The research considers conducting orthogonal experiment (OT) as one of the stages in developing a new discrete element method (DEM) parameters calibration approach. The measured responses in experiment are the parameters obtained by DEM animation processing using machine vision system (MVS). The variable factors in experiment are DEM parameters. A brief overview of an existing calibration approaches given in the article. The choice of OT as a design of experiment tool among other mathematical tools discussed. Experiments conducted using specially developed rig where bulk material's flow captured as DEM animation. DEM animation converted to video and then processed using MVS that allow register the values of such parameters as angle of repose or expiration time (measured responses). The results of the OT show that it is possible to identify four measured responses with the most valuable correlation coefficient. DEM parameters with the biggest influence on the measured responses identified for each of the obtained regression. Obtained results are useful in learning or iterative algorithms development for DEM parameters calibration.

The immediacy of the problem under study is due to the fact that the devices for extraction of solid mineral deposits from the offshore fields are not effective enough and do not meet modern requirements regarding safety, productivity, energy intensity and environmental friendliness nowadays. The purpose of the article is to analyze the influence of hydrostatical pressure, determined by the depth of the capsule location, on the operational and energy characteristics of the proposed mining equipment and the dependence of system performance on the type of a dredge head and its parameters. The leading approach to analyzing this problem was the theoretical study of the processes of hydraulic hoisting and separation of nodules from the bottom, as well as experimental studies of the applied hydraulic motor parameters on the laboratory bench with the processing of results via the mathematical statistics methods and verification of the adequacy of theoretical provisions. As a result, it was found that the energy intensity of the nodule production process depends on the capsule location depth and varies according to the parabolic law; in this case, there is a mode of effective work of the facility to be determined by the model proposed in the article. It was also substantiated that the achievement of the facility performance required level is ensured by the application of a special dredge head, which has an annular channel between the driven hydraulic motor and protective cover, which geometrical dimensions are being determined with consideration for the maximum nodule size and required engine power. It has been experimentally proven that local resistances at the output of the driven hydraulic motor depend on the release coefficient when draining the power fluid into the environment. The materials of the article are of practical value for further studies in the field of determining a high performance technology for extraction of sea-bed solid mineral deposits, as well as during development of technical facilities for the underwater mining of nodules and other solid mineral deposits.

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