Flow-induced vibration and stability of an element model for parallel-plate fuel assemblies

Flow-induced vibration and stabilities of the parallel-plate assemblies are studied theoretically. A model of multi-parallel-beams joined with single-beam is adopted in the theoretical analysis of the natural vibration characteristics of the parallel-plate assemblies. The functions of the dry-modal mode are used as trial functions to solve the equations of the complex-modal mode by the variational method for the natural frequencies and modes of the wet modal. The critical flow velocity and destabilizing deflection are solved by the direct method and the variational method for the stability of the parallel-plate assemblies and the results of the two methods agree with each other. This paper discovers some systemic results from theoretical and numerical analysis, which offers several useful methods and data to the design and safe operation for the fuel element of nuclear reactors.