Modeling of bound hydrodynamic vibrations of fuel assemblies in WWER-440 reactor core

The hydrodynamic coefficients of fuel assemblies influence on each other have been calculated for modeling the bound hydrodynamic vibrations in a fragment of WWER-440 reactor core composed of seven fuel assemblies. The hydrodynamic problem has been solved as a plane problem of FEM. Calculating of the resultant of water pressure on the fuel assemblies during the harmonic motion of one fuel assembly allowed to sequentially determine the hydrodynamic coefficients of influence (1414 matrix) and the total matrix mass. As a result, the initial problem is reduced to the traditional problem of the dynamics of multimass systems.