Numerical simulation of sloshing in a rectangular tank subjected to rotational motion

Sloshing waves induced by the rotational motion of the tank have been simulated using the mixed Euler-Lagrangian formulation. The fully nonlinear wave model is solved using the finite element method with the cubic spline and finite difference approximations of velocity recovery to minimize the need for smoothing and re-gridding. In the present model, the rotational motion is built into the kinematic and dynamic boundary condition and the problem is solved in the fixed coordinate system without moving the tank. The results are compared with Nakayama et al.(1980) in the time domain and with experimental measurements of Nasar et al.(2008) in the frequency domain. A good agreement with results is achieved and also, it is shown that the present model predicts the different sloshing harmonics well. Further, harmonics present in a tank with 25% fill liquid level, is explored for two roll amplitudes(10 and 20) for a range of frequencies. Similar harmonics are observed for both the roll amplitudes. The variation of sloshing response is highly sensitive near the sloshing frequencies and is less sensitive at off-resonance frequencies. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).