DEM parameters calibration is the most important step in preparing a DEM model. At the same time, the lack of a universal approach to DEM parameters calibration complicates this process. The paper presents the author’s approach to creating a universal calibration approach based on the physical meaning of the friction coefficients and conducting symmetrical experiments at full scale and in a simulation, as well as the implementation of the approach in the form of a physical test rig. Several experiments were carried out to determine the DEM parameters of six material–boundary pairs. The resulting parameters were adjusted using a refinement experiment. The results confirmed the adequacy of the developed approach, as well as its applicability in various conditions. The limitations of both the approach itself and its specific implementation in the form of a test rig were identified.

This paper studies the effects of pipeline inner surface materials on hydrotransport energy parameters in the transportation of tailings slurry. It has been established that pipelines with inner surfaces made of polymeric materials ensure higher transportation energy efficiency due to lower specific pressure losses. The respective laboratory tests were carried out in two stages. At the first stage, pressure losses in the transportation of pure water and the initial roughness of the pipe samples studied were experimentally established. At the second stage, changes in sample roughness were studied in the hydrotransport of tailings slurry. The samples were represented by pipes made of high-density polyethylene with an inner layer of thermoplastic vulcanizate; single-layer pressure pipes manufactured in compliance with GOST 18599; and previously used longitudinally electric-welded steel pipes under GOST 10704-91. The influence of the hydraulic friction coefficient on the specific pressure loss and energy intensity of the hydrotransport process has been analyzed. Equivalent roughness values have been established for pipelines made of polymer materials and steel. The relationship between the roughness height parameters of Ra, Rq, Rz and the equivalent even-grained roughness has been established; their changes during tailings slurry hydrotransport ha

The article discusses the structure of autonomous electrical systems with an electric drive and an electric energy generation system. An approach is described for assessing the overall efficiency of technological cycle equipment with specification of parameters that must be considered when calculating it. The necessity of taking into account energy efficiency and operability indicators of autonomous electric complexes is substantiated. The effectiveness of the use of autonomous systems decreases throughout the entire life cycle due to wear and tear. As the operability of electromechanical equipment, an indicator of the residual resource is selected. The calculation of the residual resource, with the definition of its boundary values and recommendations for further use. Nominal energy efficiency parameters of autonomous electrotechnical complexes with electric drive deteriorate during operation, which also needs to be taken into account. To simplify the assessment of the operational state of electromechanical equipment, a state diagram is presented that allows you to track the dynamics of degradation of individual nodes. Taking into account the described indicators and means of control, it is possible to increase the efficiency of using autonomous complexes.