Self-excited sloshing due to the fluid discharge over a flexible plate weir

This paper presents an analytical model for the self-excited sloshing due to the fluid discharge over a flexible weir, as observed in the cooling circuit of the French fast breeder reactor, Super-Phenix-1. To clarify the instability mechanism, we analyzed the case in which a rectangular reservoir was divided into an upstream and a downstream plenum by a flexible plate weir. The kinematic and dynamic effects of the discharged fluid on downstream plenum sloshing are discussed in details. Calculatiions are presented for the rectangular fluid-structure model with successively increasing fluid level difference between the upstream and downstream plenums, and the instability mechanism is examined.