can be taken into account. Some numerical computation schemes are evoked. (orig.)