The paper raises the question of the possibility of reducing the energy loss of the stage of the centrifugal pump on the disk friction, the relative value of which for the stages of low and ultralow speed can be a significant proportion (up to 40%) of all losses. This is seen as one of the effective ways to increase the efficiency of such stages of centrifugal pumps.

The article is devoted to the research of the torque-flow pump operating process. Its work is closely connected to the formation and stable functioning of the toroidal vortex. The theoretical bases of the formation of a toroidal vortex and the process of energy transfer in a torque-flow pump are considered in the research (vane and vortex components of the operating process). The fact of the presence of some additional hydraulic losses due to the mismatch of the location of the toroidal vortex center and the impeller blade edges has been established. The urgency of the paper is increasing the efficiency of torque-flow pump by improving its flowing part. The upgrade of the pump consists of the theoretical justification and practical implementation of the reduction of these additional hydraulic losses. In this aspect, the location of the impeller blade edge is aligned with the toroidal vortex center. The research was performed by conducting a numerical investigation. The calculations of a high specific speed torque-flow pump of three different design configurations of the impeller blades were performed. Practically confirmed increasing of the head (by 3.2 m) and efficiency (by 7-8%) of the pump with the second design of the impeller blades.

Purpose. Evaluation of the effect of changing the width of the impeller blades on the characteristics of a torque-flow pump. Searching for the optimal blade extension into the free chamber of the pump. A torque-flow pump of the “Turo” type SVN 500/32 was chosen as the subject of the research work. Methodology. A number of numerical experiments were conducted to determine the flow structure in the flowing part of a torque-flow pump. The width of the impeller blade was chosen as a variable. Numerical experiments were carried out using the ANSYS CFX software package. The integral parameters of the researched pump were determined in order to build the integral characteristics. Findings. The structure of the general flow and toroidal vortex was studied and analyzed in the torque-flow pump. A flow model was built in a torque-flow pumps with basic and modernized design. A relationship between the parameters of the pump and the change in the impeller blade width was found. The width of the impeller blade was changed in the range from min = -20 to max = +100 mm. Originality. The paper researched the effect of additional hydraulic losses caused by the mismatch between the center of the toroidal vortex and the edges of the impeller blades on the integral characteristics of the torque-flow pump. Practical value. A significant increase in the operating parameters of the “Turo” type torque-flow pump was achieved with the help of modernization of the impeller design. This allows expanding the range of the pump’s operation. At the same time, it is not required to replace such expensive elements as the pump casing.