ДОСЛІДЖЕННЯ ГІДРОДИНАМІЧНИХ ХАРАКТЕРИСТИК РОБОЧОГО КОЛІСА ОБОРОТНОЇ ГІДРОМАШИНИ

The current problem of development and restoration of pumped storage power plants in Ukraine is considered, in particular in the war conditions, which significantly damaged the energy infrastructure and created a capacity shortage. Pumped storage power plants play an important role in the power system stabilization, as they accumulate energy during low load and promptly use it during peak periods or in case of accidents. At the same time, they contribute to increasing the energy autonomy of the country and the integration of renewable energy sources. It is noted that when modifying the runner of such hydraulic machines, there is a need to change the geometry of individual lattice. The quantitative assessment of thechanges made should be based on the kinematic and energy analysis of each runner lattices. Analysis of the energy and kinematic characteristics of the spatial runner lattice allows to determine the contribution of each separate lattice (periphery or hub) to ensuring the necessary operational characteristics. The use of dimensionless parameters to determine the hydrodynamic characteristics of elementary runner lattices allows to identify the regularities of the working process and to assess the influence of the runner geometry and the regime parameters of the hydraulic machines on the energy characteristics. It was found that the optimal mode is achieved at approximately the same value of positive circulation for all lattices; that build the spatial runner lattice. Numerical modeling of the spatial flow of viscous fluid in the runner of reversible hydraulic machines was performed in this work. The results of the research allowed to analyze the velocity distribution in the runner. The steady nature of the flow along the output edge of the runner was confirmed. This result indicates the consistency of the elementary lattices in the optimal operating mode, which provides high energy indicators of the hydraulic machine. A comparative analysis of the results obtained by different models with the results of the physical experiment showed satisfactory convergence. Obtained results indicate the expediency of using the selected methods for studying reversible hydraulic machines.