CALCULATION-THEORETICAL STUDY OF CHARACTERISTICS OF THE TWO-PHASE FLOW IN A SANDBLASTING MACHINE

The paper considers the possibility of conversion applying of a rocket engine as a sandblasting machine for thermo-abrasive treatment. The higher performance characteristics of a treated surface can be achieved through the exposure of the high-temperature two-phase flow accelerated in the device nozzle barrel on the object. The ejection feed of granular abrasive substances determines the relative structural simplicity of the device structure. The authors prove the efficiency of such a device using the gas-dynamic process modeling in the CFD software package, the calculations of which are based on combined equations including the key parameters of both the carrier gas and the solid phase particles. The process modeling considers the influence of the geometry and the specifics equal to the real operating prototype. During further analysis, to determine the optimal mode, the authors investigated the influence of various border conditions on the supersonic two-phase flow. The study considers the mutual influence of gas flow and abrasive solid particles starting from the powder delivery section to the nozzle outlet section. The study presents the comparison of temperature and pressure fields depending on the input values, as well as the fluid velocity fields based on these values. The authors carried out the analysis of the dependence of solid particle motion speed on the coordinate at various initial data of temperature and pressure. The study pays special attention to the consideration of the impact of the k -phase particle size on the speed parameters. During the study, the authors identified the main methods of device adjustment to achieve the required mode parameters. As a result of the analysis, the paper concludes on the efficiency and competitive ability of the thermo-abrasive treatment method under the study.

thermo-abrasive treatment, sandblasting machine, supersonic ejector, two-phase flow, finite volume method