ОПТИМІЗАЦІЯ РОБОЧОГО КОЛЕСА ВІДЦЕНТРОВОГО НАСОСА ДЛЯ ОБОРОТНИХ ГІДРОМАШИН МЕТОДОМ ЧИСЛОВОГО МОДЕЛЮВАННЯ

The article discusses the process of designing and optimizing the impeller of a centrifugal pump, which is an intermediate stage in the design of a reversible hydraulic machine for a pumped storage power plant. The need to improve the energy efficiency and reliability of hydraulic units operating in pump mode at high pressures is a pressing issue. The research methodology is based on the comprehensive use of Ansys software: Vista CPD for preliminary design, BladeGen for blade generation, TurboGrid for mesh generation, and CFX for numerical calculation of three-dimensional flow. At the first stage, the basic geometry of the impeller was obtained and a CFD analysis was performed, which revealed characteristic problems: an increase in meridional velocity to 30 m/s in the narrowed zone of the channel and a sharp pressure drop at the rear edge of the blade. This led to an increase in hydraulic losses and an increased risk of cavitation. At the second stage, the flow part in the meridional plane was modified by locally expanding the channel, which reduced the unevenness of the velocity distribution. At the third stage, the blade profile was optimized by reducing the thickness at the trailing edge and correcting the flow entry angle. A comparison of the flow patterns and integral performance indicators of the three options showed that modification 2 provided the best results: more uniform velocity distribution, more stable pressure along the blade, and a reduction in vortex structures and local accelerations. According to calculations, the outlet pressure increased from 4.23 to 4.35 MPa, the total head from 588 to 621 m, and the efficiency from 0.927 to 0.952. Thus, the heuristic approach used allows for a significant increase in the energy efficiency of the impeller and can be used to optimize the reversible hydraulic machines of high-pressure pumped storage power plants.