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Исследованы нестационарные процессы истечения жидкости, вскипающей в результате разгерметизации сосудов высокого давления. Проведено обобщение двухфазной модели вскипающей пароводяной смеси на решение пространственных задач для случая осевой симметрии в односкоростном и однотемпературном приближениях и условии равного давления в фазах с использованием широкодиапазонного уравнения состояния воды и пара в аналитической форме. Численное моделирование двухфазных процессов реализовано на подвижных лагранжевых сетках с применением метода сквозного счета. Изучены особенности формирования струй вскипающей жидкости, образующихся в процессе внезапного истечения воды из сосудов высокого давления при различных значениях начальных параметров состояния насыщения, близких к термодинамической критической точке. Получено качественное согласование расчетных и экспериментальных данных.Ключевые слова: истечение вскипающей жидкости, математическое и численное моделирование, парообразование SPATIAL MODELING OF THE NONSTATIONARY PROCESSES OF BOILING LIQUID OUTFLOWS FROM HIGH PRESSURE VESSELS R.Kh. Bolotnova and V.A. Buzina Mavlyutov Institute of Mechanics RAS, Ufa, Russian FederationThe nonstationary processes of boiling liquid outflows following high-pressure vessel depressurization are studied. The two-phase model of a boiling vapour-liquid mixture is extended to solve spatial problems in the case of axial symmetry, where single velocity, single temperature and single pressure approximations are valid, using a wide range equation of state for water and steam in analytical form (R.I. Nigmatulin, R.Kh. Bolotnova). Numerical simulation of two-phase processes is implemented on moving (Lagrangian) meshes using the shock-capturing method. The peculiarities of formation of boiling liquid jets during the explosive outflow of water from high pressure vessels are studied for different initial state parameters of saturation close to the thermodynamic critical point. The calculated spatial distributions of volume vapour concentration and pressure and velocity fields are presented. It has been found that the jet has a conical form when the initial saturation temperature of water is below 480 K. A further increase in the initial saturation temperature up to the critical point leads to twisting of the jet against the flow direction and to its "sticking" to the sidewall, so that the cone opening angle increases to 180°. The values of supersonic and subsonic regimes of outflow are determined using the Mach numbers. Qualitative agreement between calculated and experimental data (A.V. Reshetnikov, N.A. Mazheiko, etc.) is obtained.

This paper is devoted to the selective laser smelting (SLS) method description for the article made of powder of a Cu81-Ni19 copper-nickel alloy and the study of the structure and characteristics of the three-dimensional article made using additive technology. To make a 3D model the copper-nickel alloy powder was produced in our laboratory. The chemical composition, microstructure, density, surface roughness and microhardness of an article made of powders of a Cu81-Ni19 copper-nickel alloy are considered. A comparative analysis of the structure, physical and mechanical properties of a sample obtained by the SLS method and the annealed rolled plate was carried out. The article microstructure is characterized by the absence of a typical signs of a crystalline structure and contains elements of a quasi-amorphous state. At the same time, the obtained material differs from the standard monolith billet with a lower surface roughness and a higher hardness values while maintaining almost the same density indices.

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