A Modification of the Linear Theory to Predict Sloshing in the Spent Fuel Pool under High Frequency Seismic Conditions

Sloshing dynamics is critical in the seismic evaluation of nuclear facilities. Several analytical and numerical methods, including analytical solutions, computational fluid dynamics (CFD), and finite element analysis (FEA), have been used to predict fluid behaviors. A linear theory introduced by Faltinsen has been used to predict the behaviors of fluid, as a response to external excitations including seismic waves or ship motions, filling in pools or tanks in mechanical engineering or ocean engineering fields. Previous studies have shown that the analytical solutions using the linear theory are well matched with experimental and numerical results under low frequency excitations. The theory excludes nonlinear factors in fluid dynamics. Free-surface height consists of impulsive and convective components in the linear solution. The amplitude of convective components decreases as the excitation frequency increase, while the amplitude of impulsive component decreases. The linear theory should be modified to predict free-surface height in high frequency excitation conditions. In this study, the linear theory is modified to predict the free-surface in a spent fuel pool model and compared the calculated results using the modified theory to the numerical results using computational fluid dynamics.