Fluid vibrations in elastic containment structures

The stresses arising in the containment structure of a nuclear reactor caused by shocks arising in the pool of the pressure suppression system due to forced condensation of steam are studied. Bubble collapse in an infinitely extended fluid is analyzed, and the basic equations for the fluid-structure interaction are derived. Numerical calculative methods are presented for circular containments with arbitrary cross sections filled with either compressible or incompressible fluids. A Fourier series development is used to arrive at a plane model and a very compact system of equations which permits individual influences to be efficiently studied. Eigenforms and eigenfrequencies are calculated, showing that compressibility has only a small effect on the behavior of the elastic containment. For the case of a full containment excited by a collapsing bubble, the pressure-time history is calculated for two different bubble models. The numerical and analytical solutions show good convergence.