bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of calculation conditions for transition process of pumped storage power station
Authors: Ren Taozhe , Cheng Yanan , Wang Jue , Zhao Long 
Published: June 2024

Abstract
The calculation of transition process of pumped storage power station needs to consider many complicated working conditions. By studying the transition process calculation conditions of industry regulations and actual power stations, this paper analyzes the parameters that affect the transition process calculation, comprehensively considers the safety and economic benefits of power stations to determine the main calculation conditions, and puts forward the conditions that should be paid attention to in the transition process calculation of pumped storage power stations, so as to provide references for the selection of transition process calculation conditions of relevant power stations.
Hydraulic transient calculation by wave tracking method for pumped storage power plant with four units in a diversion system
Authors: Yin Xinyue , Zeng Zongyao , Wang Yuchuan , Chen Hongyu , Ma Dong 
Published: June 2024

Abstract
Hydraulic transient calculations are a key issue related to the operational safety of pumped storage power plants. Based on the new calculation method, wave tracking method, this paper establishes a calculation model for the hydraulic transient of pumped storage power plant, verifies the accuracy of the calculation model through hydraulic model experiments, and calculates the transient process of Guangdong Qingyuan pumped storage power plant. The results show that the calculation error is reduced by considering the difference of wave velocity of different branch pipes by wave tracking method. The wave tracking method is convenient to establish a calculation model of pumped storage power plant with four units in a diversion system, which is suitable for the load shedding transient regime of the turbine mode and the pump outage condition, and the accuracy is good. Wave parameters visually show the connection between flow rate, pressure changes within the water transmission system, and surge fluctuations in the regulator well throughout the hydraulic transition.
Study of Hydrofoil Unstable Partial Cavitation Emphasizing Unstable Sheet Cavitation Phenomenon
Authors: Wang Lin , Tang Fangping 
Published: June 2024

Abstract
Unstable partial cavitation phenomenon often occurs during the operation of axial flow pumps. In this paper, the hydrofoil of an axial flow pump is taken as the research object, and the cavitation morphology at the design angle of attack is obtained by high-speed photography. And the flow characteristics under the transformation cavitation number of sheet cloud cavitation are studied by SBES turbulence model. The hydrofoil has hydrodynamic phenomena such as unstable sheet cavitation and multistage cloud cavitation. The high pressure propagating upstream from the trailing edge may be the cause of secondary cloud shedding, and the closer to the hydrofoil wall surface, the greater the intensity of this pressure. The frequency of unstable sheet cavitation shedding is 166.6 Hz. The instable closure of cavitation and the hydrofoil wall may be the main cause of unstable sheet cavitation formation. The generated quasi-periodic re-entrant jet will have a greater impact on the flow in the rear of the hydrofoil. This study provides reference for the design and operation of axial flow pumps and prevention of cavitation damage.
Numerical simulation on unsteady cavitating flows in a rotational hydrodynamic cavitation reactor
Authors: Meng G Q Q G , Zhou W J , Jia Y F 
Published: June 2024

Abstract
The RNG k-ε turbulence model and mass transport cavitation model Zwart-Gerber-Belamri are used to simulate unsteady cavitating flows in a rotational hydrodynamic cavitation reactor (RHCR). The RHCR is mainly composed of rotor and stator. Unsteady cavitation flow field analyses in RHCR are focused mainly near the rotor surface. The numerical simulation results are in good agreement with the experimental data. The frequency of pressure fluctuations and streamline distribution are discussed by setting 10 monitoring points near the rotor surface. The numerical simulation results shows that the main frequency of pressure fluctuation inside RHCR is 24f
r and 72f
r; the maximum amplitude of pressure fluctuations appears near the inlet, and its value about 3 times than the minimum. Moreover, the streamline distribution analyses demonstrate that the vortex appears near the rotor surface, and is generating, growth and disappearing with time. The shape, vortex center and intensity of the vortex near the inlet change drastically with time. This research provided a reference for the optimization design of RHCR.
Degradation of tetracycline by combining hydrodynamic cavitation (HC) and persulfates (PS)
Authors: Zhu Xiufeng , Xuan Xiaoxu , Manickam Sivakumar , Yoon Joon Yong , Wang Jingying , Sun Xun 
Published: June 2024

Abstract
The ecological and human health risks caused by the overuse of antibiotics have aroused widespread concern. Due to the characteristics of antibiotics themselves, they cannot be effectively removed by traditional treatment methods. HC is considered as a new and innovative chemical process enhancement technique. which exhibits remarkable efficiency in degrading stubborn organic pollutants, and can effectively cooperate with various physical and chemical methods. In this study, the hydrodynamic cavitation (HC) technology was used to activate peroxymonosulfate (PMS) and peroxodisulfate (PDS) to produce strong oxidizing active substances (SO4
-•) to degrade tetracycline (TC) wastewater with an initial concentration of 30 mg/L. The results show that a positive relationship between the degradation efficiency of TC and both the inlet pressure as well as the dose of PS applied. HC can enable full activation of PMS and PS, the max synergistic index of HC-PMS and HC-PDS was 1.72 and 24.81, respectively. Therefore, the HC-PS system can provide a novel technical route for the treatment of antibiotic wastewater.
Degradation of tetracycline by combining hydrodynamic cavitation (HC) and ultraviolet (UV)
Authors: Liu Shuai , Xuan Xiaoxu , Manickam Sivakumar , Yoon Joon Yong , Leung Dennis YC , Sun Xun 
Published: June 2024

Abstract
Antibiotics have become a new type of organic pollutant. Traditional methods of antibiotic treatment have several problems, including low treatment efficiency, high cost, and low safety. As an emerging process intensification technology, hydrodynamic cavitation (HC) can significantly enhance degradation efficiency coupling with other treatment means. This work studies the degradation effect of a representative antibiotic, tetracycline, by combining HC and UV. The effect of various operating factors, including inlet pressure, initial concentration, pH, and temperature, is analyzed. It is found that HC/UV can obtain 1.7∼4.2 times more effectiveness than that of sole use of HC or UV.
Experimental and numerical studies on the partial cavitation in a Venturi
Authors: You Weibin , Xuan Xiaoxu , Chen Songying , Yoon Joon Yong , Sun Xun 
Published: June 2024

Abstract
To effectively control the adverse effects of cavitation, it is crucial to understand the mechanism behind the formation of cloud cavitation. The transition from sheet to cloud cavitation, or cavitation shedding, can be caused by two mechanisms: re-entrant jet and condensation shock. This study investigated the shedding mechanism of partial cavitation in a Venturi using high-speed photography and Large-Eddy Simulation. The Rankine-Hugoniot equation was used to verify that the cavitation shedding mechanism: the condensation shock at σ = 0.37 and the re-entrant jet mechanism at σ = 0.98. Both operating conditions exhibit backflow, which can cause variations in image grayscale values. The relation between backflowing velocity and grayscale variation was identified in different shedding mechanisms. When the adverse pressure gradient is constant, the shock velocity is inversely proportional to the image grayscale variation, while the re-entrant jet velocity is proportional to it. These findings may contribute to a better understanding of cavitation shedding mechanism.
Effects of cavitation on the vortex shedding behind a truncated hydrofoil subjected to forced oscillation
Authors: Chen Jian , Escaler Xavier 
Published: June 2024

Abstract
Cavitating vortex shedding behind a truncated NACA 0009 hydrofoil subjected to forced oscillation has been numerically investigated using a one degree-of-freedom (1 DOF) model coupled with a homogeneous mixture cavitation model. The pitching motion of the hydrofoil has been prescribed using a sinusoidal function with a fixed amplitude and variable frequencies ranging from lock-off values below the vortex shedding frequency to values well above it and passing through the lock-in condition. The obtained results have permitted us to study the change in the dynamics and morphology of the shed-vortex structures with varying hydrofoil oscillation frequencies when cavitation takes place. More specifically, it has been found that the frequency regime of the lock-in condition is altered due to the occurrence and development of cavitation. Also, two distinct wake patterns have been observed for oscillating frequencies below and above the vortex shedding frequency. Furthermore, the phase angle between the applied torque and the hydrofoil surface acceleration has been estimated as a function of the excitation frequency and the cavitation number, which has helped to understand the effects of cavitation on the dynamic behaviour of the shed vortices.
Study on acoustic characteristics of bubble interaction
Authors: Qi H Y , Sun X Y , Liu J T 
Published: June 2024

Abstract
Bubble flow exists widely in various hydraulic systems. The shape and size of the initial bubble deformed from a nozzle/orifice have a significant effect on the dynamic characteristics of the rising processes. In the monitoring of the sound signal of the bubble flow, it is found that the bubble will produce the sound signal when it detaches and rises, and the bubble flow pattern is related to the acoustic signal. In order to better understand the physical mechanism of passive acoustic emission, the acoustic characteristics of different nozzle arrays and gas flow rates were studied. The bubble acoustic statistical characteristics are obtained by filtering. The spectrogram based on time-frequency analysis is used to count the formation of individual bubbles and also to show the transient behaviour of bubble acoustics. Synchronous analysis is applied to study the image information and acoustic signal characteristics, the corresponding relationship between the flow pattern and the acoustic texture feature is established. This will provide a reference for predicting flow patterns through acoustic signals, and is significant for improving work efficiency and detecting faults.
Study on the Influence of Protuberance Amplitude on the Performance of Vertical Axis Wind Turbines
Authors: Chang H , Li D Y , Wang H J , He Y R , Zuo Z G , Liu S H 
Published: June 2024

Abstract
The performance of vertical axis wind turbine (VAWT) is mainly affected by the dynamic stall process of the blade. Inspired by the anti-stall performance of the humpback whale flipper, leading edge protuberances (LEPs) are applied to 2-blade VAWT. Based on computational fluid dynamics simulation method, the effects of LEPs amplitude on VAWT performance are investigated when blade tip speed ratio is 2.19. The results show that the larger the amplitude of the LEP, the lower the average power coefficient. When the number of protuberances is 3, the average power coefficient of the VAWT with a protuberance amplitude of 6.625mm is 1.8% higher than prototype blade. Considering the impact of increasing the chord length of biomimetic blades, the average tangential force coefficient of all biomimetic VAWTs decreases. The peak section performance of the bionic blade decreases significantly while the trough section performance increases significantly. The difference between the peak section and trough section of the LEPS plays an important role in improving the performance. This study provides a reference for the application of bionic protuberances in VAWTs.
Data acquisition in a simplified turbine model for prediction of unsteady vortex phenomena
Authors: Skripkin S , Suslov D , Gorelikov E , Tsoy M , Litvinov I 
Published: June 2024

Abstract
The utilization of machine learning in finding decisions of engineering problems is the optimal way. This study presents a new tool that applies machine learning algorithms, to predict the frequency response of an unsteady vortex phenomenon known as the precessing vortex core (PVC) that appears in a conical draft tube behind a runner. The basic values involved in Linear Support Vector Classification model training are the two components of the time-averaged velocity profile at the cone diffuser inlet and cone angle which should be accurately measured. The paper introduces the approach to accumulating an experimental database and conducting primary analysis of the implemented regimes of swirling flow in a simplified hydraulic turbine model. It was obtained that it is necessary to clearly identify the zone of recirculation flow. The presence of this zone is a necessary, but not sufficient condition for the formation of the PVC in the flow. Injection of an axial jet in a situation with moderate swirl flow allows to shift the PVC frequency about by 10% relative to the PVC frequency without an additional jet.
Intelligent Positioning System Design for Bridge Crane in Hydropower Plant
Authors: Chen Tiehua , Xu Ming , Zou Yanze , Wu Guangxin , Zhao Xinyu , Pan Yu 
Published: June 2024

Abstract
The compound nested control method of PID control and fuzzy control is used to control the walking position and speed of the bridge crane, and image processing technology is applied to detect the critical position during rotor hoisting. The system simulation is carried out using Matlab/Simulink, and the feasibility of the control method is verified based on the overshoot, response time, and stability indicators with the unit step signal as the excitation. The results show that the time required to reach steady state through fixed parameter PID simulation analysis is 0.237 s, and the overshoot is 3.3%. The time required for steady state using fuzzy PID control is 0.12s, the response speed is better than that of fixed parameter PID control, and the system has no overshoot. The image of the stator captured by the camera is processed by OpenCV. Firstly, the image is grayed and the Gaussian filtering is used to remove the image noise. Then, the stator edge contour is detected based on the Canny edge detection algorithm. The test shows that OpenCV can accurately identify the edge of the stator and extract the central coordinates of the stator image, which assists the bridge crane in accurate positioning.
Optimization conversion of integrated energy system under stepped carbon trading mechanism considering source-load uncertainty
Authors: Liu Yipeng , Zhang Yeke 
Published: June 2024

Abstract
This paper develops an optimization strategy for integrated energy systems under a stepwise carbon trading mechanism, considering source-load uncertainty. It aims to enhance operational efficiency and reduce carbon emissions within economic and environmental constraints. The strategy examines the impact of carbon pricing on energy management and leverages uncertainty for better energy efficiency and lower emissions. A case study confirms its effectiveness in improving energy utilization and reducing carbon footprint.
Energy-saving characteristics of pneumatic conveying based on the Dune model of elbow installation with different radius of curvature
Authors: Wang Yunfei , Yan Fei 
Published: June 2024

Abstract
During pneumatic conveying, particles undergo rapid horizontal movement and experience significant wear and collision when changing direction at the elbow pipe due to inertia. Consequently, to minimize energy consumption in transportation, a Dune model has been developed specifically for bends with varying radii of curvature. In this paper, the pressure drops the additional pressure drop coefficient, and the energy loss coefficient of the system are studied. At the minimum pressure drop velocity, PIV is used to capture the particle velocity at different locations in the vertical pipe. The findings reveal that the Dune model installation successfully minimizes the minimum pressure drop velocity, and the maximum pressure drop velocity is reduced by 10.36%. In addition, the energy loss coefficient decreased by 11.56%. Particles in vertical pipes have greater axial velocity than particles in pipes without dunes.
Permanent magnet synchronous motor NFTSM control based on novel exponential convergence law and ESO
Authors: Ren Zhiling , Zhang Enpu 
Published: June 2024

Abstract
To solve the problems of slow convergence and serious system chatter in PMSM speed regulation of traditional exponential approach law sliding mode control (SMC), a PMSM fast terminal slip mode (NFTSM) beat free predictive current control (DPCC) strategy based on improved exponential control rate and extended sliding mode observer (ESO) is proposed. The non-singular fast terminal slip-mode controller based on improved exponential control rate and ESO is used in the speed loop. A new exponential approach law is proposed. The stability of the system is proved by using the Lyapunov function. The robustness of the speed controller is improved while reducing the vibration. DPCC control strategy based on ESO is adopted for the current loop to compensate comprehensive disturbance of the current loop. The experiment results show that the control strategy has good speed tracking performance and anti-jamming performance.
Analyses of non-clean surface compressor blade cascades’ aerodynamic performance deterioration
Authors: Bu Yinglei , Wang Chenliang , Wang Meng , Wang Yanhua , Ren Xin 
Published: June 2024

Abstract
The efficiency and dependability of the engine are directly impacted by the compressor’s performance, which is a crucial part of gas turbines. The blade cascade is significantly influenced by surface roughness in terms of flow characteristics and aerodynamic performance. In this study, the NACA65-410 airfoil is selected as the research object to investigate the variations in blade cascade performance and flow characteristics under different inflow and roughness conditions. The results show that the smooth surface blade cascade performs optimally when the Reynolds number increases from 120,000 to 200,000. As the angle of attack increases from -5° to 8°, the blade cascade performance deteriorates, and the degree of performance degradation increases with the increase in angle of attack. For the roughened blade cascade surface, the performance initially improves and then decreases as the equivalent sand grain density increases, and there exists a critical equivalent sand grain density that maximizes the blade cascade performance. When the Reynolds number is 120,000, the critical equivalent sand grain density is 225 μm, and when the Reynolds number is 160,000, the critical equivalent sand grain density is 111 μm. Based on the findings of this study, the degradation pattern of blade cascade performance can be predicted, and it can be utilized to enhance the overall performance of the compressor.
Preliminary design and optimization of heat transfer element for calorimeter in neutral beam injection system
Authors: Pan Zhuo , Xie Yuanlai , Tang Ning 
Published: June 2024

Abstract
The calorimeter is the primary high heat flux component of the neutral beam injection (NBI) system. To meet the requirements of China’s future high-power and long-pulse NBI system for efficient heat removal from the calorimeter, this study proposes a preliminary design for a calorimeter heat transfer element (HTE) mainly formed by vacuum brazing the front plate and back plate, featuring internal hypervapotron channels to enhance heat transfer. Parametric design and numerical simulations are applied to find the optimal channel parameters, including channel height (h), fillet radius (r), and slot width (s). Response surface analysis is used to process the results of the design schemes. The thermohydraulic performance of the optimized design under different channel flow velocities and heat flux densities is further analyzed. The results indicate that the optimal parameters are as follows: h=5 mm, r=1 mm, and s=1.5 mm. The h and s mainly influence HTE’s maximum temperature and pressure drop per unit length, respectively. The optimized design can meet the design criteria with a normal channel flow velocity of 10 m/s. To prevent the HTE pressure drop from surpassing 2 MPa, the channel flow velocity should not exceed 12 m/s. The design and optimization results of this study can serve as guidance for the engineering design of the calorimeter in China’s future NBI system.
Torque balance control of underwater dual-motor system
Authors: Liu Yuqi , Huang Yuanfeng , Xiong Bin , Bian Hui 
Published: June 2024

Abstract
The duocentric motor drive system is commonly employed in various fields such as the printing and dyeing paper industry and industrial production. As one of the dual-motor systems, the duocentric motor system sometimes causes torque imbalance due to sudden load changes during underwater operation. This imbalance seriously affects the coordinated operation of the duocentric motor system. Addressing these issues, this paper proposes a control approach utilizing a combination of speed and torque control to manage the duocentric motor system. Through simulation, this control technique is validated to enhance the operation capability of the duocentric motor while ensuring system stability and reliability.
The lithium battery state of charge estimation based on the fractional order unscented kalman filter algorithm
Authors: Jie Junzheng , Gao Yu , Liu Wenhui 
Published: June 2024

Abstract
In the assessment of the state of charge (SOC) of lithium batteries, it has been observed that the conventional integer-order second-order resistance-capacitance (RC) network falls short in accurately replicating the non-linear attributes and the precision of SOC estimation influenced by the internal polarization reaction within the battery. Thus, we present the incorporation of constant-phase element (CPE) and Warburg components to achieve a model with superior recognition accuracy compared to the conventional second-order equivalent circuit model(ECM). The parameterization is carried out using the particle swarm optimization algorithm, resulting in enhanced robustness of parameter identification. Later on, when we mixed the regular Unscented Kalman Filter (UKF) algorithm with the fractional-order model (FOM), we obtained an algorithm to estimate the SOC of lithium battery in real time, named FOUKF, and compared FOUKF with the integer-order Extended Kalman Filter (EKF) and UKF algorithms. This confirms that the model is reliable and the algorithm’s estimation is accurate.