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14 H.AKYILDIZ

vertical baffle are most pronounced in shallow water and consequently the pressure response is
reduced by using the baffles. When an internal element is put into a tank, the liquid viscosity
cannot be neglected and energy is dissipated by viscous action. Celebi and Akyildiz (2002)
revealed that flow over a vertical baffle produces a shear layer and energy is dissipated by
viscous action. They concluded that, in an increased fill depth; the rolling amplitude and
frequency of the tank with or without baffle configurations directly affect the degrees of non-
linearity of the sloshing phenomena. As a result of this, a phase shift in forces and moments
occurred.

Kim (2001) analysed the sloshing flows with impact load in the two and three-dimensional
containers based on a finite difference method. In this study, the Navier-Stokes equation with
free boundary was solved using the SOLA scheme and the free surface profile was assumed to
be a single-valued function. Armenio and La Rocca (1996) adopted the finite difference method
to solve the 2D RANS equations to overcome the strong interaction between vorticity and free
surface motion. The control of the sloshing behaviour with baffles is also a subject of interest in
the recent years, because of the complexity and highly non-linear nature of the problem. Some
researches carried out the experimental and numerical studies and pointed out the above
mentioned characteristics (Akyildiz and Unal, 2006; Panigrahy et al., 2009; Pal et al., 2002;
Sames et al., 2002).

Cho and Lee (2004) denoted that the liquid motion and the dynamic pressure distribution above
the baffle are more active than those below the baffle by carrying out the parametric study on
two-dimensional liquid sloshing. They used the baffled tank under forced horizontal excitation
considering potential flow theory. Cho et al. (2005) carried out a numerical method to analyze
the resonance characteristics of liquid sloshing in a 2D baffled tank. They cannot resolve the
viscous and the rotational motion of the liquid sloshing because of the potential flow theory.
Pal and Bhattacharyya (2010) carried out the numerical and experimental studies of liquid
sloshing for 2-D problem. The resulting slosh heights for various excitation frequencies and
amplitudes are compared with the data obtained numerically. It was concluded that the little
variations in the data are due to the ineptness of the experimental set up and the input
parameters. Younes et al. (2007) investigated the hydrodynamic damping experimentally in
rectangular tanks with vertical baffles of different heights and numbers. It is pointed out that the
damping ratio increases by increasing the baffle numbers.

Liu and Lin (2009) studies 3D liquid sloshing in a tank with baffles using the numerical
approach. They showed that the vertical baffle is more effective than the horizontal baffle in
reducing the amplitude and the pressure on the wall. The commercial CFD code has been
utilized to investigate the liquid sloshing recently (Godderidge et al., 2006b, 2007; Godderidge
et al., 2009a, 2009b). They showed good agreement with the experimental data.

In this study, the effects of the vertical baffle height and the horizontal baffles on liquid sloshing
in a rolling rectangular tank have been investigated. Furthermore, it is examined that how the
vortex resulting from the baffle tip affects the liquid sloshing and flow physics. A numerical
algorithm based on the volume of fluid technique (VOF) is used to study the non-linear
behaviour of liquid sloshing. The numerical model solves the complete Navier-Stokes
equations in primitive variables by using of finite difference approximations with the moving
coordinate system. It is difficult to analyse how flow physics such as the vortex from the baffle
tip could be used to understand the effect of the baffle on liquid sloshing. Therefore, the main
purpose of this study is to examine the behaviour of the tip vortex and to assess numerically

GiDB|DERGi Sayı 1, 2014