bluuebunny/crossref_metadata_2025_split huggingface dataset:
A numerical Investigation on Schardin’s Problem Using a Quasi-DNS Solver
Authors: Li Weixuan , Li Yingkun , Li Chunlei , Zhu Liang , Chen Xiong 
Published: May 2022

Abstract
In the present research, Schardin’s problem is numerically investigated using a FORTRAN based quasi-DNS solver, the numerical results are validated using the experimental result and the shock impinges process is analyzed in detail. During the shock impinges process, we noticed that the periodical vortex shedding phenomena could be observed, thus, the proper orthogonal decomposition (POD) is utilized to shed light on the flow features during the vortex shedding process.
Construction of an Smart Progress Production Unit Based on Paddle Boring
Authors: Guan Xiang , Sun Jinhao , Hou Zhixia , Xiao Qingdong , Chen Long , Gan Lu 
Published: May 2022

Abstract
With the continuous improvement of hardware product performance and data processing capability and the rapid development of network communication technology, the intelligent technology of computer systems is becoming more and more mature, and the intelligence of manufacturing has become the focus of people's attention. The intelligent performance of manufacturing is to use the knowledge obtained from data analysis to make inferences and decisions to solve problems, and the Cyber-Physical System (CPS) supports the deep integration of informationization and industrialization by integrating advanced information technology and automatic control technology, such as perception, computation, communication, control, etc. Although there has been great progress in the research of CPS, it has been widely used in the development of computer systems. Despite significant progress in CPS research, some key issues have yet to be fully addressed at the shop floor level, including dynamic reorganization and local intelligence. These issues have hindered the research on the intelligence of complex processes. For progress units of complex processes, this study proposes a CPS-based smart progress unit (SPU) construction method. In order to improve machining efficiency and quality consistency, this study proposes a multi-source data acquisition technique and a multi-objective optimization algorithm to process the data within the machining unit. Finally, this study takes the paddle boring process as an example, and designs hardware and software systems to automate the paddle boring process and meet the needs of automation and intelligent transformation of the paddle boring process.
Design of X-axis Feed System of Cradle Five Axis CNC Machine Tool and its Computer Finite Element Analysis
Authors: Zhu Xiurong 
Published: May 2022

Abstract
For the design of the x-axis feed system of the cradle five axis CNC machine tool, the entity modeling is carried out by using CATIA P3 v5r21 and Auto CAD; the x-axis design of the cradle five axis CNC machine tool is carried out and the accuracy and strength are checked; the CAE analysis of the structural strength and stability is carried out by using the general structural analysis module. The DMU kinematics module is used to eliminate the interference. Optimize the structural parameters to improve the stability and accuracy of machine tools.
Dynamic simulation of flap mechanism considering assembly error
Authors: Xue Xiaofeng , He Zhiyu , Feng Yunwen , Cui Weijun 
Published: May 2022

Abstract
The existence of assembly error will have an impact on the kinematic accuracy and dynamic performance of mechanical system, which can not be ignored. Therefore, a dynamic simulation method of flap mechanism considering assembly error is established. Firstly, the motion digital prototype of flap mechanism and the rigid flexible coupling dynamic model considering the deformation of flap wing surface are established, and then when the error direction is fixed, by setting the deviation values of the two driving shafts, the influence on the driving torque of the flap mechanism and the load of key components under the working conditions of 2mm, 4mm and 6mm is explored. Then, through the eight error directions defined by the deviation function, the influence of the direction error of the drive shaft assembly on the driving torque of the flap mechanism is obtained when the error size is 6mm fixed. The results show that when the assembly deviation of the two driving shafts is in the three working conditions with the selected size, the flap trajectory basically coincides, and the driving torque of the inner mechanism increases by 10.19% when the error is 6 mm; When the size of the assembly error remains fixed, the change of the error direction will increase the driving torque of the flap mechanism. The dynamic simulation study can provide some theoretical guidance for the manufacturing and assembly of this type of high-lift device.
Optimal Design and Research on the Structure of Tripod Constant Velocity Universal Joint
Authors: Lu Yujun , Wang Wei , Feng Chanjing , Zhao Zhichang 
Published: May 2022

Abstract
In order to reduce the problems of wear between the internal structures of the universal joints and short service life, a new track contact structure was designed based on the original type of universal joint structure, and a mechanical model of the structure was established. In the ANSYS Workbench, the material properties, contact pair settings, universal joint force and other parameters are analyzed, the contact stress changes between the original structure and the optimized structure are studied, and the torsional fatigue life experiment is carried out in conjunction with the experimental workbench. The results show that the optimized new structure can effectively reduce wear and increase durability in the service process, thus extending its service life.
Evaluation of flow and heat transfer performance of spiral coil jacket with different cross sections
Authors: Wang Lv , Liao Xiaoping , Li Hongjun 
Published: May 2022

Abstract
The flow and heat transfer performance of the spiral coil jacket for a reactor with five different cross-section shapes was evaluated. The comprehensive performance of five jacket models was analyzed through PEC and JF evaluation factors, which provided a basis for jacket design in industrial application. The results showed that at certain Reynolds number, the Nusselt number of the arcuate cross-section jacket was lower than that of the half-pipe jacket, but the flow resistance coefficient was lower and the resistance loss was smaller. The secondary flow generated by the half pipe jacket made the temperature gradient in the corner of the cross section far less than that of the center, thus affecting the heat transfer of the jacket. The vortex structure analysis showed that the edges and corners of the inner wall of the jacket were prone to generate vortex structure. The comprehensive evaluation factors of PEC and JF showed that the arcuate jacket of 140° had the best comprehensive performance.
Numerical Investigation on Aerodynamic and Electromagnetic Influence of Shape of The Grilles in a Rectangular Duct
Authors: Wang Xufei , Yang Qingzhen , He Yubo , Zhang Saile 
Published: May 2022

Abstract
The electromagnetic scattering characteristics of the inlet with grilles are calculated to verify the feasibility to reduce the radar cross section by installation of grilles. The Method of Moment (MOM) is used to calculate the models. According to its complicated structures, the inlet with grilles is simplified and the structured mesh is applied to specify the minor features of a large quantity of grilles to obtain aerodynamic characteristics of these models. The SST k-ω turbulence model based on the RANS method is utilized to simulate the air flow through the inlet. A clear duct with the geometric parameters (180mm 180mm 400mm) as well as the duct with grilles involving different parameters (shapes, thickness) is applied for the numerical simulation at the speed of 0.6 Mach at a certain range of angles of attack. Grilles in different parameters are simulated separately and compared with the clear inlet and the inlet with grilles, to find an approximate but simple method to estimate the aerodynamic influence taken by the different grilles. The results implicate that grille installation in the inlet has a significant positive influence on electromagnetic stealth performance. RCS drops by 4.80dBsm at an angle of attack of 0°. Meanwhile, substantial RCS reduction at range of angle of attack from 0°to 20° is found. Thickness and shape have remarkable influence on aerodynamic performance instead of electromagnetic scattering characteristics (f=1GHz, VV). The couple of grilles and inlet duct shows a little effect on aerodynamic characteristics compared with the single-element grille. It is acceptable to simulate grilles with inlet by numerically calculating the single-element grille.
Design of 2×250kN large-span hoist hydraulic automatic grabbing beam
Authors: Cheng Tanghua , Ren Tao , Chai Xu , Yao Kun , Jia Jiangming 
Published: May 2022

Abstract
In water conservancy projects, automatic grabbing beams, as an important supporting equipment of mobile hoisting equipment, are widely used to improve the performance of operating gates and trash racks. This paper takes the hydraulic automatic grabbing beam of the 2 × 250kN large-span hoist at Baihetan Hydropower Station as an example. The design of the hydraulic automatic grabbing beam for the hoist is systematically analyzed, combined with engineering examples, and the most unfavorable conditions are used. As a result of the calculation, some design parameters of the long-span grab beam were obtained. The test results show that all performance indicators can meet the design requirements and relevant standard requirements.
Energy consumption and mechanical proprietaries of Hybrid Deposition & Micro-Rolling
Authors: Huang Cheng , Zhang Haiou , Wang Guilan 
Published: May 2022

Abstract
The traditional forging process involves high energy consumption due to the giant equipment, long process, and low material utilization. Recently, metal additive manufacturing technology has developed rapidly with the advantage of high utilization. However, looseness and defects caused by the anisotropy of layer forming would result in low mechanical properties and fatigue properties. The hybrid deposition and micro rolling (HDMR) combined in-situ rolling with additive manufacturing, which applies a forging force to the built part by a micro-roller. A comparison is carried out with the conventional forging approach in terms of energy consumption and mechanical properties. It was found that components of Ti-6Al-4V made by HDMR showed a better strength performance in tensile strength and impact toughness with lower energy consumption than the traditional forging approach. Additionally, HDMR realizes integrated manufacture instead of the distributed manufacturing of large-scale equipment in a lengthy process, which is a promising substitute for conventional forging.
Microstructure and Mechanical Properties of C10100 Copper/304 Stainless Steel Electron Beam Welded Joint
Authors: Sun Wenjun , Wang Shanlin , Hong Min 
Published: May 2022

Abstract
Copper-steel dissimilar welded structural components are widely used in heat exchangers of nuclear power equipment. Electron beam welded dissimilar joints of C10100 copper/304 stainless steel sheets were investigated in this research. The experimental results for the microstructure and mechanical properties proved that optimizing welding process parameters could be used to get a well-formed weld without defects and the microstructure of weld was consisted of a mixture of two finite solid solutions in austenite matrix. The grain orientation was random, with dominating high-angle grain boundaries. The microhardness dropped along the 304SS / weld/C10100 copper interfaces, and the tensile strength reached 310 MPa. The heat-affected zone on the C10100 copper side appeared as the weakest part due to the largest austenite size and the least number of high-angle grain boundaries.
Feedforward Model-Based Intelligent Compensation System for Spindle Dynamic Thermal Error
Authors: Tang Jiangwen , Jiang Li , Xue Liang , Yang Zhuang 
Published: May 2022

Abstract
Among spindle dynamic errors, thermal error is an important factor affecting machining precision, the most convenient and economical solution for which is dynamic compensation of thermal error. In view of defects of complicated system, complex debugging, poor stability, high cost, etc., in the existing compensation approaches, thermal error compensation technology is investigated with compensation model established to complete the system design. The system is tested on the spindle of precise horizontal machining center. In the experiment, multiple linear regression, BP neural network, etc. are taken for technical analysis with dynamic feedforward model established. The experimental results indicate that the compensation system under study has dynamic compensation rate of over 90%, while the spindle has greatly shorter warm-up time, which can operate normally before entering the thermal steady state. The finally completed feedforward model-based intelligent compensation control system has good steady-state and dynamic compensation performance. In particular, its self-correction function greatly improves system adaptability and simplifies operation in use.
Three-dimensional cooperative guidance law for multiple missile based on sliding mode control
Authors: Zheng Zhongxu , Jiang Zhenyu , Sun XiaoDong , Fan XiaoShuai , Ma Rundong 
Published: May 2022

Abstract
Based on the missile-target three-dimensional relative motion model, a multi-missile coordinated three-dimensional guidance law with attack time constraints is designed for attacking stationary targets. The sliding mode variable structure control is adopted in the pitch channel, and the dynamic inverse control is adopted in the yaw channel. By maneuvering in the yaw channel, adjusting the missile's attack time and comparing with the results of using augmented proportional guidance, the simulation results show that the algorithm designed in this article can achieve coordinated attack and high hitting accuracy, which verifies the correctness and superiority of the algorithm.
Design of High Precision Semiconductor Laser System
Authors: Zhou Mengyuan , Wang Gaojie 
Published: May 2022

Abstract
In PCR technology, the suitability and stability of the light source used to excite fluorescence is particularly important. Semiconductor laser not only plays an important role in medical, science and technology, aerospace, transportation, communications and other fields, but also brings great changes to society. In this paper, the research background and the overall design architecture of the laser are described first, and then the circuit design of the key modules of the system is described in detail, the optical control closed-loop feedback system ensures the stability of laser drive current, and the temperature control closed-loop and PID algorithm reduce the adverse effects of temperature on laser power. At the same time, the sparrow search algorithm is used to optimize the three parameters of PID, the simulation results and test data show that: The whole design fully meets the needs of the application scene.
Energy Estimation and Testing Verification on Ignition of a Torch Ignition System
Authors: Xu Jiabao , Zhuo Danchen , Xing Lixiang , Gao Yushan , Jin Ping 
Published: May 2022

Abstract
The torch type electric ignition system is a desirable choice for reusable liquid vehicle engine. It is generally believed that the ignition and start-up process of engine are crucial and high-risk. However, due to the complexity of combustion experiments, the ignition and start-up process can be efficiently analysed from the perspective of energy exchange. By building the energy analysis equations of electric spark plug, ignition chamber and thrust chamber, the energy estimation method of torch type electric ignition system is established. Furthermore, the time scheduling and examining method for multi-injector ignition and start-up process of large flow liquid rocket engine with multi-injector are established. The hot-firing test of LOX/CH4 rocket engine is carried out according to the design parameters to validate the effectiveness of the energy estimation method.
Design and verification of small solid rockets navigation algorithm test platform
Authors: Fan Xiaoshuai , Bai Xibin , Jiang Zhenyu , Zhang Shifeng , Zheng Zhongxu 
Published: May 2022

Abstract
Aiming at the navigation system of small solid rockets, a navigation algorithm test platform with real time simulator and flight control computer is designed. The inertial navigation algorithm is taken as an example to test the effectiveness of the platform. The flight dynamic model of a small solid rocket is established in a real time simulator, and the test is carried out in the working environment of a small test rocket to simplify the model. The acceleration and angular velocity data generated by the simulation is sent to the onboard computer to calculate the attitude of the rocket in real time, which verifies the correctness of the data communication link, real time solution and navigation algorithm between the onboard computer and the real time simulator. The test results show that the test platform is easy to use and can test the rocket navigation algorithm quickly and effectively.
Aircraft/Engine Integrated Design for an Air-superiority Unmanned Aerial Vehicle
Authors: Jianzhi DENG , Wenyan SONG , Guangjun YANG , Feng JIANG , Neng XIONG 
Published: May 2022

Abstract
Aiming at the demand of efficient energy management for wide flight envelope of air-superiority unmanned aerial vehicle (UAV), an conceptual and preliminary design of air-superiority UAV with oil-electric hybrid power was proposed based on the idea of integrated aircraft and engine modelling. The evaluation model of the UAV aerodynamic performance and the thrust requirements of full flight envelope were determined, then the matching configuration of target turbofan engine was proposed. According to general design parameters of UAV, the simulation model and constraint relations for aircraft-engine integration performance calculation were established, parameters were optimized for typical multi-mission conditions, the tactical performance of future advanced air superiority UAV was predicted. The integrated design method of air superiority UAV upon hybrid electric turbofan can also be applied to improve the performance of UAVs in service, which established in this paper has good engineering practical value.
Modeling Investigation of Liquid Oxygen Flashing Spray with CFD
Authors: Luo Meng , Zhu Pingping , Rana Usman , Ma Hu , Yu Zhendong , Haidn Oskar J. 
Published: May 2022

Abstract
Injection of cryogenic propellants (e.g. liquid oxygen) into low-pressure environment (e.g. upper-stage rocket engine) may trigger flashing phenomenon, which severely affects the propellants’ mixing and combustion. In order to unveil the characteristics of flashing sprays, numerical models of flashing sprays were developed and validated. First, a developed model based on Adachi-correlation was employed for the flashing spray simulation. The results show good agreements with the experiments, both for the flashing spray morphology and temperature distribution. In the near-injector region, the flashing evaporation dominates the spray vaporization with the evaporation mass flow rate of about 2 orders of magnitude higher than that by the other heat transfers, whereas downstream the injector, the external heat transfer (i.e. heat conduction and convection) does. Furthermore, a new flashing spray model based on the nucleate boiling theory was proposed, which shows an improved agreement of the droplet temperature between the simulation and test data.
Experimental research on weathercock interference characteristics of weathercock airspeed tube
Authors: Chengchuan Yang , Zheng Gong , Yongliang Chen , Wei Zhong , Yalei Bai 
Published: May 2022

Abstract
Pitot tube is one of the most important airborne devices on the aircraft. The airspeed tube can not only provide the pilot with the airspeed of the aircraft, but also the rate of climb of the aircraft. In this paper, the wind tunnel test method is used to test the weathercock type airspeed tube used on a domestic supersonic tailless layout aircraft and it obtains the airspeed tube's angle of attack and sideslip angle weathercock interference characteristics and total static pressure aerodynamic characteristics. In this process, we find that the sideslip angle begins to offset with the angle of attack increasing and the offset is about -1° when the airspeed exceeds 1.5 Ma. Subsequently, CFD calculations are used to compare and supplement the wind vane characteristics obtained from the wind tunnel test. It is found that the pressure data collected by the airspeed tube has a certain error due to the interference characteristics of the wind vane. Finally, the pressure error is corrected by BP neural network prediction model. It provides a reference to calibrating air-data-sensors for researchers.
Aerodynamic of a probe using an inflatable braking device during its descent in mars atmosphere
Authors: Koryanov Vsevolod V. , Menetrier–Hacquemand Nathan 
Published: May 2022

Abstract
For reentry in Mars atmosphere, inflatable braking devices are interesting as they do not use rigid heat shields, parachutes, or retrorockets which limits the mass to send into space. This paper focuses on one MetNet probe, to validate the use of inflatable braking device geometry. This study shows the results on aerodynamic coefficients determined using different solvers from OpenFOAM software in distinct configurations exposing that small deformations of the braking device in the stages of the probe’s reentry should not threatens the mission. Finally, this study shows final velocity determined using a Python program and compared with expected values on different locations on Mars’s surface to ensure that the probe survives its descent.
Gas-Solid Interface Interactions Based on Molecular Dynamics Simulations
Authors: Zongyang Li , Lin Bi , Jianqiang Chen 
Published: May 2022

Abstract
Gas-solid interface interaction as the key point and difficult point of dilute gas flow, understanding the mechanism of it, to have a clearer understanding of the gas molecules in the solid near-wall surface motion law. This paper combines the molecular dynamics method and particle beam method to simulate the interaction between argon molecules and solid platinum wall surface, to study the scattering law after the collision between gas molecules and solid surface at different incidence angles and the mechanism of energy conversion between them, the results show that the tangential kinetic energy is lost after the collision between gas molecules and wall surface, while the change of normal kinetic energy is determined by the magnitude of the incident velocity; the incident velocity is small, the reflected tangential velocity distribution basically fits the Maxwell reflection distribution when the incident velocity reaches a high speed, and the reflected tangential velocity distribution appears head-and-shoulder or even bimodal distribution, which is helpful for future research on the tangential momentum adaptation coefficient of the scattering nucleus model.