Methods of improving the coordinates determining accuracy using inertial geodetic systems

The authors consider the principle of geodetic definitions using inertial systems in the absence of signals from satellite radio navigation systems and insufficient density of the initial geodetic base. A technique of improving the coordinates’ accuracy determining using inertial geodetic systems is proposed. Compensation of these systems’ errors is performed through joint equalization of data received from the inertial system, gyrotheodolite and rangefinder. In order to test the methodology, a mathematical model of the ground object movement with an inertial geodetic system was compiled. The simulation results confirm the suitability of the developed methodology. A full-scale experiment was conducted to test the efficiency of the technique. Its results are consistent with those of the simulation. The analysis of the data obtained enables concluding that the developed technique provides an increase in the accuracy of determining coordinates using inertial geodetic systems in the absence or distortion of signals from satellite radio navigation systems and insufficient density of the initial geodetic base. That is why it can be used in operational geodetic training under conditions of autonomy.

Development of the computer model of the plasma installation

Mathematical model of a plasma installation for the production of metal powder and coating has been developed. The problem of creating an objective mathematical model of the plasma jet flow is solved, which adequately describes the real process and allows predicting the parameters of the plasma jet. The value of the temperature of the plasma jet at a characteristic point located on its axis is investigated. The computer model was verified by carrying out a full-scale experiment. Comparative analysis of the results of numerical and field experiments showed satisfactory convergence. It is shown that the temperature of the plasma jet flow obeys the normal Gaussian distribution. The research results can be used to improve processes and technological equipment.

STUDY ON PIPE WEAR BASED ON LARGE SCALE EXPERIMENT AND SCALE EFFECT FOR DEEP SEA MINING

For the production of seafloor massive sulfides, the ores are expected to be transported as a slurry up to the sea surface. The pipe wear is caused mainly by the collision of the ores against the pipe wall, thus the evaluation of pipe wear is required for the operation of the production system. The authors conducted a full-scale experiment for evaluating pipe wear due to slurry flow. As the results, the pipe wear resistance of a SUS304 stainless steel is higher than the ultra high molecular weight polyethylene. In addition, the pipe wall thickness was measured before and after the experiment to obtain the distribution of the erosion on the pipe wall. The authors confirmed that the wall thickness reduced uniformly along the circumferential direction for vertical pipe, and the erosion occurred mainly along the bottom surface of the pipe for the horizontal and inclined pipes. Also, the authors investigated the relation between the index of the rock abrasivity and erosion and proposed a correlation for the pipe wear with the index of rock abrasivity. Finally, the authors predicted the pipe wear on the condition of full-scale experiment based on the data obtained in the reduced-scale experiment conducted previously. Then the authors compared the predicted pipe wear with that measured in the full-scale experiment.

Influence of the Form Factor on the Results of the Fracture Process Modeling under Uniaxial Tension

This paper provides a comparative assessment of the results of modeling the processes of deformation and destruction of objects under uniaxial tension in the MSC.Marc and DEFORM software packages and in a full-scale experiment, as well as a study of the influence of the form factor of these objects and the form of unit cells on the fracture parameters in modeling and experiment.