bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of low-Z impurity transport theory using boron perturbation experiments at ASDEX upgrade
Authors: McDermott R.M. , Angioni C. , Cavedon M. , Kappatou A. , Dux R. , Fischer R. , Manas P. , the ASDEX Upgrade Team  
Published: November 2021

Abstract
An experimental technique has been developed at ASDEX upgrade (AUG) to separately identify the diffusive and convective components of the boron particle flux. Using this technique a database of B transport coefficients has been assembled that shows that the normalized ion temperature gradient (

R
/

L

T

i

) is the strongest organizing parameter for both the B diffusion and convection and large

R
/

L

T

i

is a necessary ingredient to obtain hollow B density profiles in AUG. This database also shows that large changes in the applied neutral beam injection (NBI) have a relatively small impact on impurity transport compared to similar changes in electron cyclotron resonance heating (ECRH). Even low levels of ECRH power dramatically increase both the diffusive and convective fluxes and lead to peaking of the impurity density profile. Comparisons to a combination of neoclassical and quasi-linear gyrokinetic simulations show good agreement in the measured and predicted diffusion coefficients. The outward convection measured in NBI dominated plasmas, however, is not well captured by the simulations, despite the inclusion of fast ions. In contrast, the convection is reasonably well reproduced for plasmas with flat or peaked boron density profiles. This dataset provides an excellent experimental validation of the non-monotonic, predicted, convective-particle-flux created by the combination of pure-pinch, thermo-diffusion, and roto-diffusion. In addition, this dataset demonstrates a non-monotonic dependence of the experimental particle diffusivity to ion heat conductivity (D/χ
i) in qualitative agreement with theoretical predictions.
Eddy resolving simulation of mixed convection in a rotating annular cavity with one heated disk and axial throughflow: the effect of the surface macro-relief
Authors: Abramov A G , Zaitsev D K , Smirnov E M , Kitanina E E 
Published: November 2021

Abstract
We present the results of hybrid RANS/LES computations of non-isothermal buoyant flow in a rapidly revolving enclosure with paraxial transit stream of the cooling air. Foil heat flux meters mounted on the disk surface in the base experiment are mimicked by means of the grid resolved macro-relief. The results obtained using the relief and smooth disk models are collated with available measurements. According to the simulation, the addition of the relief has resulted in switching from two to three pairs of cyclonic/anti-cyclonic global circulations, and the overall heat transfer rate has increased by 20%. It has been found also that the sensor readings can be up to 25% higher than the heat flux averaged over the circumference at the same radius. Despite this distinct effect of the surface relief, the local heat transfer rate is still underestimated considerably as compared to measurements.
Conjugate heat transfer numerical study of the ejector by means of SU2 solver
Authors: Brezgin D V , Aronson K E , Mazzelli F , Milazzo A 
Published: November 2021

Abstract
In this paper, the test supersonic ejector with conjugate heat transfer in solid bodies has been studied numerically. An extensive numerical campaign by means of open-source SU2 solver is performed to analyze the fluid dynamics of the ejector flowfield accounting for the heat conduction in solids. The fluid domain simulation is carried out by employing compressible RANS treatment whilst the heat distribution in solids is predicted by simultaneous solving the steady heat conduction equation. The working fluid is R245fa and all simulations are performed accounting for real gas properties of the refrigerant. Experimental data against numerical results comparison showed close agreement both in terms mass flow rates and static pressure distribution along the walls. Within the CFD trials, the most valuable flow parameters at a wall vicinity are compared: distribution across the boundary layer of the temperature and the turbulent kinetic energy specific dissipation rate, boundary layer displacement and momentum thicknesses. A comprehensive analysis of the simulation results cases with adiabatic walls against cases with heat permeable walls revealed the actual differences of the flow properties in the wall vicinity. However, the ejector performance has not changed noticeably while accounting for the heat conduction in solids.
Enhancement of heat transfer at boiling in electrohydrodynamic flow
Authors: Chernica I M , Bologa M K , Motorin O V , Kozhevnikov I V 
Published: November 2021

Abstract
The influence of the electric field strength and interelectrode spacing on the heat transfer intensity at boiling in an electrohydrodynamic flow was studied. It was stated that the heat transfer coefficient increases with the increasing of the field strength. The influence of the interelectrode spacing is ambiguous. The efficiency of the action of a electrohydrodynamic flow on the heat transfer intensity at boiling was evaluated using the ratio of the heat transfer coefficient at boiling in the field to the heat transfer coefficient at boiling without the field. The relationships for calculation were obtained that satisfactorily agree with the experimental data.
Anomalous intensification of separated flow and heat transfer in one and multiple row deep inclined oval trench dimples on the wall of a narrow channel and on the plate
Authors: Isaev S A , Leontiev A I , Son E E , Guvernyuk S V , Zubin M A , Mikheev N I , Popov I A , Nikushchenko D V , Sudakov A G 
Published: November 2021

AbstractAt the stands of Research Institute of Mechanics at the Moscow State University, we experimentally confirmed the mechanism of anomalous intensification of the separation flow and heat exchange in inclined oval-trench dimples (OTD) on the plate, which was discovered during numerical studies. The measured static pressure differences in single OTD at Re=6.7×104 are in good agreement with the numerical forecasts within the framework of the RANS approach at Re=104.
Liquefied natural gas (LNG) and DC electric power transfer system by cryogenic pipe of superconducting DC power transmission (SCDC)
Authors: Yamaguchi Sataro , Ivanov Yury , Sugiyama Linda 
Published: November 2021

Abstract
We propose a hybrid energy transmission pipeline that combines the liquefied natural gas (LNG) cryogenic pipelines and superconducting direct current (DC) electrical power transmission cable system (SCDC). The system design is based on experimental data from the SCDC Ishikari project in Japan and related laboratory experiments. The particular structure of the hybrid cryogenic pipe connects the thermal radiation shield of the pipe that contains the DC high temperature superconducting (HTS) electrical cable to the LNG pipe and significantly reduces the heat leak into the SCDC pipe. Because the specific heat of LNG is higher than that of liquid nitrogen and the LNG transfer rate is quite high, the thermal loss of the SCDC cable becomes only 1/100 that of present-day conventional copper cables, far below the factor 1/10 reduction achievable by a stand-alone SCDC transmission lines. The LNG temperature rises by less than 2 K over a 100 km transport distance, which is negligible in actual use. LNG also saves significantly on pumping power compared to a natural gas pipeline. To liquefy the LNG at cryogenic temperature from natural gas at ambient temperature requires a large refrigerator that consumes enormous power. The gas pipeline, however, needs a compressor to produce high-pressure gas, which also consumes a massive amount of power. Due to these considerations, the proposed hybrid system is a viable design for the long-distance joint transportation of LNG and electricity.
Intensification of heat transfer in the inlet of the convective stage of the recuperative-burner unit
Authors: Leukhin Yu L , Alekseev P D 
Published: November 2021

Abstract
The study of aerodynamics and heat transfer in the recuperator convective stage of the recuperative-burner unit with the jet leakage of the flue gas flow onto the outer cylindrical surface is carried out. Numerical modeling of the problem was carried out in a three-dimensional formulation using the ANSYS Fluent software package. It was found that in the original design of the recuperative-burner unit, there is a significant unevenness of heat transfer along the length and perimeter of the working surface of the convective stage. In the initial section of the annular gap, a stagnant zone with the lowest heat transfer rate is observed. To eliminate the stagnant zone and to intensify heat transfer on the surface in this area, it is proposed to make the entrance to the perforated pipe in the form of an inner quarter of a torus; to install smooth protrusions on its surface; to locate an annular flow divider on the inner surface of the heat transfer wall, which separates the front part of the annular channel with formation of a set of vortex chambers. The research results are presented.
Measurement of velocity in swirling flows of liquid metals in the presence of a magnetic field
Authors: Listratov Ya I , Kolesnikov Yu B , Belyaev I A , Sviridov E V , Krasnov D , Zikanov O 
Published: November 2021

Abstract
Studies of the dynamics of a round submerged jet of liquid metal in a transverse magnetic field. The experiments were performed in the range of Reynolds numbers up to 1000 and Hartmann numbers up to 1300 using a probe technique for measuring velocity using potential sensors. Detailed three-dimensional flow structures are visualized using a direct numerical simulation method independent of the experiment. The paper presents data on the averaged velocity field and statistical characteristics of the flow, reproducing the complex nature of a substantially unsteady flow, in which zones of reverse fluid flows are detected and a significant heterogeneity of the velocity field is observed.
Evaluation of melt-water premixture formation due to Rayleigh-Taylor instabilities
Authors: Melikhov V I , Melikhov O I , Finoshkina D V 
Published: November 2021

Abstract
A linear analysis of the stability of the three-layer stratified hydrodynamic system “water (top) – steam – melt (bottom)” has been performed. Kinematic and dynamic conditions on the “water – steam” and “steam – melt” interfaces are formulated, and on their basis a dispersion equation is obtained that relates the circular frequency of perturbations to the wavenumber. Analysis of this equation made it possible to determine the region of instability of this system and to find the wavenumber of the most fastly growing harmonics. The results obtained were used to estimate the size of bubbles formed at the interface between steam and water due to the development of the Rayleigh-Taylor instability. The obtained theoretical results are consistent with experimental observations in such systems. The heights of the melt splashes into water due to the collapse of the formed steam bubble were estimated. The obtained estimations demonstrate possibilities of the formation of melt-water mixture region during the spreading of the melt under a water layer, in which a strong steam explosion can occur.
Investigation of the direct-flow jets vortex motion in the M-shaped boiler invert furnace
Authors: Prokhorov V B , Kirichkov V S , Chernov S L , Kaverin A A , Fomenko N E 
Published: November 2021

Abstract
For advanced ultra-supercritical parameters (A-USC) of steam, the design of an M-shaped boiler is proposed, designed to operate in a 500 MW unit on a lean coal (grade TR). The boiler profile is selected from the condition of minimizing the length of the main steamlines made of expensive nickel-alloy steel. With regard to this boiler, a scheme has been developed for pulverized coal combustion in an invert furnace using direct-flow burners and nozzles. Research has been carried out on the physical model of the furnace in the implementation of this combustion scheme: a qualitative study of the trajectories of the burner jets, jets of secondary and tertiary air obtained by their hot spark visualization; quantitative determination of the main characteristics of burner jets and their weight gain. The studies have shown the high efficiency of the recommended scheme of the furnace-burner device: a staged supply of the oxidizer along the flame length and along the furnace height is organized; the dynamic pressure of jets on the furnace wall tubes is excluded; vortex furnace aerodynamics should provide a high degree of burnout of coal dust particles; air jets evenly fill the horizontal section of the furnace; the ejection capacity of turbulent jets is much higher than for a flat submerged jet.
Development and verification of methods for predicting the frequency of self-oscillations in swirling coolant flows of nuclear power plants
Authors: Proskuryakov KN , Anikeev AV 
Published: November 2021

Abstract
Methods and algorithms for calculating the frequency of self-oscillations in swirling coolant flows of nuclear power plants with VVER reactors have been developed. The frequency of self-oscillations occurring in the acoustic sections of the primary circuit and their connections in the starting modes of the power unit and when operating at the rated power level is predicted. It is established that the self-oscillation frequencies can fall into the frequency bandwidth of mechanical vibrations and vibrations of the reactor plant’s internal devices. It is shown that in order to prevent the resonance of self-oscillations of the coolant with the vibration frequencies of internal devices, it is necessary and sufficient to take the frequency of self-oscillations outside the bandwidth of the vibration frequency of structures. The results of verification of the results of forecasting the frequency of self-oscillations in swirling coolant flows at a nuclear power plant unit with VVER are presented. The application of the developed technique shows that the pendulum oscillations of the VVER - 1200 body are caused by an increase in the parameters of the coolant and the geometric dimensions of the VVER - 1200 reactor compared to VVER-1000.
Numerical simulation of the branching blood flow in a model of the femoral artery-graft junction
Authors: Sherstneva M A , Smirnov E M , Yukhnev A D , Vrabiy A A 
Published: November 2021

Annotation
The results of numerical simulation of pulsating blood flow in a three-dimensional model of the femoral artery-graft junction are presented. The study is focused on the influence of the flow rates ratio in two branches of the branching flow on the location and size of the recirculation flow areas in the shunt and in the common femoral artery, with an emphasis on the analysis of the anastomotic zone. Areas with small values of the cycle-averaged shear stresses and increased values of the shear stress oscillation index, potentially dangerous from the point of view of the neointima growth in the shunt, are identified.
Thermal physical processes during forming of biocompatible Ca-P coatings by detonation spraying
Authors: Skriabin A S , Shakurov A V , Vesnin V R , Tsygankov P A 
Published: November 2021

Abstract
Carbon-carbon composites with calcium phosphate (Ca-P) coatings (with a thickness up to of ≈100 μm) are considering as prospective grafts for defect bone substitution. Detonation spraying of Ca-P layers allows to fulfil a deposition mode with relative low temperature loads (up to a temperature of the processed surface of ≈850…1100 K) under a pulsed pressure of ≈2…6 bar. Such deposition conditions could promote to minimal thermal decomposition of feedstock HAp.
Investigation of the saturated steam sampling method influence on the sample representativeness in chemical control systems at thermal power plants
Authors: Yegoshina O V , Zvonareva S K 
Published: November 2021

Abstract
The most important requirement for sampling is the sample representativeness, which is achieved by the design and location choice of sample nozzle, as well as the speed mode and the presence of sharp pressure drops in the saturated steam flow. The Ansys CFX software package simulates the sampling processes saturated steam in power units with low, medium and high pressure boilers which are used on operating thermal power plants. The saturated steam was sampled from low-pressure boiler by a single-strip probe with a Venturi nozzle, from the medium-pressure boiler was sampled by tapping a pipe at 90 to the main steam line, and the steam of the high – pressure boiler was sampled by a wellhead probe. In three sampling cases it is found that of saturated steam, the flow in the sample nozzle loses speed and decreases to values unacceptable for the selection of a representative sample-below tear rate of the moisture film from the surface. It is confirmed that in the industrial sampling conditions, the condition of speeds equality in the main steam line and in the sample nozzle is not met, which leads to a violation of the sample representativeness. The paper studies the change in the composition of the sampled saturated vapor sample after the film formation on the sample’s nozzle wall in relation to power units with ammonia dosing. It was found that the sample received by the chemical control analyzers is depleted due to the formation of a film and the ferrum and ammonia concentration in moisture droplets on the inner surface of the sampling line.
Development of the design of the research module - model of a high-temperature surface with induction heating
Authors: Varava A N , Demidov A S , Zakharenkov A V , Loktionov V D , Komov A T , Dedov A V 
Published: November 2021

Abstract
The paper describes a test bench for evaluating the cooling efficiency of a working area with a high energy density using a two-component dispersed coolant flow. The design of a pneumatic sprayer and the scheme of the working area cooled by a two-component dispersed flow are described. A description of the design of the new research module and a scheme for installing thermocouples on it is given. A method for measuring the temperature of the walls of the research module is proposed. Adjustment tests were performed at the operating parameters of the coolant p
water = 2,5·105 Pa, p
air = 2,0·105 Pa, G
water = 0,048 kg/c; G
air = 1,7·10−3 kg/c.
Features of metastable superheated water atomization when being discharged through convergent-divergent nozzles at different superheat values
Authors: Zalkind V I , Nizovskiy V L , Nizovskiy LV , Schigel S S 
Published: November 2021

Abstract
Experiments with the metastable superheated water atomization proved the significant increase of the submicron droplets mass fraction at the outlet of convergent-divergent nozzle from 0.45-0.55 to 0.75-0.9 with an increase of the inlet water temperature from170to255°C. Two different approaches to dimensionless treatment of the atomization processdata and determining the boundary of the zone of flashing predominance are compared. The analysis of two approaches to dimensionless treatment of experimental and calculating results concerning transition to predominating role of nucleation in the process of superheated liquid atomization in convergent-divergent nozzles is done.
Automated Solving Algorithm and Application for Oriented Bounding Box Based on Principal Axis of Inertia
Authors: Zhang Wenguo , Zhang Le , Lei Pei , Jin Xiaobo 
Published: November 2021

Abstract
In mechanical design and manufacture, the minimum size of raw material of each part should be measured before processing. Generally, this size could be equal to the size of minimum bounding box. When the assembled parts of a product reach an enormous quantity, the measurement would be a rough work. This paper introduced an automated solving algorithm for the oriented bounding box based on principal axis of inertia, combined with CATIA structural tree recursive traversal algorithm according to CAA V5 Automation API, to implement an automated solution of the engineering acceptable minimum oriented bounding box of CATIA model.
Minimum Disturbance Attitude Control Algorithm for DFFSR
Authors: Li Huazhong , Zhou Yanbing 
Published: November 2021

Abstract
Aiming at the attitude disturbance problem of Dual-arm Free Flying Space Robot(DFFSR), firstly, the kinematics equation of DFFSR has been established by using the geometric relationship of each link of DFFSR, the characteristic equation of manipulator, and the linear momentum and angular momentum conservation law of the system in microgravity environment; Secondly, based on the established Generalized Jacobian Matrix(GJM) describing the relationship between the end-effector motion velocity of DFFSR manipulator and the motion velocity of each joint, the relationship between the motion velocity of each joint of DFFSR manipulator and the angular velocity of satellite base has been derived, and the attitude interference model of DFFSR has been established; Finally, the Minimum Attitude Disturbance Map(MADM) algorithm for calculating the DFFSR manipulator has been established, and the attitude control algorithm based on MADM has been proposed. The attitude control method can ensure that the attitude of the satellite base of DFFSR remains unchanged during the movement of the manipulator.
Application of Controllable Splitting Grouting Technology in Loess Foundation Reinforcement
Authors: Liu Qingang , Zhou Mingru , Zhong Lin , Li Shaofei , Chen Yiming 
Published: November 2021

Abstract
Taking the foundation settlement accident of a large heating boiler foundation in a city in collapsible loess area as an example, controllable splitting grouting can be achieved by controlling the grouting pressure, grouting pipe opening form, grouting volume and grouting method etc., so as to stabilize foundation settlement and improve foundation bearing capacity, for the boiler with large uneven settlement, for boilers with large uneven settlement, quicklime piles are used to jack up the foundation after splitting grouting to stabilize the foundation, the foundation is lifted with quicklime piles after splitting grouting to stabilize the foundation. The results show that the grouting amount of soil is within the design range, the grout splits in the soil several times to form a slurry vein, the settlement is stable after boiler reinforcement, the quicklime method can jack up the foundation and reduce the uneven settlement of the foundation, and the use of controllable splitting grouting can basically eliminate the slight collapsibility grade loess, which provides a new idea for solving the similar problem of uneven settlement of collapsible loess foundation buildings.
Effect of Shell Temperature on Thermal Resistance and Junction Temperature for Power Diode
Authors: Chen Fan , Chen Long , Lian Pengfei , Liu Dapeng , Tao Shuai , Kong Zebin 
Published: November 2021

Abstract
Accurate measurement of junction temperature can avoid thermal failure of diode. During aging test, junction temperature should be indirectly calculated by testing its thermal resistance. In this paper, junction-to-case thermal resistance (Rthjc) of XX diode is tested by T3ster based on transient dual interface method. Its Rthjc is about 1.23K/W at 25°C and contains PN junction thermal resistance, metal shell thermal resistance and Sn-based solder thermal resistance, respectively. These three types of thermal resistance decrease in order. Effect of shell temperature on junction temperature and Rthjc is then discussed. As shell temperature increases, temperature variation of PN junction before and after heating and corresponding thermal resistance Rthjc both increase.