## 5 Results and Discussion
### The Results of the Verification Study  
The verification study was conducted for the ship model at a Froude number calculated based on the water depth equal to \(Fn_{h}=0.469\), which corresponds to the ratio of the water depth to the ship draft of 1.78. The results of the verification study are presented in  
Based on the obtained verification results, it is evident that the total numerical uncertainty for the total resistance is very small for both analyzed turbulence models. In contrast, the total numerical uncertainties for trim and sinkage obtained using the RKE turbulence model are significantly higher.  
Table 7 provides the values of the relative deviations for the total resistance, sinkage, and trim of the ship model calculated according to Equation (9) for the RKE turbulence model, while Table 8 shows the relative deviations of the results obtained using the SSTKO turbulence model. It can be seen that the relative deviation for the total resistance obtained using the RKE turbulence model is significantly lower in comparison to the one obtained using SSTKO. The relative deviations for the sinkage and trim are quite pronounced for both turbulence models ranging from \(8.5\%\) to \(10.55\%\). However, it should be noted that the experimental uncertainties for both trim and sinkage are higher than \(90\%\) at low speeds [15]  
\(-3.05\%\). Conversely, for a trim by stern, the total resistance increases, even by 4.51% for a trim of \(-0.4^{\circ}\) in comparison to an even keel.  
Based on the obtained relative deviations, it is evident that the pressure resistance changes the most with trim variation. For a trim by bow, there is a reduction in pressure resistance compared to an even keel, which contributed to an overall decrease in the total resistance of the ship model at those trims. Conversely, for a trim by stern, there is a significant increase in pressure resistance, ultimately resulting in higher total resistance. Regarding frictional resistance, it decreases at trims by bow and increases for trims by stern. The wetted surface area for trims by bow are smaller in comparison to the one at an even keel. For trim by stern, the wetted surface area is 1.04% and 0.62% lower for trims of \(-0.4^{\circ}\) and \(-0.2^{\circ}\), respectively, in comparison to an even keel. The reduction in the wetted surface area for the trim by bow amounts to \(-0.84\%\) and \(-1.61\%\) for trims of \(0.2^{\circ}\) and \(0.4^{\circ}\), respectively, in comparison to an even keel. In general, the effect of trim on the frictional resistance is much smaller in comparison to pressure resistance. It can be concluded that the trim has a significant impact on altering the pressure resistance, while its effect on frictional resistance is also present but to a lesser extent  
the contrary, the part of the wave resistance obtained by the SSTKO turbulence model is larger in comparison to the one obtained by the RKE for all analyzed trims. For example, the part of the wave resistance in the total resistance for a trim of 0.4\({}^{\circ}\) obtained by RKE and SSTKO is equal to 3.32% and 9.36%, respectively. The effect of trim on the form factor is almost negligible, while the form factor calculated based on the results obtained using the SSTKO turbulence model is approximately 3% larger than the one calculated using RKE.