bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of heat transfer criterial equation when cooling aluminum ingots
Authors: Gorshenin A S , Krasnova N P , Rakhimova J I 
Published: November 2021

Abstract
A big problem when casting aluminum ingots is the uneven structure formation, which leads to an increased rejection of products. Nonequilibrium structure elimination is carried out by heat treatment. To obtain the required aluminum ingots’ physicochemical properties, it is necessary to know the conditions of heat transfer between the ingots and the cooling air, i.e. a mathematical model of conjugate heat transfer is needed. The mathematical model obtained by the authors makes it possible to analytically investigate the ingots temperature and cooling air during heat treatment. This mathematical model assumes the heat transfer coefficient calculation. The existing criterion equations for determining the heat transfer coefficient have a drawback - the heat transfer coefficient according to these equations is calculated in circular channels, while heat transfer between aluminum ingots and air occurs in rectangular channels. The article describes the criterion equation identification for heat transfer, used in the analytical study, by the data of the experimental study.
Aerodynamics and convective heat transfer processes in cyclone chambers with external recirculation of gases
Authors: Konoplev M , Onokhin D , Zagoskin A , Karpov S 
Published: November 2021

Abstract
The paper presents the results of an experimental and theoretical calculation study of aerodynamics and convective heat transfer on the side surface of cyclone recirculation furnace devices. The possibility of controlling the main aerodynamic characteristics without changing the geometric parameters of the cyclone devices by organizing external gas recirculation is shown.
Investigation of boiling heat transfer in microchannel of water and isopropanol
Authors: Kuzma-Kichta Yu A , Lavrikov A V , Shustov M , Kustova E A , Ivanov N S , Kuleshov E A , Kiselev A S 
Published: November 2021

Abstract
Boiling curves of distilled water and isopropanol in 12.5x3x0.2 mm microchannel with rigid inlet and outlet lines are obtained. Critical heat flux is calculated for isopropanol by using the previously obtained correlation for water.
Research of condensation induced water hammer under filling a horizontal pipe with subcooled water
Authors: Volkov G J , Melikhov V I , Melikhov O I , Nikonov S M , Selkin S S 
Published: November 2021

Abstract
Experiments at the KGU test facility, devoted to condensation induced water hammers (CIWH) were analysed with the WAHA code. Test section of the KGU test facility is slightly inclined horizontal pipe of 3 m length and of 64 mm inner diameter. Subcooled water was supplied to the pipe inlet, pipe outlet was connected to separator vessel. Upper part of separator vessel was connected to steam source. Experiments were performed for different system pressure, different water subcooling and different mass flow rate of water supply. The performed experimental study of CIWH showed that in the investigated range of parameters, the development of CIWH occurs in different ways. At the stage of water propagation along the filled with steam horizontal pipe, water hammer was not observed. At the stage of free drainage of water from the outlet end of the pipe, water hammer was realized only when the water was sufficiently subcooled. At the stage of the water level rise in the horizontal pipe, water hammer occurred in all tests. At the last stage of filling the upper part in the separation vessel, there were small water hammers due to the collapses of the remaining steam bubbles. Numerical modelling of these experiments with the WAHA code revealed the shortcomings of the interphase heat transfer model developed for this code, which have a noticeable effect on the numerical solution.
Influence of pipeline geometry on hydrodynamics and heat transfer processes by an example of a ship steam generator
Authors: Mitrofanova O V , Fedorinov A V 
Published: November 2021

Abstract
The theoretical and computational analysis proposed in this work is aimed at identifying the features of thermal and hydrodynamic processes carried out in the steam-generating channels of the ship type water-moderated nuclear power installations. It is shown that the complex geometry of the thermohydraulic tract curvilinear channels of the steam generating system has a significant effect on the efficiency of the transport nuclear power installation. In addition to the formation of large-scale vortex structures and swirling flow in the pipeline, the phenomenon of the swirling flow crisis is revealed, under which the low-frequency component of the acoustic spectrum is enhanced. The scientific and applied significance of the proposed research is associated with the need to ensure a wide range of operational changes in efficient and safe operation power modes of icebreaker nuclear power installations. The research, aimed at developing the principles of physical and mathematical modeling of complex vortex flows, is necessary to optimize the design parameters of the thermal power equipment elements of new generation ship nuclear power installations in order to ensure increased safety and reliability of their operation.
Numerical simulation of fuel staged swirl combustion in the invert furnace of boiler on advanced ultra-supercritical steam parameters
Authors: Prokhorov V B , Chernov S L , Kirichkov V S , Kaverin A A , Fomenko N E 
Published: November 2021

Abstract
The paper considers the schemes of Kuznetsky lean coal combustion for the M-shaped boiler. With such a boiler profile, it is possible to significantly reduce the length of main steamlines, which is especially important for the advanced ultra-supercritical parameters of the superheated steam. The furnace in this boiler unit is performed downward (invert). In this work, the aerodynamics of 6 combustion schemes was simulated by means of computational fluid dynamics. All considered schemes were designed on the basis of direct-flow burners and nozzles. For the most aerodynamically reasonable scheme the thermal processes in the boiler furnace firing Kuznetsky lean coal have been simulated by means of computational hydrodynamics. The simulation results showed a high efficiency of fuel burnout: loss due to unburned combustible equaled 0.1%, carbon-in-ash loss equaled 0.8%. Carbon monoxide concentration at the furnace outlet in conversion to excess air equal α = 1.4 amounted 226 mg/m3, the nitrogen oxides concentration in the flue gases (in conversion to normal conditions) equaled 424 mg/m3. It is appropriate to use the results obtained in this research in the development of new solid fuels combustion schemes.
3D-LDA diagnostics of a swirled flow in the model of an improved four-vortex furnace
Authors: Yu Shadrin E , Anufriev I S , Alekseenko S V 
Published: November 2021

Abstract
The three-component Laser Doppler Anemometry method (3D-LDA) was used to study the internal aerodynamics of an experimental model of a promising furnace with a four-vortex scheme for burning coal fuel. Distributions of the averaged velocity and velocity fluctuations are obtained. There are no the pronounced peaks in the spectrum of velocity fluctuations, so we can speak about the stability of the investigated flow. The studied model is characterized by a high level of velocity fluctuations, provided for effective mixing of the pulverized coal mixture in the combustion chamber of the furnace.
Kinetic approach to solution of evaporation-condensation problems taking into account multi-particle interactions in liquid
Authors: Shishkova I N , Kryukov A P 
Published: November 2021

Abstract
The presented work is devoted to the study of heat-mass transfer in vapor and liquid, taking into account multi-particle interactions in the condensed phase. An appropriate numerical procedure is proposed to solve the kinetic equation, both in the vapor and in the liquid. Using this approach, the problems of thermal conductivity in liquid argon, as well as the problem of evaporation-condensation, are solved.
Experimental efficiency evaluation of the of various geometry twisted bands for heat transfer intensification in the heat-exchange channels of a nuclear power unit equipment
Authors: Sobornov A E , Dmitriev S M , Ryazapov R R , Mamaev A V , Kotin A V 
Published: November 2021

Abstract
The paper is devoted to experimental study of heat exchange and pressure drop of channel with various geometry twisted bands. The studies were carried out in the range of operating modes parameters of the nuclear power units’ heat exchange equipment. The three different designs of intensifiers are presented in the paper. The values of heat transfer coefficient and pressure drop are obtained. The dependences of the Nusselt number (Nu) on the Reynolds number (Re) were calculated. The comparative analysis of intensifiers is made. The efficiency factor was also calculated on experimental data. The most optimal geometry form of intensifier was selected.
Studying of the characteristics of a single bubble under subcooled liquid boiling
Authors: Vasil’ev N V , Zeigarnik Yu A , Khodakov K A , Vavilov S N , Nikishin A S 
Published: November 2021

Abstract
An experimental study of the characteristics of single (solitary) bubbles obtained by means of focused laser heating of the surface during the boiling of two subcooled liquids with significantly different properties: water and refrigerant R113 has been carried out. To obtain the most complete detailed information, the technique of synchronized high-speed video filming of the process in two mutually perpendicular planes with a frame rate of up to 150 kHz was used. It is shown that during the boiling of a subcooled liquid, the main mechanism of heat removal from the bubble dome into the surrounding liquid is an unsteady heat conductance. Differences in the behavior of solitary vapor bubbles in the case of boiling of two liquids (water and refrigerant R113) are shown.
Features of intensive evaporation of liquid-metal steel drops heated in a high-frequency inductor
Authors: Vinogradov D A , Glazkov V V , Ivochkin Yu P , Kubrikov K G , Teplyakov I O , Sinkevich O A , Borodina T I 
Published: November 2021

Abstract
The paper presents the results of experimental studies of the processes of intense melting in air of samples (solid balls) made of metals, primarily various steels. It is shown that the heating of some steels is accompanied by intense sparking - the ejection of small secondary droplets (sparks) from the primary droplet heated up to 2500 K into the surrounding space. A possible mechanism of this process is proposed and described at a qualitative level. Possible reasons for the explosive fragmentation of secondary droplets are indicated and experimentally confirmed. The vibration process of molten samples shell, caused by the vortex motion and evaporation of the melt inside the droplet, is described. The influence of spark formation on the stability of the induction melting process is demonstrated.
Conjugated Heat Exchange in Heat Treatment of Aluminum Ingots Simulation
Authors: Gorshenin A S , Rakhimova J I , Krasnova N P 
Published: November 2021

Abstract
Casting aluminum to obtain semi-finished products - round ingots, due to uneven cooling in the mold, leads to various defects that affect further machining. To eliminate such defects, heat treatment is carried out - homogenization annealing. One of the homogenization important stages is the cooling of the ingots after heating at a rate that does not lead to the ingot quenching. The cooling medium is air. Knowing the conditions of heat exchange between the cooling air and the high-temperature aluminum billet makes it possible to obtain the ingot’s necessary physical and mechanical properties. The article describes the developed mathematical model of conjugate heat transfer during homogenization annealing of aluminum ingot. It allows analytically calculating the temperature of the ingots depending on the cooling time. To verify the data obtained by the mathematical model, the conjugate heat transfer in the ANSYS program was simulated.
Calculation Method of Working Rotational Angle of Automobile Transmission System and Its Applications
Authors: Li Yongzhuo , Lang Chunyan , Tian Zilong , Chen Zhiyuan 
Published: November 2021

Abstract
The working state and operating parameters of the automobile transmission system play a key role in the vehicle noise and vibration performance. Based on the basic calculation method of relative rotational angle, this paper proposes two methods for calculating the working rotational angle and torsional stiffness of the transmission system, which can effectively obtain the key information of the transmission system under the vehicle operating state. The working rotational angle, whose initial angle should be corrected by the average angle in the neutral gear coasting condition, can reflect the actual working state of the torsional vibration damper effectively. And the accuracy of the linear torsional stiffness obtained will be above 90%. Both simulation and experimental analysis results show that these two proposed application methods have high calculation accuracies and engineering feasibility.
Design and Application of Spiral Wound Gasket Sealing for Big Opening Flange for High Temperature and Pressure Vessel
Authors: Zhai Lihong , Li Xun 
Published: November 2021

Abstract
Metallic spiral-wound gasket sealing are generally applicable for the service conditions, which are subject to the periodic temperature and pressure changes, shocks or vibrations. The nominal size of the largest spiral wound gasket of flanges is according to the provisions of HG/T 20631; those more than this specification are in the scope of non-standard parts, which require customization and manufacturing. This paper aims for introducing the successful experience of the first application of customized for non-standard spiral-wound gasket sealing of the large opening flange used for pressure vessel which bears high temperature and high pressure. The paper demonstrated the basic principle and critical points for the design and application of customized non-standard spiral-wound gasket sealing for the large opening flange and provided the valuable reference of actual application experience for the design and manufacturing of similar components. This paper presents the experiences summary in the study field and provides valuable reference of actual application experience for the design and manufacturing of similar components.
Research Progress of Springback in Multi-Point Forming of Sheet Metal
Authors: Li Xinqi , Hu Shicheng 
Published: November 2021

Abstract
In the manufacturing of sheet metal, multi-point forming replaces the traditional integral die with discrete basic body groups to adjust the height of each basic body and form the required three-dimensional curved surface, thereby facilitating flexible processing. Multi-point forming is the most common approaches for the manufacturing of sheet metal but can cause serious shape distortion due to springback phenomena. In this paper, key research on springback is categorized and analyzed from three aspects: springback theory, springback numerical simulation analysis, and springback control, followed by summary of the current research status and outlook on promising future research directions of springback in multi-point forming springback. And the conclusion is drawn: in the future, multi-point forming of sheet metal using high-frequency ultrasonic excitation for springback control during the forming process coupled with artificial intelligence for springback compensation control will be a promising research direction for controlling springback in the multi-point forming of sheet metal.
Study on Bearing Mechanism of Split Grouting Pile Based on Finite Element Simulation
Authors: Wang Jinman , Li Shaofei , Zhou Mingru , Zhong Lin , Chen Yiming 
Published: November 2021

Abstract
In order to realize the directional and controllable splitting of splitting grouting, the field grouting test was carried out. Using a new grouting pipe designed, the splitting direction and size of the branch vein are effectively controlled through the control of grouting pressure and grouting amount. In order to explore the bearing characteristics of split grouting pile and provide necessary parameters for the design of split grouting pile composite foundation in engineering practice, the field static load test and indoor geotechnical test of split grouting pile are designed, and the ultimate bearing capacity of single pile and necessary soil parameters are obtained. In order to make up for the limitations of field static load test, the three-dimensional finite element model of pile, soil and branch vein of split grouting pile is established by using the finite element analysis software ABAQUS. The finite element analysis results are compared with the measured values of field test, and the variation laws of pile shaft axial force, stress and displacement of branch vein at different depths, pile side friction, etc. are further explored, Through these changes, the interaction and load transfer mechanism between pile and soil are analyzed, which provides a reference for optimal design.
A Review of Dynamic-Tribological Simulation Methods for Sliding Bearings in Internal Combustion Engines
Authors: Tong Dehui , Diao Ziyu , Sun Nannan , Du Xiangning , Zhang Yanyan , Liu Zhentao 
Published: November 2021

Abstract
The problem of friction reduction and wear resistance of sliding bearings is one of the key factors in determining the overall performance of internal combustion engines. This paper investigated and summarized the theoretical and simulation models of multi-body dynamics of crankshaft system, tribology of sliding bearings, and the wear calculation methods of the shaft-bearing friction pairs. Existing studies show that the dynamics model, hybrid lubrication model, and the friction and wear models request to be upgraded by comprehensively considering the material, structure, manufacturing process, working conditions, and etc. Based on the research status and existing problems of the above analyses, this paper summarizes the simulation models applicable to the field of dynamics and tribology of sliding bearings and presents the prospects for optimization of wear calculation methods for sliding bearings.
Design and Implementation of a High Precision Stewart Platform for a Space Camera
Authors: Liang Fengchao , Tan Shuang , Fan Jiankai , Lin Zhe , Kang Xiaojun 
Published: November 2021

Abstract
In order to design and implement a high-precision Stewart platform to precisely adjust the position and posture of the secondary mirror of a space camera, the following measures were taken: firstly, the inverse mathematical model and ADAMS parametric model of the Stewart platform are established, which are the basis of structural optimization design; secondly, the structural parameters of Stewart platform are obtained through structure optimization design in ADAMS after determining the objective function; thirdly, a 50nm resolution driving strut based on brushless DC motor, ball screw, grating ruler and PI closed-loop control law is designed, which strongly guaranteed the six degrees’ resolution of the Stewart platform that mainly consist of 6 such high-resolution driving struts; finally, the accuracy of Stewart platform is tested via dual frequency laser interferometer and photoelectric autocollimator, and the test results show that the displacement resolution of the Stewart platform is 0.2 μ m, and the angular resolution is 1”, which meets the requirements of the index. The Stewart platform has been successfully applied to the space camera by tuning the secondary mirror precisely in 6 degrees of freedom in the optical alignment experiment, which lays a solid theoretical and practical foundation for on orbit application in future.
Research on High Precision Rapid Online Measurement System of Crankshaft Based on Multi-station
Authors: Gu Tingting , Qian Xiaoming , Lou Peihuang 
Published: November 2021

Abstract
According to the structural characteristics and production requirements of the crankshaft, the online measurement platform of crankshaft was built. The multi-station assembly line is developed to measure, to mark and to classify the parameters and measurement elements of the crankshaft. In addition, SPC software is designed to perform mathematical statistics and analysis on the measurement information. It can distinguish between normal fluctuations and abnormal fluctuations in the production process, can inform the fluctuation state to determine whether it should be adjusted, can compare the fluctuations and provide direction for improvement. Finally, through multiple measurement experiments, the feasibility and effectiveness of the synchronous measurement scheme and data processing method proposed in this paper are verified. The experimental results show that GR&R is less than 9.3%, and measurement accuracy is less than or equal to 1μm.
Numerical Simulation and Experimental Study on Rotary Cold Extrusion Forming of Screw Rod
Authors: Li Peiai , Wang Baoyu , Wang Jiapeng 
Published: November 2021

Abstract
The rotary cold extrusion forming process is a plastic forming process with very low material loss, especially in the production of hollow screw rods with equal wall thickness. In this work, the rotary cold extrusion forming process of a hollow T2 copper screw rod with a wall thickness of 4 mm and solid T2 copper screw rod was verified by experimental method. The finite element simulation software Deform-3D was also used to simulate the rotary cold extrusion forming process of the screw rod. The effects of the die with different heights of the working belt and the different wall thickness of the billet on the eccentricity, extrusion force, and forming torque in the forming process of the screw rod were studied. The results show that it is feasible to process hollow and solid T2 copper screw rods with equal wall thickness by rotary cold extrusion. With the increase of die working belt height, the eccentricity of the screw rod becomes smaller and closer to the ideal eccentricity. With the increase of the wall thickness of the billet, the amplitude fluctuation range of the eccentricity of the screw rod gradually decreases. The higher the height of the die working belt, the greater the extrusion force and torque required in the extrusion process, and the more intense the change of torque. These results also provide theoretical guidance for the production practice and lightweight transformation of the screw pump rotor.
Mathematical Principle Analysis of Separation Point Prediction
Authors: Yue Peng , Zhang Jinghui , Peng Dewei , Wei Sibei 
Published: November 2021

AbstractDuring the development of fluid mechanics, fluid separation is an important issue. So far, there is no mathematical formula to reveal and describe the essence of fluid separation. At the same time, due to the high cost and limitation of the experimental method, another method is urgently needed to predict the separation position of the fluid. After axiomatizing fluid mechanics and combining the principle of excited state of quantum mechanics, this paper reveals that fluid separation is a special form of fluid in an excited state, and deduces the state conditions of fluid separation. The research results of this paper provide new ideas for solving problems in fluid separation and engineering applications.