In addition to consuming, using, and benefiting from it, it has sometimes become necessary to establish defense mechanisms against water. In particular, precautions against floods, torrents, and sediment transport in the flow have been essential. Since they damage settlement areas, disrupt aquatic life, and affect productive lands, various water structures have been built to address these issues. Among these structures are spur dikes specifically constructed for this purpose. In this study, a new spur dike structure was designed by taking inspiration from the Eğri Bridge located within the borders of Sivas province. Various experiments were carried out by arranging the spur dikes made of quality waste material on both sides of the open channel in an asymmetrical arrangement. CFD technology was used to see the effect of this designed structure on the flow hydraulics and characteristics more clearly. For this purpose, Standard k-ε, RSM, and LES models were compared with different data groups. Two configuration models of the same geometry were used in this study. AS-1 and AS-2 represent arrangement models numbered 1 and 2, respectively. Model verification of numerical data was performed for all flow rates of the AS-1 and AS-2 configurations. Firstly, water surface profiles were compared using experimental flow depths. Then, energy dissipation values ​​were compared using flow rates and depth values. Additionally, separations in the streamlines occurring in the spur dike area and division eyes, along with secondary flows, turbulence, and vortex formations, were simulated. While the experimentally dissipated energy approached a maximum of 65%, it remained around 50% in the RSM and LES models. The RSM and LES models effectively captured the vortices and eddies between the spur dikes. While the vorticity magnitude reached a maximum of 200 1/s for Case AS-1, 300 1/s values were obtained for Case AS-2. This phenomenon had a direct impact on the amount of energy dissipation. The power to capture the vorticity magnitude values in total can be listed as Standard k-ε < RSM < LES. Additionally, better water surface profiles were obtained from both models when compared to the Standard k-ε turbulence model. For high flow rates (for Q = 9.33 and Q = 11.12 l/s), the VOF-RSM and VOF-LES models captured the cases where the mesh cell was over 75% full of water. However, we can say that the VOF-LES model is more economical because the solution time is shorter. The results blend the effects of past field applications with future technology on a new design.

The increase in population causes the need for water to increase day by day. The fact that water resources are limited further emphasizes the effective use of water. For this purpose, level-flow control of water transmitted through open channels is very important. Broad-crested weir types are widely used in these controls carried out through weirs. In this study, a newly designed broad-crested weir type that has not been used before was used. The model created in the laboratory environment was tested for two different flows. Flow depths and velocity values were measured. To test the study's accuracy, three-dimensional solutions were performed with Ansys-Fluent software. It was observed that there was general agreement between experimental and numerical data. It was seen that this study allowed different designs to be tested at less cost before moving on to field applications. In addition, it has been understood that the weir structures applied in the field can be detected through computer software to determine the sections where they may be damaged.

The flow accumulated behind a water body or released from a high level has a very high amount of hydraulic energy. Since this energy causes high speeds in the flow, it creates high pressure and friction conditions. As a result, it creates scour, erosion and cavitation problems on the water structure or downstream. This is an undesirable situation. If precautions are not taken, it causes the water structure to collapse completely or the facilities and structures around it to suffer serious damage. In field applications, energy-breaking structures are constructed to bypass such negative situations. Chute channels, drop beds or energy-breaking basins are the most preferred of these structures. Blocks placed especially on chute channels or inside energy-breaking basins are quite effective in absorbing the energy of the flow. These blocks absorb the energy of the flow by creating turbulence inside them. Sometimes this turbulence situation is achieved by the flow hitting the blocks and sometimes by separating the flow. The aim here is to reduce the supercritical velocities to subcritical. This can only be achieved by providing a hydraulic jump. In this study, energy breaking situations of single-row and double-row block arrangements were investigated in a numerical environment. For this, 3D solutions were obtained using Ansys-Fluent software. A T-shaped block geometry was selected as the block shape. Such a block type was preferred to increase the surface parts of the current hitting the blocks and thus to observe the energy absorption situation. According to the results of the study, the single-row block type provided more energy absorption. It can be said that this study will be an important base in determining the current and block interactions that cannot be measured experimentally before moving on to field applications.

In recent years, computational fluid dynamics software has significantly contributed to the literature on flow characteristics and turbulent solutions in open channel flows. In this study, two vegetation patch arrangements underwent numerical simulation using the Reynolds Stress Model in Ansys-Fluent software. The flow dynamics of the two cases were compared, and the responses of vegetation patches under subcritical flow conditions were investigated. First, the model was validated and then utilized for numerical simulation. It was observed that more effective velocity reduction occurred in the vegetation patch region and immediately downstream of the patches. While the vegetation patch in Case-1 reduced the flow velocity by 57% compared to the flow velocity at the channel entrance, it remained at 52% for Case-2. The depth-averaged vertical velocity distribution at points P1 and P2 showed lower values downstream for Case-2. Regarding the effect in the downstream region, the turbulence area in Case-2 was narrower compared to Case-1, with turbulent kinetic energy values greater than 0 observed in the channel center. While the energy dissipation percentage was 30% for Case-1, approximately 43% was achieved in Case-2. These results strongly support the feasibility reports with visuals and big data opportunities of CFD sampling before field applications.