## 2 Literature Review  
Inevitably, liquid sloshing occurs in partially filled tanks subjected to external excitation. Therefore, effective engineering design of a sloshing-mitigation device is crucial for various applications of water tanks. A variety of mitigation devices, such as baffles and floating foam layers, have been introduced, with baffles regarded as the most effective. The mitigation performance of baffles in water tanks has been investigated by experimental and numerical simulation methods. From the early days of this field, researchers have conducted various sloshing experiments, both with and without baffles, and, in the past 20 years, several important studies have been published on the anti-sloshing effectiveness of baffles. [PERSON] and [PERSON] [3] examined the non-linear behaviour and damping characteristics of sloshing in a partially filled three-dimensional (3D) rectangular tank. Specifically, they examined pressure distributions at different locations and the 3D effects of sloshing with and without baffles, respectively. They found that a side horizontal baffle mimicked shallow-water effects in a deep-water scenario, and thus could enhance the travelling characteristics of a sloshing wave. Their conclusion was that baffles significantly reduce fluid motion. [PERSON] et al. [4] performed a series of experiments to estimate the pressure on a rectangular tank wall and the free surface displacement under various excitation frequencies, various filling levels, and with and without baffles. They determined that the presence of baffles in the tank decreased the sloshing effect, as the sharp-edged baffles created turbulence in the flow field, such that excess kinetic energy was dissipated onto the tank's walls. [PERSON] et al. [5] investigated the efficiency and characteristics of a rectangular tank system equipped with a horizontal perforated plate under various excitation amplitudes and frequencies. They obtained the best results with a plate that had a perforated area less than or equal to the total surface area between the tank compartments and that was placed beneath the water surface. [PERSON] et al. [6] studied sloshing in a tank \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{2}{c}{**Structure**} & \multirow{2}{*}{**Fluid**} & \multicolumn{2}{c}{**Anti-Wave Plate**} \\ \cline{2-5}  & **Static** & & & **No Plate** & **50\%H** & **70\%H** \\ \hline CASE & & & & & \\ I-1,2,3 & & & & & \\ CASE II & & & & & \\ CASE III-1 & & & & & \\ CASE III-2 & & & & & \\ CASE III-3 & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cases of numerical simulations. ( means the applied conditions in the present study). with one of four types of vertical baffle, namely perforated, flushing with a free surface, surface-piercing bottom-mounted, and immersed bottom-mounted vertical baffles. They identified the sloshing pressure distribution on the baffles and the tank wall, and identified the sloshing-damping effects of the baffles when the tank was subjected to various frequencies of forced horizontal excitation. They concluded that the ability of the vertical baffles to decrease sloshing pressure depended on the relationship between the forcing and natural frequencies and the baffles' configuration and location. [PERSON] et al. [7] invented a moving baffle that contained a spring system and examined its effectiveness in a series of sloshing experiments in a rectangular tank under swaying motion. They found that the ability of spring-connected horizontal baffles with high spring stiffness to reduce sloshing was similar to that of fixed baffles. [PERSON] et al. [8] examined the effect of vertical baffles on parametric sloshing and observed that as the distance between the baffles and the nodes of sloshing modes decreased, the damping effectiveness of the baffles increased.