## 3 Model Simulation Setup  
To determine the dimensions of the floating object, a market survey was conducted, analyzing 40 different barges (floating object) to extract ratios of length/depth, width/depth, and length/width. Based on the obtained ratios, two different floating objects with lengths of 15 m, widths of 6 m, and depths of 2 m were selected--one with a blunt bow and the other with a raked bow. The dimensions of the floating object were varied in relevant scenarios. Figure 1 illustrates the floating object with a blunt bow, while Figure 2 shows the floating object with a raked bow. The dimensions of the computational domain were chosen to encompass the time interval necessary to observe the hydrodynamic and morphodynamic features examined in this study. Additionally, the study area for the parameters of interest needed to be sufficiently distant from the domain boundaries to avoid potential influences from boundary conditions. The maximum towing speed of the floating object was considered as 2 m/s in this study. The object accelerates to this speed in 25 s and continues to be towed at this speed for an additional 25 s. Considering the total distance covered by the floating object, the length of the computational domain was set to 100 m.  
Figure 1: Isometric view of Floating Object 1 with a blunt bow. To determine the width of the computational domain, various numerical models were created to examine the effects of domain width on the hydrodynamic and morphodynamic results. Based on these analyses, the domain width was set to 28 m to ensure that the movements of the floating object and the resulting morphological changes on the seabed were not affected by the boundaries. The determination of grid size is crucial to accurately represent the physics of interest while maintaining computational efficiency. A sensitivity analysis was performed to optimize the grid size and structure. The analysis began with an initial grid configuration suitable for the physics to be examined, followed by systematic reductions in grid size. Hydrodynamic results, morphological changes, and computational times were compared at each step. The process continued until further reductions in grid size resulted in negligible differences in the results, indicating an optimal point where increased computational effort did not yield significant benefits. A sensitivity analysis was performed to determine the optimal size and structure, examining various grid configurations and dimensions. Starting with a total grid element count of 1,294,362 and reaching up to 10,092,000, a total of 11 different models were compared in terms of hydrodynamics, morphodynamics, and computational time. Based on these studies, a grid configuration was selected where the grid size was uniform throughout the domain but refined near the seabed to 0.0375 m. This resulted in a grid size of 0.0375 m near the seabed and up to 0.15 m near the water surface, totaling 3,597,798 grid elements in the computational domain. The grid configuration used in the numerical model studies is detailed in Figure 3.  
The computational domain was configured with carefully selected boundary conditions to accurately represent the physical system under investigation. Given that the study focuses solely on the effects of the floating object and sediment interactions, with  
Figure 3: Grid structure used in the numerical model: (**a**) Isometric view, (**b**) side view, (**c**) front view, and (**d**) side view of the refined grid structure near the seabed. Figure 2: Isometric view of Floating Object 2 with a raked bow. no external forces other than atmospheric pressure considered, the following boundary conditions were implemented. 1. Minimum Z-axis Boundary: A \"wall\" boundary condition was imposed to represent the solid bottom of the domain. 2. Maximum Z-axis Boundary: An \"atmospheric pressure\" condition was applied to simulate the open air interface at the top of the domain. 3.