Numerical Computation of Hydrodynamic Loads on Walls of a Rigid Rectangular Tank Due to Large Amplitude Liquid Sloshing


Abstract: Liquid sloshing in a moving partially filled rectangular tank have been investigated. Sloshing in a rectangular tank is a non-linear phenomenon. When the amplitude of tank oscillation is large, two types of non-linearities are present. One occurs at the free surface due to the large fluid motion. The other occurs at the fluid-tank interface. A numerical algorithm based on the volume of fluid (VOF) technique is used to study the non-linear behavior and damping characteristics of liquid sloshing in partially filled rectangular tanks subjected to large amplitude excitation. The excitation is assumed to be harmonic to simulate tank motion. The fluid is assumed to be homogeneous, isotropic, viscous, and Newtonian and exhibits only limited compressibility. Tank and fluid motions are assumed to be two-dimensional. A moving coordinate system is used to include the non-linearity and avoid the complex boundary conditions of moving walls. The numerical model solves the complete Navier-Stokes equations in primitive variables by using of the finite difference approximations. The VOF technique is used to track the free surface and, at each time step, a donar-acceptor method is used to transport the volume of fluid function and hence the locations of the free surface. The numerical method also allows the interaction of the fluid with the tank top. In order to assess the accuracy of the method used, computations are compared with the experimental results. Comparisons show good agreement for both impact and non- impact type slosh loads in the cases investigated.

Keywords: Sloshing, Hydrodynamic loads, Free surface flow, Volume of fluid technique method

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