Experimental and numerical analysis of spur dikes placed differently in plan in open channel flows

Spur dikes, which have an important place in the regulation of free-surface flows, are hydraulic structures that have the potential to greatly affect flow characteristics. The application and construction of spur dikes do not adhere to a single standard, and since their designs are site-specific, they can be found in multiple types, designs, shapes, numbers and sizes in different areas. Spur dikes, whose properties vary according to their intended use, are generally and widely used to eliminate sediment accumulation and coastal erosion. In this thesis study, the energy dissipation potentials of spur dikes placed in groups in an open channel with different heights, lengths, spacing, and placement angles, as they have not been used in this sense before, and their hydrodynamic effects on the flow were investigated. For this purpose, physical model studies carried out in the laboratory were carried out together with numerical model (CFD: Computational Fluid Dynamics) studies under similar boundary conditions. In this context, a total of 549 model studies were carried out under different geometry and flow conditions of the spur dikes placed differently in the plan. From CFD analyses, flow characteristics such as streamlines, flow velocities and turbulence intensity in the flow, which could not be obtained from the experimental set, were obtained and interpreted. The findings obtained from the thesis have shown that the submergence and ratio of spurs designed in groups and placed in an open channel have significant effects on flow properties such as energy dissipation and turbulence. Moreover, the ratio of the spur lengths to the channel width was also found to have a significant effect on the energy dissipation potential in the flow. It is understood from CFD analyses that the aspect ratios of the models cause significant differences in the upstream water level and the formation of turbulence and eddies in the flow field. In line with the results obtained from the study, it was determined that the designed models can serve multiple purposes, such as energy dissipation in streams, reducing flood risks, protecting of river habitat and benefiting aquatic organisms. The study is thought to contribute to the related literature on the basis of river regulation.