## 3 Results and Discussion
Two peak points were formed in the sloshing movement in the empty tank, and an impact effect occurred at the P5 measurement point. The behavior at points P1, P2, P3, and P4 was also similar. It was determined that the free surface movement of the fluid did not reach point P5, and there was no pressure change in the baffled structures. The pressure changes at other measurement points were reduced, and the baffled structures  
Figure 5: Contours of velocity magnitude of the unbaffled tank for different simulation times. dampened the sloshing motion. So, the type of baffle structure affected the effectiveness of the pressure change during sloshing. It was observed that the pressure fluctuation magnitudes of the one flat baffled-walled and multi-baffled tanks gave better results than the circular perforated baffle tank structure. The behavior of the liquid became more stable, and liquid inertial forces could not propel the liquid more to reach the ceiling of the tank. Figure 6: The pressure history curves of sloshing for points P1, P2, P3, P4 and P5 for different baffle structures (\(A=0.1\) m, \(\omega=5.02\) rad/s). The effect of the filling rate on the sloshing behavior was investigated for the same tank structures by setting a liquid fill rate of 70%. The excitation amplitude was the same as 0.02 m, and the operating frequency was calculated by Equation (6). When the system's dynamic behavior was examined, it was seen that the pressure values at the measurement points (P1-P4) increased, and an impulsive effect occurred at point P5 with the increase in the filling depth, as shown in Figure 8. However, it was observed that the pressure fluctuation decreased with the increase. It was observed that the pressure change occurred close to the impulsive effect, especially in the tank with a circular perforated baffle structure, where the fluid reached point P5 in baffle tank structures. It was determined that the multi-baffled tank structure dampened the sloshing behavior better than other structures. When the pressure change graphs of the unbaffled tank structure from Figures 7 and 8 were examined, it was observed that the pressure fluctuations in the tank with a 70% fill rate were minor. The analysis results obtained by filling the tanks with water and kerosene fluids are shown in Figure 9. The specifications of these fluids are summarized in Table 3. \begin{table}
\begin{tabular}{c c c c c} \hline  & \(\rho\) (kg/m\({}^{3}\)) & \(\mu\) (kg/(m\(\cdot\)s)) & \(c_{p}\) (J/kgK) & \(k\) (W/(mK)) \\ \hline Water & 998.2 & 0.001 & 4182 & 0.6 \\ \hline Kerosene & 780 & 0.0024 & 2090 & 0.149 \\ \end{tabular}
\end{table} 
Table 3: Fluid specifications. Figure 7: The pressure history curves of sloshing for points P1, P2, P3, P4 and P5 for 50% filling rate (\(A\) = 0.02 m, \(\omega\) = \(\omega_{n}\)). Figure 8: The pressure history curves of sloshing for points P1, P2, P3, P4 and P5 for 70% filling rate (\(A=0.02\) m, \(\omega=\omega_{n}\)). Figure 9: The pressure history curves of sloshing for points P1, P2, P3, P4 and P5 for water and kerosene liquids (\(A=0.02\) m, \(\omega=\omega_{n}\)). Here, two different analyses were performed for the unbaffled tank with the 50-70% filling rate, and the circular perforated baffled tank structure for the baffle-structured tank was examined with a 50% filling rate. As seen from the analysis results, pressure variation in the tank also changed due to the differences in the properties of the fluids, such as density and viscosity. In both fluid structures, the difference between the minimum and maximum values for the pressure fluctuation decreased with the increase in the liquid level in the tank, hence the fluid mass.