Purpose. Search for the possibility of increasing the efficiency of dredge pumps for viscous fluids by determining the rational values of the blade-outlet inclination angles in the pump impellers. Methods. During the research, the following is used: theoretical studies of the structure of the viscous fluids flowing through the flow part of dredge pumps; the method of three-dimensional software-simulation modeling of hydrodynamic processes using the Ansys software package; the methods of rational experiment planning for selecting the values of the number of points in the computational grid when optimizing the geometric parameters of the dredge pump impellers; methods of mathematical statistics and correlation analysis. Findings. It has been proven that the main reason for the failure of the flow part components in the dredge pumps is the manifestation of the influence of cavitation processes, which can be eliminated by changing the blade-outlet inclination angles in the pump impellers. A software-simulation complex for the automated design of the flow parts in the dredge pumps has been developed based on the use of optimization algorithms and computational fluid dynamics methods, which makes it possible to design dredge pumps with optimal characteristics that ensure their efficient operation with maximum efficiency values. It has been determined that one of the main factors influencing the head developed by dredge pumps and the efficiency value is the blade-outlet inclination angle in the pump impellers. Originality. Scientific novelty is in the scientific substantiation and development of a simulation-mathematical method for calculating the geometric parameters of the flow part in dredge pumps for viscous fluids at the design stage. Practical implications. The developed method for determining the rational blade-outlet inclination angles of the impellers in the dredge pumps for viscous fluids can be recommended to scientific-research and industrial organizations for use in the improvement, design and operation of the dredge pumps.

The work objective is to prove the possibility of expanding the scope of using hydraulic drive in machines and mechanisms of small and medium power. The problem to which the paper is devoted. Reduction of weight and size parameters of hydraulic machines. Research methods. The problems were solved on the basis of the electrohydraulic analogy method. The novelty of the work. It consists in finding the possibility of replacing complex, large-sized and massive distributors with the simplest hydraulic elements - valves (distributors 2/2) Study results. The conducted studies confirm the possibility to simplify hydraulic circuits significantly, to reduce weight and size parameters and increase the reliability of hydraulic machines. Conclusions. Taking into account the general principles of electric and hydraulic drives operation and using the method of electrohydraulic analogy, it is advisable to make hydraulic drive control systems by analogy with electric drives, based on the simplest elements of the valve type (hydraulic distributor 2/2).

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