Shudryk O. Increasing of efficiency of the use of centrifugal pumps by perfection of mathematical models of working process

The object of the study is the hydrodynamic processes in the flow section of the submersible multistage centrifugal pump. Subject of research - characteristics of a submersible centrifugal pump, which take into account both the structure of the flow, the viscosity and the availability of free gas, by improving the mathematical model of the work process. The purpose and tasks of the study. The purpose of the study is to increase the efficiency of submersible centrifugal pumps by improving the mathematical models of the work process. To achieve this goal, the following tasks are set: 1. To analyze and generalize the current state of the modeling of the working process in the blade hydraulic machines, experimental research of the operation of submersible centrifugal pumps for real operating conditions. 2. To develop a three-dimensional mathematical model of the working process of the degree of a centrifugal pump on the basis of taking into account the peculiarities of the flow of the gas-liquid mixture in the flow section. 3. Conduct numerical studies of the working process of the Newtonian, Non-Newtonian fluid and gas-liquid mixture in the degree of a submersible centrifugal pump. Research methods. In the course of the dissertation work, the fundamental positions of the theory of fluid mechanics and gases were used. The tasks put in the work are solved on the basis of methods of computational hydrodynamics and experimental research. Mathematical modeling of hydrodynamic processes in flow parts of submersible centrifugal pumps was carried out using the methods of computational fluid dynamics, which were implemented in the OpenFOAM software complex. The scientific novelty is as follows: - the mathematical model of the three-dimensional flow of a non-Newtonian fluid of the Herschel-Bulkley type for a water-oil emulsion and a gas-liquid mixture in the degree of a centrifugal pump was developed for the first time, which allows taking into account the peculiarities of the design of the small-scale pump stage, the composition and properties of the pumped medium; - functional dependences have been improved to determine the effective fluid viscosity, conversion factors, and the efficiency of submersible pumps, which improves the accuracy of prediction of performance on the actual pump operating conditions;