bluuebunny/crossref_metadata_2025_split huggingface dataset:
An early stage of the drop interaction with shock wave: airflow, deformation, destruction
Authors: Poplavski S V , Minakov A V , Shebeleva A A 
Published: November 2019

Abstract
The work is devoted to experimental and computational modeling of the flow around water droplets behind an incident shock wave and its effect on deformation and decay. The structure of the flow near and in the wake of the drop, the evolution of the shape and breakup delay were investigated in the range of shock wave Mach numbers Ms=1.109–1.34 and Weber numbers We=200–2200. Comparison of calculations with experiments allowed constructing a phenomenological picture of the behavior of a drop in shock wave as a response to a rapidly changing flow field at an early stage of interaction.
Study of the features of behaviour of overheated liquid-metal drops in gas media, water and electromagnetic field of the inductor
Authors: Vinogradov D A , Ivochkin Y P , Kubrikov K G , Sinkevich O A , Teplyakov I O 
Published: November 2019

Abstract
A modern experimental setup designed for the melting of liquid-metal samples by the eddy current is described. A new experimental material about the behaviour of drops of the melts in` gas atmospheres (argon, air) and distilled water of room temperature is obtained. It was confirmed that during the heating of a steel drop, that is the main component of corium in case of crashes at the nuclear power plants, in air an intensive spark generation of metal (drop erosion) are observed. The latter prevents the occurrence of the film boiling regime of the coolant and contributes to the prevention of explosive fragmentation of the melt. It is shown that in an inert argon atmosphere such regime does not take place but there is another physical effect that requires additional study and which is behind the ejection of the streams (or departure of drops) of liquid metal from its surface into the surrounding space. The relation between was determined the frequency of departure of coolant (distilled water) vapour bubbles and external pressure and temperature of the heated ball. It was stated that the regime of film boiling with the departure of vapor bubbles is observed only at temperatures over 350 °C. A figure with the changing form of the inter-phase vapor-liquid surface depending on the temperature of the heated body was obtained.
Optimization of stator blade profile design for last stages of steam turbines based on the features of coarse droplets movement in inter-blade channels
Authors: Alekseev R A , Gribin V G , Tishchenko A A , Yu Gavrilov I , Tishchenko V A , Popov V V 
Published: November 2019

Abstract
Results of the investigation of coarse droplets movement in steam turbine blade passages are presented in the paper. The structure of generated streams of secondary droplets was considered. The analysis of the effect of these streams on the liquid film formation on the blade surfaces was performed. On the basis of obtained data, several recommendations for blade design operating in wet steam conditions were formulated. They were used to optimize the baseline profile geometry in order to control the coarse droplets streams and provide the increasing of liquid film suction effectiveness. The numerical and experimental comparison of the baseline and optimized geometries was performed.
Theoretical investigation of nitrogen gas hydrates outside of stability zone
Authors: Zhdanov R K , Gets K V , Bozhko Y Y , Subbotin O S , Belosludov V R 
Published: November 2019

Abstract
Using a combination of Quasiharmonic Lattice Dynamic and Molecular Dynamic Simulation methods in conjunction with well developed statistical thermodynamics theory the thermodynamic properties of nitrogen gas hydrates has been calculated, with the main focus on the thermal expansion coefficient. It is shown that nitrogen gas hydrate displays larger value of the thermal expansion coefficient in comparison with hexagonal ice Ih and empty gas hydrate lattice, moreover this value is very close to one of the carbon dioxide and to other hydrates that have self-preservation effect. Exactly because of this difference in the thermal expansion coefficient it is possible to confirm existence of the self-preservation effect. The self-preservation effect can be used for creation of low-cost technology of hydrates storage and transportation technology applicable for many gas types.
Heat and mass transfer during crystal growing by the Czochralski method with a submerged vibrator
Authors: Fedyushkin A I 
Published: November 2019

Abstract
It was shown that the vibrations can intensify of heat- mass transfer and mixing of the melt, and also to reduce dynamic and temperature boundary layers and to increase a temperature gradient on melt/crystal interface, that can to increase rate of crystal growth by the Czochralski method with a submerged vibrator. It is can be very impotent for manufacturing and quality of crystals.
Sedimentation dynamics of a polydisperse cluster of solid particles in a viscous fluid
Authors: Arkhipov V A , Basalaev S A , Zolotorev N N , Perfilieva K G , Usanina A S 
Published: November 2019

Abstract
Methods and results of experimental studies of the gravitational sedimentation of a consolidated polydisperse system of solid spherical particles in a viscous fluid are presented. The overall picture of motion of the consolidated system of bi-disperse solid spherical particles is obtained. The motion regularities (the cloud evolution, sedimentation rate, and drag coefficient) of a set of solid spherical particles under various flow regimes are investigated. The gravitational sedimentation of monodisperse and bi-disperse consolidated systems of spherical particles in the viscous fluid is compared.
Numerical Simulation of Coaxial Swirled Lifted Propane-Air Flame under Buoyancy Conditions
Authors: Evdokimov O A , Guryanov A I , Veretennikov S V 
Published: November 2019

Abstract
Numerical simulation of gas dynamics and combustion in coaxial swirled lifted propane-air jets under buoyancy conditions is performed. Dependences of dimensionless flame length L/d
0, lift-off height h/d
0 as well as flame front surface area Sfl
and mass rate of burn-out U on orientation angle θ are obtained. The results of numerical simulation and experiment for different values of θ are compared. It is confirmed that in the angle range of 30° < θ < 60° flame has the smallest surface area that provides the highest value of the mass rate of burn-out. The numerical solution closest to an experiment data can be obtained by using an additional differential transport equation for the ignition time or setting a delay time in the range of 0.05..0.25 s.
Numerical study of two-dimensional structure of detonation front in two-fuel mixtures
Authors: Trotsyuk A V 
Published: November 2019

Abstract
The numerical simulation of a two-dimensional multi-front structure of detonation waves (DWs) in two-fuel mixtures has been carried out. These studies are based on the proposed two-stage generalized model of chemical kinetics of detonation combustion of a two-fuel mixture: hydrogen and carbon monoxide (synthesis gas) with an oxidizer. This kinetics allowed performing for the first time a two-dimensional numerical calculation of the DW parameters and the irregular cellular front structure in this two-fuel mixture at various concentrations of hydrogen. Stoichiometric compositions with oxygen and air as oxidizing agents have been studied. The transverse sizes of detonation cells in the studied mixtures have been obtained. The decrease in the hydrogen concentration leads to a significant increase of the cell size and an increase of the degree of irregularity of DW multi-front structure.
Comparison of crystallization behavior in a drop and in a thin layer of an aqueous salt solution of LiBr during non-isothermal desorption
Authors: Misyura S Y , Morozov V S 
Published: November 2019

Abstract
An experimental study of the motion of the crystal front and the crystallization rate for a drop and a layer of an aqueous salt solution of LiBr was carried out. The nature of the crystal front motion depends on the initial salt concentration. For most of the crystallization time, the crystallization rate J
cr is many times higher for a drop than for a thin layer. For the final crystallization stage, J
cr is higher for the drop. Different crystallization kinetics is associated with a change in the place of origin of the first crystalline center, as well as with features of the temperature distribution on the free surface of the salt solution.
Study of the formation of the Black Sea haline stratification from the numerical simulations
Authors: Senderov M V , Mizyuk A I , Korotaev G K 
Published: November 2019

Abstract
The excess of river runoff and precipitation over evaporation (positive freshwater balance) and the supply of the Marmara Sea highly saline waters through the Bosphorus is the cause of the sharp halocline in the 100-300 m layer and low vertical mixing in the permanent pycnocline layer, where the contribution salinity to the seawater density prevails compared to temperature. Such features of the Black Sea waters make the description of the process of formation of the haline stratification an actual and inexhausted problem. Investigating the patterns of the formation of the haline stratification in the Black Sea, a laboratory model of a rotating cylindrical cavity and a numerical model are proposed. Laboratory studies have shown that in a simple configuration, the buoyancy flux across the basin boundaries leads to the formation of a sharp pycnocline and the formation of a three-layer vertical structure of horizontal currents. Numerical experiments demonstrate that halocline is formed at a depth of 10-40 m. The haline stratification has been established with a pronounced halocline for about hundred years which later slowly evolved.
Numerical modeling of the Kolmogorov flow in a viscous and inviscid media
Authors: Fortova S V , Oparina E I , Doludenko A N 
Published: November 2019

Abstract
In this paper we consider the problem proposed by A.N. Kolmogorov to study the reasons of turbulence. We consider the action of the external periodic field along one of the coordinates on a viscous and inviscid conductive media in the two-dimensional case. We propose a numerical study of this problem based on the solution of the systems of the Euler and mainly the Navier-Stokes equations. The calculations show that under certain conditions periodic vortex structures may appear in the liquid, similar to the “parquet” mode in the Kolmogorov task, with the subsequent development of the self-similar regime.
Dynamics of gas phase concentration in SPH
Authors: Davydov M N 
Published: November 2019

Abstract
Various approaches are considered in the method of smoothed particle hydrodynamics (SPH) for calculating the volume concentration of gas phase in a liquid during the rarefaction or destruction. A scheme for calculating the concentration of gas phase, consisting of three stages, is proposed. At low concentrations, the calculation is carried out according to the full model, which includes the laws to describing the concentration dynamics. At high concentration the simplified model is used, when the change in concentration is determined by the dynamics of liquid. When the maximum concentration is reached, corresponding to a single particle without neighbors, the rate of concentration growth is fixed and the further development of the process is governed by inertia.
The expansion of the dynamic range of photodetectors in hydrodynamic research using active optical shutters
Authors: Rakhmanov V V , Anikin Yu A , Kulikov D V , Pavlov V A , Schepikhin I V 
Published: November 2019

Abstract
The implementation of the method expanding the dynamic range of photodetectors in hydrodynamic experiments based on the use of active optical shutters is presented. A method that allows using modern CMOS cameras as optical radiation receivers and laser emitters as illuminators has been developed. The attenuation coefficients of linearly polarized light on the photodetector has been measured. An experimental estimate of the expansion of the dynamic range in terms of the intensity of the received radiation in the presence of background highlights has been made.
Determining kinetic constants for reactions of zinc oxide sorbents with syngas components
Authors: Kagramanov Y A , Ryzhkov A F , Tuponogov V G , Nikitin A D 
Published: November 2019

AbstractHot gas clean-up (HGC) technology uses special zinc oxide based sorbents. Sorbent attrition is one of the negative factors that should be improved. The current study has determined that one of the main reasons of sorbent reduction is interaction with syngas components, namely, carbon monoxide, hydrogen, methane and carbon (side reactions). In this study, kinetics of main reaction (h2s adsorption by zinc oxide) and side reactions were considered and compared. Models of chemical processes and mechanisms were considered as well. Complicated nature of HGC process was researched. It is stated that the process can run in three different phases (gas, solid, dust). Methods of TGA data calculation are presented and compared with literature. In syngas where hydrogen sulphide concentration is much lower than concentration of hydrogen and carbon monoxide, main reaction is dominant at temperatures near 300–500 °C. At 650 °C main reaction takes the second place after H2reduction, and at 850°C it is the third after CO reduction (with diffusion resistance of product shell). Hydrogen reduction is more active than carbon monoxide reduction, that is why CO/H2ratio in syngas should be increased for rising the HGC operation temperature. A wide range of processes (main and side reactions) was considered with the use of the same materials, equipment and methods.
Thermal conductivity of CsBi alloy in liquid state
Authors: Sh Agazhanov A , Savchenko I V , Abdullaev R N , Stankus S V 
Published: November 2019

Abstract
Experimental data on the thermal conductivity and thermal diffusivity of a liquid alloy CsBi of the equiatomic composition in the temperature range from the liquidus line to 1173 K have been obtained. The measurements were carried out on the basis of the laser flash method using a sealed steel cell. For studied properties the approximation equations and a table of recommended values are presented. The analysis of the obtained results confirms the existing assumption about liquid cesium-bismuth alloys as associated solutions.
Morphology and optical properties of films based on CVD graphene and nanostructured gold
Authors: Boyko E V , Smovzh D V 
Published: November 2019

Abstract
In the work presented, the polymer-graphene-gold composites obtained by the methods of chemical vapor deposition and pulsed laser ablation (PLA) are studied. The morphological and optical properties of the given samples are studied in detail. It is shown that with an increase in the number of laser pulses in the PLA method, the metal coating transforms from separate small gold particles to a continuous cover with the presence of large nanoparticles. It is shown that a change in the gold film thickness influences significantly the efficiency of plasmon attenuation of a signal: with an increase in the average mass thickness, the effect increases and reaches its maximal value at film thickness of 6 nm. It is shown that the most intense plasmon absorption occurs in the wavelength range from 550 to 750 nm. A further increase in the thickness of metal coating decreases sample transparency in the studied range and does not affect the intensity of plasmon absorption and scattering.
Calorical properties of equiatomic alloy of rubidium-bismuth system in the temperature range 293–1175 K
Authors: Stankus S V , Savchenko I V , Yatsuk O S 
Published: November 2019

Abstract
The caloric properties of the Rb50Bi50 alloy were experimentally investigated in the temperature range 432.6-1176.8 K with the errors of 1.3% for enthalpy and 0.4% for heat capacity. The enthalpy change on melting was 8844 J mol-1. It is shown that the heat capacity of the melt decreases linearly with overheating above the liquidus and significantly exceeds the heat capacity of the ideal solution. Tables of recommended values of caloric properties over the range from 298.15 K to 1175 K were developed.
Studying the thermophysical and physicochemical properties of solutions of boric acid for emergency core cooling of WWER
Authors: Sahipgareev A R , Morozov A V 
Published: November 2019

Abstract
The results of experimental research of physicochemical (degree of acidity - pH) properties of aqueous solutions of boric acid are presented in this paper. A review of available literature data about the influence of properties of boric acid solutions on heat removal from the reactor core is given. It has been established that the available information is very general in nature and does not cover the entire range of parameters (temperature, pressure, acid concentration) characteristic of a possible emergency situation at NPPs with a WWER reactor. Experimental techniques and test facilities for research are described. The experimental data of the pH of aqueous solutions of boric acid in range of the concentration (5-100 g kg-1 H2O) and temperature (25-50 °C) are received. The approximating dependence for the degree of acidity of aqueous solutions of boric acid has been obtained.
Room temperature testing of PLA plastics
Authors: Vendland L E , Volkov-Muzylev V V , Demidov A N , Borisov Yu A 
Published: November 2019

Abstract
Polylactide plastic (PLA) prototypes are studied by means of additive technology to determine their strength properties in case of tension along the grain. In this article, testing of PLA and its compound PLA HP was carried out. Mechanical properties (yield limit, Poisson’s ratio, Young’s modulus) are determined. Analysis of results related to comparison of PLA and PLA HP was realized. Plastic is also studied using microscope for determination of adhesion influence on strength characteristics.
Three-dimensional modeling of the viscous fluid flow and the dynamics of dispersed systems in microstructures using the boundary element method
Authors: Abramova O A , Pityuk Yu A , Gimadeev A V , Iskandarov A I 
Published: November 2019

Abstract
Direct simulation of viscous fluid flow and dispersed flow at low Reynolds numbers in microstructures with complex geometry is needed for a wide range of industrial applications associated with the porous materials. The numerical approach is based on the boundary element method (BEM) for 3D problems accelerated both via an advanced scalable algorithm (FMM), and via utilization of a heterogeneous computing architecture (multicore CPUs and graphics processors). This enables direct large scale simulations on a personal workstation, which are confirmed by demo computations. In present work, the hydrodynamic flow of viscous liquid around the rigid structures with various configurations is studied. Also, the numerical approach is successfully applied for modeling the dynamics of deformable dispersed inclusions in the flow around microstructures. The results of the research may be used for the solution of problems related to microfluidic device construction, the theory of the composite materials production, and are of interest for computational hydrodynamics as a whole.
Experimental investigation of laminar forced convection of nanofluid in heat exchange equipment
Authors: Guzei D V , Minakov A V , Pryazhnikov M I 
Published: November 2019

Abstract
The laminar forced convection in a recuperative heat exchanger operating with nanofluids with MgO nanoparticles was investigated experimentally. In the experiments, nanoparticle concentration varied in the range from 2.5 to 12 wt. %. The nanoparticle size equalled 50 nm. The viscosity and thermal conductivity coefficients of the nanosuspensions were experimentally determined. The dependence of the average heat transfer coefficient and pressure drop on the Reynolds number for nanofluids was obtained.
Comparison of the forecasting results of Black Sea surface temperature obtained in the FSBSI MHI and Copernicus marine environment monitoring service
Authors: Kholod A L , Ratner Yu B , Ivanchick M V 
Published: November 2019

Abstract
The paper considers the matters of numerical modelling and forecast estimation accu-racy of sea surface temperature in the two monitoring and forecasting centers of the Black Sea – in Federal State Budget Scientific Institution «Marine Hydrophysical Institute of RAS» (FSBSI MHI) and Copernicus marine environment monitoring service. The CTD (Conductivity Temper-ature Depth) profiling data of in situ measurements from research vessel “Professor Vod-yanitskiy” were used to solve the problem. Spatial and temporal mismatch between the model data and in situ measurements was eliminated to form a joint sample of these two data sources. Comparison was performed for the time period from October 2017 to September 2018 and showed that the forecasting results of sea water temperature in FSBSI MHI are more reliable than in Copernicus marine service for all forecast terms.
Structure and properties of sintered Al-Cr-Zr alloy
Authors: Agureev L E , Savushkina S V , Laptev I N , Ivanov A V 
Published: November 2019

Abstract
Aluminum alloy Al-Cr-Zr was obtained by mechanical alloying and spark plasma sintering. The structure, tensile strength, and elastic properties at different chromium contents in the alloy were studied. The best properties both at room and at elevated temperature were shown by Al-0.5% Cr-0.3% Zr alloy samples (Young’s modulus ∼65 GPa, tensile strength ∼358 MPa). An increase in the Cr content in the composite to 1% leads to the formation of large chromium-containing inclusions (possibly coarse intermetallic compounds) along the grain boundaries of the alloy, which impairs the mechanical properties of the material.
Surface nanostructure evolution in carbon fiber under ion-induced corrugation
Authors: Andrianova N N , Borisov A M , Makunin A V , Mashkova E S , Ovchinnikov M A 
Published: November 2019

Abstract
The results of experimental study of the morphology evolution of carbon fiber VMN-4 based on PAN fiber depending on 30 keV Ar+ irradiation with exponential fluence decrease from center to periphery of ion beam spot on the target are presented and discussed. Scanning electron microscopy show a strong influence of ion fluence on the morphology, expressed by the transformation of nanoscale conical elements in a submicron corrugated structure.
Anodic plasma-electrolyte modification of Fe and Ti-based alloys
Authors: Belkin V S , Krit B L , Morozova N V , Ludin V B , Peretyagin P Yu , Suminov I V , Apelfeld A V , Bentseva E A 
Published: November 2019

Abstract
The anodic plasma-electrolyte modification of titanium alloy VT1-0 and low-carbon steel 20 for improvement their properties was carried out in nitrogen- and boronitrogen-containing electrolytes, respectively. Tribological and corrosion-protective properties of formed surface layers was investigated. The data of technical tests showing increase in the operational life of threaded fastening pair subjected toto plasma-electrolyte boronitriding are presented.
Structural features of titanium, aluminum and magnesium alloys with rare earth elements
Authors: Betsofen S Ya , Skvortsova S V , Grushin I A 
Published: November 2019

Abstract
The influence of rare earth elements (REE) on titanium, aluminum and magnesium, as well as doping systems based on them, is considered. The general regularities of REE influence on the mentioned titanium, aluminum and magnesium are revealed.
Effect of laser heat treatment on structure and wear resistance of cobalt stellite
Authors: Furman E L , Usoltsev E A , Bakhteev I S , Furman I E , Shak A V 
Published: November 2019

Abstract
The structure and wear resistance of Stellite 6 alloy were studied before and after laser heat treatment. A significant refinement of the microstructure after the heat treatment is noted, the hardness the alloy changed slightly. An increase of wear resistance in shock-abrasive wear at angles of attack of 60-90° as well as metal-to-metal wear with presence of an abrasive layer is shown.