UkrainianProfessional Education

Abstract

An important component for the capacity of irrigation canals is the determination of water flow parameters. Therefore, the purpose of the study was to consider the conditions of water flow under which unsteady motion occurs in the cross-sections of irrigation canals and hydraulic structures. Analyzing these conditions will make it possible to correctly determine the capacity of such structures, which is extremely important for their design and efficient operation. The main problem is the lack of appropriate recommendations for taking into account unsteady traffic when calculating the capacity of structures on irrigation canals. While such recommendations exist for steadystate traffic. Thus, one of the objectives of the study is to determine the effect of boundary conditions on the characteristics of movement in cross sections of structures during unsteady flow. The results obtained will be important for determining the capacity of hydraulic structures under different flow regimes, which is key to their optimal operation. When reconstructing irrigation canals, one of the ways to increase their capacity is to increase their geometric dimensions. However, if the dimensions of the structure are left unchanged, it will restrict the channel after it is widened, causing a backwater near the structure. When deciding on the reconstruction of an irrigation canal, it is important to consider how different degrees of compression of the canal by the structure will affect the flow elements under conditions of unsteady flow. Studying this issue will help determine the ability of the existing structure without reconstruction to ensure the passage of increased water flows at acceptable levels after the canal expansion. A number of numerical experiments have been conducted that take into account the impact of various indicators on the capacity of the structure. The analysis of the actual conditions of flow in irrigation canals made it possible to properly take into account the nature of unsteady flow in the operation of the irrigation system as a whole. Consideration of the change in water flow in the barrier structure will allow us to determine how flow fluctuations decrease with distance from the structure. This phenomenon is known as flattening or transformation, and it is important in the design of hydraulic structures in irrigation systems

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