ON THE ANALYSIS OF SLOSHING OF WATER IN RECTANGULAR CONTAINERS - NUMERICAL STUDY AND EXPERIMENTAL VALIDATION

In this work the analysis of sloshing of water in rectangular open tan ks has been extensively carried out. Two mathematical models are emplo yed, respectively the Reynolds Averaged Navier Stokes Equations (RANSE ) and the Shallow Water Equations (SWE). The RANSE are solved using a modified form of the well established MAC method (SIMAC) able to treat both the free surface motion and the viscous stresses over the rigid walls accurately. The Shallow Water Equations are solved by means of a simple and powerful algorithm (CE-SE) able to deal with large impacti ng waves over the tank walls. Successively, in order to validate the m entioned algorithms and for a better understanding of the sloshing phe nomenon, experimental tests have been carried out using a 0.5 m breadt h rectangular tank in periodic roll motion. It has been shown that RAN SE provide more accurate solutions than SWE for small or moderate ampl itudes of excitation. In particular in this paper it is proved that th e shallow water approximation can be efficiently adopted within liquid depth to tank breadth ratio = 0.15, when examining the sloshing probl em. By increasing the water level inside the tank, results by SWE show large qualitative and quantitative disagreement with experiments. Nev ertheless, in the case of large amplitude excitation, when sprays and large breaking waves are expected, SWE provide a fairly good estimate of the sloshing induced waves. Finally a simple baffle configuration i nside the tank has been considered. By the analysis of numerical resul ts, it has been observed that the presence of a vertical baffle at the middle of the tank dramatically changes the sloshing response compare d to the unbaffled configuration. It produces a jump-like effect, resu lting in a weak magnification of the dynamic loads on the vertical wal ls out of resonance, and a strong reduction of the dynamic loads in th e resonance condition. Copyright (C) 1996 Elsevier Science Ltd