bluuebunny/crossref_metadata_2025_split huggingface dataset:
DC negative corona discharge characteristics of the needle-plate electrode under different air pressures
Authors: Lv Duo , Zhou Yang , Liu Jiqiu , Li Feng , He Wangling , Wang Yanzhao , Wan Baoquan , Gan Zheyuan , Wei Hongyu 
Published: August 2023

Abstract
Because of the low normal atmospheric pressure and frequent, more severe corona discharges in high-altitude regions. The electromagnetic environment problems caused by the corona discharge restrict the line design in high-altitude areas. The variance in the law of negative DC corona characteristics under different air pressure conditions is derived using an artificial climate tank with adjustable air pressure. The characteristics of the negative DC needle-plate corona discharge were measured experimentally. The negative DC corona discharge pulses at 89.4 kPa–56.04 kPa were obtained, and the characteristics of the current pulses were statistically examined. The study of the mechanism of the DC corona discharge can benefit from the research findings as essential reference data.
Sinusoidal Frequency Estimator by Using Interpolation of Four DTFT Spectral Lines
Authors: Bai Yuchan , Liu Jinyu , Wu Huihao , Fan Lei , Li Renqing , Xing Jun 
Published: August 2023

Abstract
This paper proposes a sinusoid frequency estimator by interpolating four Discrete Time Fourier Transform (DTFT) samples. Firstly, Discrete Fourier Transform (DFT) is performed on the received sinusoid. Then we find the positional information of the maximal DFT bin and obtain the coarse estimation results. Next, the proposed method uses four symmetrical DTFT samples on both sides of the maximal DFT bin to interpolate the signal frequency and obtain accurate estimation results. Simulation experiment results illustrate that the proposed method’s accuracy is higher than that of the competitive methods. When the signal-to-noise ratio (SNR) increases from 0dB to 90dB, the presented estimator performs better than the competitive methods.
Voltage Regulating Strategy of a New LCC/S+L Inductive Power Transfer System
Authors: Liao Hongbin , Wang Wei , Zhang Weige , Du Xiaogong , Yu Qingsong , Wang Lifeng 
Published: August 2023

Abstract
In the voltage control of the inductive power transfer (IPT) system, a cascaded DC-DC converter is normally adopted which reduces the power density. However, the wireless communication between the transmitter and the receiver may lead to a delay of control as well as communication instability. This paper proposes a new LCC/S+L resonance topology for the IPT system, which can realize single-stage voltage regulation on the receiving side with both buck and boost capability. Based on the fundamental wave analysis method, this paper analyzes the working principle of LCC/S+L resonant topology. Then the control strategy of the phase shift angle between bridges and within bridges is obtained by the voltage of both ends of the series inductor and the load voltage vector. It is verified by simulation that the proposed new resonance topology and control strategy can achieve output voltage regulation of 300-500 V with a constant 375 V input DC voltage.
Short-circuit Fault Detection in Low-voltage DC Microgrids Based on Improved Current Change Rate
Authors: Huiyin Cai , Zhenyu Li 
Published: August 2023

Abstract
Along with the explosion of new energy sources, DC microgrid has obvious advantages as well as better development paths, but reliable fault detection is still one of the key issues to be solved for DC microgrid. The fault current characteristics are analyzed by a fault RLC equivalent circuit, and the characteristics at different fault location points are further analyzed on the independent DC microgrid model composed of a PV generation unit, an energy storage unit, and a load unit. A fault detection method based on the improved current change rate is proposed by combining the current abrupt change direction. A DC microgrid model with a bus voltage of 400 V is built and simulated in Matlab/Simulink. The simulation results show that the proposed method can detect and isolate bus and unit short-circuit faults in less than 2 ms, ensuring the proper operation of the whole system, which has a certain reference significance for fault protection of low-voltage DC microgrids at independent operation sites.
Estimation of Electricity Supply and Demand under Dual Carbon Goals: A Chance-constrained Linear Programming Model
Authors: Yang Xuan , Zhou Ruoxin , Tang Fei , Yan Zhouzhou , Wei Xiaoqing 
Published: August 2023

Abstract
Implementing the green and low-carbon development strategy has become a global consensus with the increased severity of global environmental problems. In 2020, Chinese President Xi Jinping put forward China’s carbon peak and carbon neutrality goals (i.e., dual carbon goals), which is a guideline for the development of Chinese power systems. Thus, a supply and demand estimation system that includes dual carbon indicators and considers the long-term supply capacity is needed. To address these gaps, this study put forward an estimation model and provided the solutions. First, a supply and demand estimation indicator system is established to meet the dual carbon goals. Second, with minimizing cost being the main objective and several constraints, a chance-constrained linear programming model is used to estimate the supply and demand of electricity in 2030, 2040, and 2050. Finally, with model relaxation, we obtained the estimation results with Matlab-Cplex, which verified the efficiency and validity of the proposed model.
Evaluation of the Influence of Thermal State and Mechanical State of Overhead Conductors on Power Flow
Authors: Sun Rongfu , Wang Jingran , Ding Ran , Geng Yan , Qiu Wei , Pei Yuting , Zhao Leiqing , Yao Yiming 
Published: August 2023

Abstract
Overhead conductors’ thermal and mechanical states are the critical factors to determine their safe operation and have an impact on the power flow calculation. The thermal and mechanical state parameters of overhead conductors change the resistance parameters of the line on the one hand and change the line parameters through the tensile action of force on the line on the other hand. The parameters of the line are closely related to the power flow calculation of the power system. Based on two kinds of influence mechanisms and regional power systems, this paper quantitatively analyzes the influence of thermal state and mechanical state on power flow under light load and heavy load.
The Improved Control Method of Parallel Microgrid Inverters
Authors: Wang Liwei , Miao Hong 
Published: August 2023

Abstract
The parallel of inverters is inevitable in the operation of distributed generation with a Microgrid. However, due to the difference in line impedance between each parallel inverter and the public AC bus in the microgrid, the m available control method is insufficient to overcome the disadvantages such as unbalancing distribution of power, large circulating current, and poor dynamic characteristics, etc., especially when the line impedance difference is large. To conquer the above problems, the paper proposed an improved droop control strategy, in which a differential module is adapted to the droop control to improve the dynamic response. Further, a modified adaptive virtual resistance is proposed, so that the system can maintain high response speed, high stability, and robustness. These can effectively benefit power sharing and circulation suppression of parallel inverters while ensuring excellent dynamic characteristics of the system. Finally, the effectiveness of the improved control method is verified by the simulation results.
Online parameter identification of permanent magnet synchronous motor based on recursive least squares algorithm
Authors: Lv Sixun 
Published: August 2023

Abstract
In order to solve the problem of variable parameters in the system when the PMSM works, this project intends to use the recursive algorithm in the steady state of alpha-beta. This project identifies the two parameters as the fixed values of two parameters at the same time, so as to reduce the number of parameters to be estimated and avoid the problem of under-classification. The proposed method is studied experimentally on the 2 kW PMSM experimental platform. Simulation results show that this method can quickly and accurately realize the online identification of parameters in the PMSM system.
Thrust Pointing Adjustment of Electric Propulsion System
Authors: Li Zongliang , Zhao Jingchao , Peng Zheng , Song Fei , Li Zhong , Liu Yizhuo 
Published: August 2023

Abstract
The satellite uses an electric propulsion system (EPS) to complete the north-south station-keeping (NSSK) work. Due to the change of satellite centroid position during the whole life period, electric propulsion thrust pointing adjustment is required to minimize the deviation between the thrust vector and the satellite centroid, to avoid the additional interference torque and the decrease of the position protection efficiency of the EPS. In this paper, the electric propulsion thrust pointing adjustment method is designed, the mathematical model of the pointing adjustment angle is established, the conformity of the thrust pointing adjustment during the whole life of the spacecraft is analyzed, and the ground integration test verification and the on-orbit electric propulsion thrust pointing adjustment verification are completed. The analysis and verification data show that the adjustment range and accuracy of the EPS can meet the requirements of the NSSK mission.
Aeroacoustics Analysis of Propeller Blades
Authors: Zhang Yifei , Zhao Longzhi , Zhao Tianming , Liu Lu , Xu Lijun 
Published: August 2023

Abstract
Under rapid development, drone propellers are facing two essential problems: noise emission and aerodynamic efficiency. In this work, the aeroacoustics characteristics of two propellers were experimentally and numerically investigated. Both propellers have exactly the same design points, and MTprop-1678 has a thinner blade and larger chord than MTprop-1688. Results showed that the broadband noise of 1678 significantly rose due to a larger Reynolds number, and the total noise was larger. The study shows that reducing the Reynolds number might be a good idea for propellers’ noise reduction.
Analysis of Interaction between Leakage Flow and Upstream Wake by Proper Orthogonal Decomposition Applied
Authors: Qiao Tianyang , Yang Ce , Hu Chenxing 
Published: August 2023

Abstract
The turbine blade generally works in severe aerodynamic environments such as high temperature and high pressure. Various forms of secondary flow, unsteady potential flow, periodic wake in the blade passage, and strong interactions among these flow structures affect the efficiency of the turbine seriously. This paper performs a numerical simulation of the T106 cascade to investigate the flow characteristics and performance under the interaction between upstream wake and leakage flow. The cascade flow with and without upstream wake are decomposed by proper orthogonal decomposition, and the mode characteristics of leakage flow and wake are obtained. The results indicate that periodic wake can significantly reduce the energy loss in the channel and tip leakage flow has a greater impact in the region near the shroud plane. According to the proper orthogonal decomposition, the second to seventh modes account for 96.14% of the total energy except for the time-averaged mode. The second mode is identified as the wake mode and leakage flow can significantly increase vorticity in the tip region. The harmonics of the wake mode are greatly affected by leakage flow, especially at the trailing edge region.
Influence of Spatial Characteristic Parameters of Film Cooling Holes on the Strength of Turbine Blade
Authors: Li Shifeng , Yang Baocheng , Ye Wenming 
Published: August 2023

Abstract
In order to improve the fatigue resistance of turbine blades with special-shaped film cooling holes in real working environments, the spatial geometric characteristics of the gas film holes are studied by using the numerical calculation method of gas-thermal-solid depth coupling, which is based on the spatial geometric characteristics of special-shaped film cooling holes. Then, the influence of stress level and durable strength at the hole edge is developed, which includes the parameters of the film jet angle, the flow direction divergence angle, the span-wise divergence angle, and the pore diameter on the film cooling holes. The results show that the flow direction expansion angle and the spanwise expansion angle are the most significant impacts on the hole edge stress at the same pore diameter and film jet angle. Compared with the cylindrical gas film hole, it is decreased by about 9.3% to 25.8%, which is the hole edge equivalent stress of the special-shaped gas film hole. The durable strength of the hole edge increases by about 11.1% to 25.2%.
A space terahertz antenna fabricated by 3d printing technology
Authors: Wang Feng , Cheng Kewei 
Published: August 2023

Abstract
In this paper, a case of space high-precision THz antennas based on 3D printing technology in engineering has been proposed. The reflectors and the supporting structure have been printed in an integrated way by adopting the structural optimization design method suitable for the high-precision 3D printing process and using the honeycomb structure in the low-stress area. This can avoid the assembly error caused by the assembly of various components of the antenna and achieve the goal of integrated, high-precision, lightweight, and high-thermal stability 3D printing, and manufacturing, which provides an idea for high-precision manufacturing of 3D printing technology in space-borne THz devices.
Analysis and Optimization of Interior Medium and Low Frequency Noise of a Certain Vehicle under Constant Speed Driving Conditions
Authors: Li Zhao Wen 
Published: August 2023

Abstract
There is a large amount of medium and low frequency noise in the interior of a certain vehicle type under constant speed driving conditions. Through identifying the noise source, it is determined that it is mainly caused by road noise. The suspension rubber bushing, mounting inching stiffness, and vehicle body sheet metal are optimized, and the interior noise is reduced by 3 to 5 dB (A).
Propeller flow field simulation analysis and structure optimization of multi-rotor UAV
Authors: Lin Xuejie , Yan Rongjie 
Published: August 2023

Abstract
Propeller lift characteristics are the most important parameter affecting the performance of multi-rotor UAVs. In this paper, the propellers of three airfoils, RAF 6, CLARK Y, and E214, are modeled in three dimensions. The flow field simulation analysis of the three models is carried out using FLUENT. After the simulation, it is found that the lift of CLARK Y is about 1100 N, which is the best effect, but there are problems, such as excess lift. Therefore, the wing shape of CLARK Y is optimized, and the lift force is about 700 N after optimization, which can meet the practical application requirements. It can provide some reference to the practical engineering application of UAVs.
Numerical simulation of mechanical interaction between pellet and zircaloy-4 cladding under reactivity-initiated accident conditions
Authors: Zhou Yunfei , Xu Qian , Liu Bo , Hu Zhen 
Published: August 2023

Abstract
Reactivity-initiated accident (RIA) is one of the accidents considered by fuel safety criteria. The power pulse caused abrupt expansion of the pellet, leading to pellet and cladding mechanical interaction (PCMI). Cladding ductility is gradually decreased in the process of oxidation and hydrogen uptake during irradiation. As a result, the extrusion of the pellet to the cladding causes the cladding to produce greater hoop stress and hoop strain, which leads to damage. A simulation of PCMI using ABAQUS was designed to analyze cladding mechanic properties. By comparing the calculation results of the simulation scheme with the data obtained in the reactor experiment, it is proved that the simulation calculation results are in good agreement with the experimental data in the reactor, and the rationality of the simulation scheme is verified. Based on the out-pile mandrel equipment simulated PCMI, the corresponding finite element model was established to study related test parameters.
By analyzing the results of the simulation calculation outside the reactor, it is found that the pellet material, cladding temperature, compression rate, tensile load, friction coefficient and the cladding hoop stress and hoop strain have a certain relationship: (1) The choice of pellet material affects the reactor. The overall law of hoop stress-strain in the external simulation results basically has no effect. (2) The temperature of the cladding has effect on the hoop stress peak. (3) The compression rate has effect on the time for the cladding to reach the hoop peak stress. (4) Tensile load will affect the starting position of the hoop stress-strain of the cladding. (5) The friction coefficient has a significant influence on the stress and strain trend of the cladding. The outside experiment can be carried out more effectively, and it can provide guidance and a basis for the outside experiment.
Numerical Simulation of Plasma Igniter Efflux Characteristics Based on Multi-Physical Field Coupling
Authors: Meng Tianyu , Wu Xing , Zhang Xun , Lin Weibin 
Published: August 2023

Abstract
To explore the chamber plasma jet ignition effect, the establishment of pre-chamber plasma jet ignition based on a 3D model using the method of numerical simulation was carried out on the working process of the plasma ignition numerical calculation. The analysis of firearms in the combustion chamber ignition characteristics provided a reference for the ignition performance boost. The results show that the jet velocity at the igniter outlet can reach 78 m/s and the jet temperature can reach 2300 K, which makes the hot jet spread far enough in the reflux area and ensures that the jet can achieve the effect of heating and igniting in a larger area. The mixture in the air reacts with the kerosene position along the border, ignition in the igniter fine channel before export, igniter speeding up the export position of flow velocity, the jet core region of the temperature of 2400 K, the igniter export position of kerosene component concentration was 45%, the concentration of O2 was 20%, the H2O concentration was 15%, and the CO2 concentration was 7%. The ratio of air to kerosene should be such that the two flow at similar speeds in the mixing area.
Noise Reduction on a Low Reynolds Number Propeller
Authors: Zhao Tianming , Zhao Longzhi , Zhang Yifei , Liu Lu , Xu Lijun 
Published: August 2023

Abstract
With the mass application of drones in daily work, more attention has been paid to the noise problem. The noise generation mechanism of low Reynolds number propellers is studied in this paper. It is found that there are laminar separation bubbles on the suction surface, causing an increase in broadband noise. Leading edge boundary layer trips are added to remove the bubbles. Finally, experimental measurements indicate that isolated propeller noise reduction is up to 5 dBA. It still has a 1.5 dBA reduction in the full-loaded hovering drone test, which brings many conveniences for daily work.
A New Intelligent Recognition Method for Maneuver Modes of Re-entry Gliding Vehicle
Authors: He Yang Chao , Wang Ya Jun , Li Jiong , Li Ming Jie , Li Wan Li , Zhang Jin Lin 
Published: August 2023

Abstract
Aiming at the problem of maneuver mode recognition for re-entry gliding vehicles (RGV), this article proposes a new intelligent method for maneuver mode recognition of re-entry gliding vehicles. Based on the extracted feature parameters that fit the maneuver characteristics of the vehicle trajectory and the constructed RGV maneuver modes trajectory library, an LSTM deep learning neural network was built to train the extracted new feature parameters. Compared with other typical feature parameters in network training, the results show that our proposed feature parameters converge faster and more stably in LSTM maneuver mode recognition network training, and achieve high recognition accuracy.
The Stability of Longitudinal Motion of Amphibious Aircraft During Takeoff
Authors: Shi Sheng-zhe , Gao Xian-Jiao , Jiang Ting , Sang Teng-jiao 
Published: August 2023

Abstract
In this paper, the mathematical model of the takeoff of an amphibious aircraft was established. On this basis, the hydrodynamic coefficients in the pitch and heave motion equation were calculated using the strip theory. The stability criterion was used to analyze the longitudinal motion stability of the amphibious aircraft during takeoff, and three characteristic parameters of the general stability of longitudinal motion were obtained: natural period, half-decay period, and damping ratio. The result showed that the motion of amphibious aircraft was stable during takeoff.
Comparison of Different Turbulence Models in Numerical Calculation of Low-Speed Flow around NACA0012 Airfoil
Authors: Sun Zhaozheng , Yan Wenhui 
Published: August 2023

Abstract
To further develop a more effective turbulence model and improve the calculation accuracy of the flow, a new turbulence model was constructed using the deformation rate tensor, grouping the average. Due to the need to evaluate the applicability of the new turbulence model in the numerical calculation, the flow around the NACA0012 airfoil with a Mach number of 0.15 and multiple angles of attack was calculated on the OpenFOAM calculation platform based on grid independence research. The Spalart-Allmaras (S-A) model and the newly proposed turbulence model were adopted. The surface pressure and lift coefficients of the NACA0012 airfoil were calculated and compared with the experimental data. It was revealed that the two models simulated the flow around the airfoil well, and the S-A model was slightly better for calculating the airfoil pressure coefficient. The new turbulence model was more accurate for calculating the lift coefficient, thus illustrating the preliminary applicability of the new model to the low-speed flow around the airfoil.
The Optimization of Multi-objective FJSP Based on the Hybrid Algorithm
Authors: Liao Wen-jie , Fujimura Shigeru 
Published: August 2023

Abstract
The flexible job-shop scheduling problem (FJSP) is a critical model in manufacturing systems that assigns operations from different jobs to various machines. However, optimizing multiple targets during the production scheduling process is always necessary. While the non-dominated sorting genetic algorithm (NSGA-II) is an effective method to solve the multi-objective FJSP, it can have the main drawbacks of converging too early and falling into local optimization. To address these issues, this research proposes a hybrid algorithm that combines NSGA-II and multi-objective simulated annealing using a pareto-domination based acceptance criterion (PDMOSA). The PDMOSA has a powerful search performance that can overcome the limitations of NSGA-II. The hybrid algorithm also includes original modification methods such as a deletion criterion, duplicated solution deletion, and new individual adding. Additionally, a plug-in decoding method is introduced. The proposed hybrid algorithm is compared with several improved ways based on NSGA-II in various experiments. The results demonstrate that the performance of the hybrid algorithm is better than the others in multi-objective FJSP.