Study on multilayered liquids sloshing tank subjected to sway and roll excitation

Abstract

Herein, analytical and numerical approaches are used to investigate the interfacial surface elevations by a swaying and rolling tank with multilayered liquids of different densities. The analytical model, formulated using the eigenfunction expansion method based on two-dimensional linear potential theory, incorporates artificial damping to account for energy dissipation due to friction at the walls and bottom. The analytical model is used to predict the wave elevations and hydrodynamic forces on the tank as well as the natural frequencies of multilayered liquids. In parallel, computational fluid dynamics (CFD) is used, which employs quasi-two-dimensional implicit unsteady, incompressible Navier-Stokes equations. The volume of fluids technique is used to track the interfacial surfaces along with high-resolution interface capturing and interface momentum dissipation techniques. The interfacial surface elevations at the tank wall agree well with the analytical and CFD results, with the expected resonant peaks. Fourier analysis estimates added mass and damping coefficients for the three-layered tank from the total force. CFD results for the three-layered liquids exhibit strong nonlinear wave elevations at the interfaces. Power spectral density (PSD) analysis reveals higher harmonics in CFD solutions as tank amplitude increases.