bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on load rejection test of pumped storage units
Authors: Luo Guohu , Wang Xi , Zhao Wenjun , Huang Shaozheng , Li Jinwei 
Published: June 2024

Abstract
The rise rate of rotating speed, the maximum inlet pressure of the spiral casing and the minimum inlet pressure of the draft tube cone of unit 2 in Jinzhai pumped storage power station were analyzed when 50% and 100% of the rated load were rejected in this paper. The low pass filtering method (cut off frequency is 0.2 times of the frequency) was used to process the pressure data at the inlet of the spiral casing and the draft tube cone to retain the trend term. The peak to peak values (97% confidence) of the pressure pulsation term under different data durations were studied, which provided technical support for rational and accurate calculation of the maximum inlet pressure of the spiral casing and the minimum inlet pressure of the draft tube cone, and provided an example reference for the load rejection test analysis of pumped storage units.
Redesign of Adjustable Guide Vane Cascades of Pump Turbine and Its Effect on Self-Excited Vibrations at Slight Opening During Pump Mode’s Starting Up Process
Authors: Hao Z J , Wang M K , He Q Y , Shi Q H , Chen H , Ding X L 
Published: June 2024

Abstract
Abnormal sounds and vibrations have occurred at several pumped storage power stations, when the guide vanes are at a slight opening during the pump mode’s starting up process. This paper proposes a modification method for active guide vanes to reduce the probability of abnormal vibration caused by self-excited vibration. A set of real machine guide vanes was selected to investigate the influence of different geometric parameters on self-excited vibration. Comprehensive analyses were conducted on the modified blades by the unsteady Reynolds-averaged Navier-Stokes solver and the 1DOF oscillator model (URANS-1DOF) coupling simulations. The results indicate that the probability of self-excited vibration divergence of the guide vanes is closely related to the degree of contraction and diffusion of the narrow gap flow channel. The self-excited vibration of the guide vane can be effectively suppressed by selecting appropriate overlapping length, contraction coefficient and diffusion coefficient. In addition, model tests have verified that the modification method has a slight impact on hydraulic performance.
Study on vibration characteristics of pump-turbines with different runner characteristics
Authors: Li Hailing , Ren Shaocheng , Liu Yang 
Published: June 2024

Abstract
In terms of the problems of large vibration pendulum in some working conditions and obvious vibration sensation in local plant and water delivery system of Heimifeng pumped storage power station, test and analysis were carried out on two different runner units before and after transformation in the same flow channel, revealing the difference of pressure pulsation transmission characteristics and vibration response of different runner hydrostatic interference. The test results show that the modified runner with long and short blades is feasible and effective for reducing the pressure pulsation caused by dynamic and static interference and controlling the vibration of the plant, which can provide a reference for the vibration of the unit and the plant in the same type of pumped storage power station.
Optimization Analysis of Head Cover Structure of High Head Pump Turbine
Authors: Hong Zhang , Shihai Huang , Junpeng Zhou , Min Song , Weibin Song , Yanmei Ma 
Published: June 2024

Abstract
Head cover is one of the key components of the pump turbine. Its stiffness and axial stiffness have an important influence on the safe and stable operation of the unit. The structure of head cover is related to the design pressure. In this paper, the structure of head cover of the high head pump turbine is optimized, and the strength and axial stiffness of head cover before and after optimization was analyzed by finite element method. The results show that the optimized head cover is better than the axial stiffness of head cover before optimization.
Technical investigation of the ternary pumped storage hydro units with ultra-high-water head
Authors: Dongkuo Li , Zishi Liu , Hongping Min , Yexiang Xiao , Zhonghua Gui , Xiaodong Wang , Hao Lin 
Published: June 2024

Abstract
This paper introduces the ternary pumped storage hydro unit technology and its development status, discusses the technical characteristics of the ternary unit, and looks forward to the broad application prospect of the ternary unit technology in the ultra-high head pumped storage power station. The main technical advantage of the ternary pumped storage hydro unit by using the Pelton turbine as the turbine component is that the hydraulic short circuit operation mode of the combined operation of pump and turbine can realize the smooth adjustment of the input power of the unit pumping condition. In addition, the conversion time between working conditions is greatly shortened compared with the conventional reversible pumped storage unit, thus greatly enhancing the power grid’s ability to absorb and adjust new energy.
Research on the effect of anti-guide vane inlet Angle on the performance of multistage centrifugal pump
Authors: Chenhao Li , Lu Li , Xingqi Luo , Xitong Wu , Guojun Zhu , Jianjun Feng 
Published: June 2024

Abstract
Anti-guide vane is the component that converts energy and diversion flow in multistage centrifugal pump and its hydraulic loss is the main factor affecting pump performance. In this paper, the multistage centrifugal pump with radial guide vane is taken as the research object. Based on α5
=35° inlet angle of prototype anti-guide vane, two optimization schemes of reducing and increasing the inlet angle are proposed to obtain α5′=25° and α5′′=45°. The SST turbulence model is used to simulate the centrifugal pump before and after optimization. The internal flow velocity characteristics, blade load distribution and pressure pulsation characteristics of the multistage centrifugal pump anti-guide vane were studied. The results show that under large flow conditions, the pump head and efficiency are increased by 4% and 2.66% respectively. And the flow loss in the anti-guide vane is reduced by 6.02%, which greatly improves the unstable flow caused by the impact separation at the anti-guide vane inlet. The blade load increases with the decrease of the anti-guide vane inlet angle, and the pressurization benefit of anti-guide vane is the largest when α5′=25°. The vibration amplitude of pressure pulsation is the largest at the anti-guide vane outlet, and the amplitude increases with the decrease of inlet angle. The research results can provide reference for the optimal design of the multistage centrifugal pumps anti-guide vane.
Numerical and experimental study of tip leakage vortex structures and dynamics in a mixed-flow waterjet pump
Authors: Gong B , Zhu H L , Chen X H , Yin J L , Li N , Wang D Z 
Published: June 2024

Abstract
Driven by the pressure difference between pressure side and suction side, the tip leakage flow (TFL) and forms the tip leakage vortex (TLV), which interact with main flow and leads to instability of flow as well as cavitation in a mixed-flow waterjet pump. In this work, the characteristics of TLV are investigated by experiment based on high-speed photography (HSP) and the numerical simulation. The TLV trajectories predicted by numerical simulation’s shows a good agreement with the experiment test results. Cavitation of the TLV core due to low pressure forms a TLV core cavitation trajectory line. The start position of TLV trajectories and the relative angle between the TLV trajectory and the blade are significantly affected by the blade tip loading. The unsteady primary tip leakage vortex (PTLV) evolution process can be summarised in three stages of splitting, developing, and collapsing.
Numerical Investigation of Impeller Parameters on the Performance and Internal Flow Characteristics in Regenerative Flow Pumps
Authors: Tang Deli , Lu Yi , Li Qianqian , Ge Jian , Miao Xinting 
Published: June 2024

Abstract
As a particular vane pump, regenerative flow pump (RFP) is not only featured by relatively high head under low flow rate, but also is characterized by compact volume and simple structure. However, the efficiency of RFP is quite low. For the purpose of improving RFP’s hydraulic performance and internal flow, this paper investigates the influence of the matching relation between impeller diameter and height on RFP’s performance. Two cases through changing impeller’s diameter and height are designed and compared. The results show that, as impeller’s diameter increases while keeping the blade’s radial length constant, RFP’s head and efficiency are improved, and the best efficiency point (BEP) shifts gradually from lower flow rate to larger flow rate. Additionally, the ratio of the flow rates at BEP is approximately equal to the ratio of the blade’s middle diameters. On the other hand, as impeller’s height increases, the BEPs among different pump models stay in same flow rate, and there is always an optimal impeller’s height for this RFP model to achieve optimal performance. Finally, the pressure distribution, velocity distribution and mass exchange of different models are analysed to reveal the differences.
Optimization of Centrifugal Pump Impeller Based on Neural Network and NSGA-II Algorithm
Authors: Wei Chen , Wensheng Ma , Lei Wang , Meng Zhang , Qiang Zhang , Kaizi Huo 
Published: June 2024

Abstract
This article focuses on the multistage centrifugal pump secondary impeller as the research object, and the two performance parameters of head and efficiency are taken as the optimization objectives. Firstly, the range analysis of significant influence degree of impeller geometric parameters was carried out by partial factor test method. The blade inlet angle at the front and rear cover boards of the impeller, blade outlet angle and blade wrap angle as the optimization variables, two optimization schemes with different blade numbers were proposed. On this basis, the optimal Latin hypercube sampling method was used to extract samples from the two schemes, CFD technology was used to calculate the corresponding target value of each sample, BP neural networks with different structures were used to train the samples, and the agent model with the highest prediction accuracy was optimized as the population evaluation function of NSGA-II algorithm to search for optimization. The results show that the pump performance parameters have been improved after optimization of Scheme II, and the flow of the internal flow field conforms to the law. Finally, through the experimental verification, the optimized centrifugal pump head and efficiency increased by 3.21m and 3.05%.
Influence of impeller energy dissipation characteristics of multi-blade axial flow pump impeller by the cascade density
Authors: Zhao Sen , Yang Congxin , Guo Yanlei , Yingxiang Mo , Haoyu Cui , Lv Tianzhi 
Published: June 2024

Abstract
This paper investigates the influence of cascade density on energy dissipation in the impeller of a multi-blade axial-flow pump. Three-dimensional transient numerical simulations were conducted using the SST k-ω turbulence model for impeller schemes with different cascade density, corresponding to different blade chord length and pitch. Entropy production theory was applied to locate the regions with high energy loss in the impeller. The relationships between local entropy generation, energy loss, and unsteady flow were analyzed for different cascade density. The results indicate that impeller entropy output of the multi-blade axial-flow pump is highly consistent with the head loss during testing. Turbulence dissipation accounts for more than 50% of the total energy loss, followed by wall friction, while direct dissipation is the smallest contributor. The relative loss of the impeller can be minimized by decreasing the number of blades or increasing the blade chord length. By comparing energy dissipation in blade rotation with different chord length and pitch, it is found that turbulent dissipation ability can be controlled more effectively by changing chord length, while the ability of direct dissipation can be controlled more effectively by changing the pitch.
Study on the pulsation and fluid-structure coupling characteristics of rotating parts of vane type mixed-flow pump
Authors: Jin Yan , Xue Ying , Tang Fangping 
Published: June 2024

Abstract
Vane type mixed flow pumps (VTMFP) are widely used in water conservancy engineering, with a wide range of head applications. The impeller is the core component of the pump unit, and its internal flow and hydraulic excitation force affect the safe and stable operation of the unit. Aiming the pulsation characteristics inside the impeller, the VTMFP under different conditions is studied to examine the deformation and stress distribution by CFD, and the simulated results agree with the test data. The simulated results indicate that the impeller blade passing frequency consistently dominates the impeller inlet under various operating conditions. Furthermore, it is observed that the impeller rotating parts experience the highest levels of stress and deformation at low flow rate. The distribution of the equivalent force decreases from the hub to the shroud, while the deformation displacement decreases from the impeller shroud to the hub. In light of these findings, it is recommended that the design process takes into consideration the stress concentration near the blade root and the deformation at the blade edge.
Expression and prediction of pump and pumping station characteristics
Authors: Yan Dengfeng , Feng Xusong , Li Yanjun , Lu Weigang , Chen Songshan 
Published: June 2024

Abstract
According to the relevant literature of pumps and pumping stations and the expression and conversion method of pump efficiency and pump cavitation proposed by the author, through further careful mathematical deduction, the expression of pump and pump device characteristics is proposed. The proposed expressions for centrifugal pumps (and volute type mixed flow pumps) and axial flow pumps (and guide vane type mixed flow pumps) are applicable to both pumps and pump units; it is applicable not only to models, but also to similar prototype pumps and prototype pumping units of any diameter and parameters. The research and realization of performance expression of pumps and pump devices have great theoretical significance and practical application value for improving the design level of pumps and pumping stations and for accurately predicting the characteristics of pumps and pumping stations.
Optimization of Cavitation Performance of High-Speed Centrifugal Pump Based on the Meta-Model of optimal Prognosis
Authors: Wang Xiao-Hui , Zhang Kai , Miao Sen-Chun , Yang Jun-Hu , Shen Zheng-Jing 
Published: June 2024

Abstract
Using a specific type of high-speed centrifugal pump as an example, this study conducted a parameterized optimization design on geometric parameters of the impeller’s flow path. A response sample space was generated with the flow path geometric parameters as input and pressure increment and cavitation volume as output. Based on the Meta-Model of optimal Prognosis, the optimal surrogate model was fitted, and a global sensitivity analysis was conducted. The results indicated that the impeller’s inlet edge parameter and mid-curve parameter had a significant impact on the pressure increment and cavitation volume of the pump. Using a genetic algorithm, the optimal flow path geometric parameters were obtained, and numerical simulation methods were applied to verify the obtained parameters. The results showed that after optimization, the pressure coefficient of the centrifugal pump increased by 0.035, and the cavitation performance improved by 22.28%. The impeller cavitation area and void volume were significantly reduced, and the flow path pressure distribution and flow state were improved.
Study on the volute optimization and mechanism of vortex loss reduction for a centrifugal fan
Authors: Wang Wei , Wang Junlong , Cu Tingting , Zhang Lefu , Lu Jinlin , Feng Jianjun , Luo Xingqi 
Published: June 2024

Abstract
In order to reduce the flow loss in the volute and improve the efficiency of the centrifugal fan further, a new type volute with a diffusion profile was designed and optimized. The effects of diffusion angles were clarified by using numerical simulations and the method of design of experiment. The mechanism of vortex loss reduction of the diffusion-type volute was revealed. The results show that diffusion-type volute can reduce the flow loss in the volute by 30.8% compared with the original volute, and increase the efficiency of the fan by 2.24%. Parametric studies show that the diffusion angle of front disc has a great influence on the efficiency of the fan, and the effect of diffusion angle of rear disc is relatively less. Mechanism analysis shows that the diffusion-type volute can greatly reduce the vortex strength in the volute, especially eliminate the high-intensity vortex near the volute tongue. As a result, the volute loss is remarkably reduced. In addition, the diffusion-type volute can effectively reduce the amplitude of pressure fluctuation in terms of shaft frequency, characteristic frequency and broadband signals in the volute.
Design method and flow analysis of a mixed flow pump based on blade load control
Authors: Liu Demin , Lu Yangping , Tan Lei , Tang Ruoyu , Yan Ming , Wang Zhichao , Ding Xiaoli 
Published: June 2024

Abstract
Mixed flow pumps are commonly used due to their wide operating range. Load distribution is the key parameter of the inverse design of mixed flow pumps. In this study, an inverse design method using a quadratic function to control the blade load distribution is introduced to design a mixed flow pump. The hydraulic performance of the pump is calculated using numerical simulation, and then the internal flow is analyzed. The results show that the pump designed by this method has a high efficiency at the designed point and a wide operating range. The flow field is symmetrical along the circumference and varies uniformly along the impeller inlet to the impeller outlet. No flow separation and no unfavourable low-pressure area appear.
Research on the pitching hydrodynamic performance of pump-jet propelled submersible
Authors: Han W , Hou Y Y , Zhang T , Dong Y F , Xing Y F , Yang Y B , Bai L , Zhang Y K , Yang T , Zhao L L , Xue T Q 
Published: June 2024

Abstract
Most of the current research in the world on the dynamical characteristics of pump-jet propelled submersibles has focused on the dynamic response of non-vector propulsion. However, the dynamics characteristics of water jet vector propulsion by external bypass excitation have been neglected. Therefore, this paper explores the variable vector deflection angle-controlled pitching motion in the vertical plane of the submersible and the isokinetic constant linear pitching motion water motion. ANSYS software is used to perform numerical calculations to investigate the changes of drag and Lifting force with velocity under different navigation states. Conclusion: In the process of surfacing, the change trend of Lifting force and drag is the same: when adjusting the navigation deflection angle, it increases rapidly, and then when floating in a constant straight line, it gradually decreases, and finally, the decrease rate tends to level off; when the elevation angle increases, the change amplitude of drag and Lifting force increases. During the dive, the drag force decreases and the Lifting force increases, gradually, the rate of decrease of drag force and the rate of increase of Lifting force become smaller; when the pitch angle increases, the Lifting force decreases rapidly and the decrease of drag force becomes larger.
Research on multi-condition and multi-objective control of pumped storage unit optimized by improved multi-objective particle swarm optimization algorithm
Authors: Jiang Xiaoping , Xiu Tianning , Yu Hao 
Published: June 2024

Abstract
In order to maintain good control quality of the pumped storage unit regulation system during the switching of operating conditions, a multi-objective optimization framework based on improved multi-objective particle swarm optimization algorithm is proposed, which takes into account the control stability, rapidity and robustness under multiple working conditions. Firstly, the fractional order PID controller with higher applicability and flexibility is introduced to replace the traditional PID controller. Then, an objective function considering the ITAE index of low-head and medium-high-head conditions is constructed. On this basis, the multi-objective particle swarm optimization algorithm with pigeon swarm search operator, adaptive Cauchy mutation strategy and improved initialization method is used to optimize the controller parameters, and the multi-condition and multi-objective fractional order PID optimal control of pumped storage unit regulation system is realized. Through simulation, it is proved that the controller parameters based on the framework optimization proposed in this paper have strong adaptability and robustness under different working conditions, which provides a new idea for the optimal control of pumped storage unit regulation system.
Numerical investigation of the hydrodynamic properties of oscillating water column air chambers
Authors: Ding JiaWei , Chen Zhenmu , Zhu Baoshan , Xuan Dongji , Shen Yunde , Li Yong , Wu Mingge 
Published: June 2024

Abstract
The oceans occupy nearly 71% of the Earth’s surface area. The ocean is rich in energy, and wave energy is one of its important components. Therefore, the study of wave energy generation devices is an important issue. In this paper, we analyze the effect of the size of the air chamber structure on the OWC (oscillating water column) wave energy conversion device under the action of unidirectional regular waves. To analyze the performance of the OWC device under real sea conditions, the wave climate at Sanmenxia is used as the experimental parameter. The performance and characteristic response with the variation of incident wave height, air chamber width and front wall thickness, are analyzed. The results show that the incident wave height, air chamber width, and front wall draft have significant effects on the performance of OWC. With the increase of incident wave height, the wave nonlinear effect increases. As the air chamber width decreases, the horizontal surface inside the air chamber undulates smoothly and the standing wave phenomenon disappears.
POD mode analysis of the wake flow of Savonius hydrokinetic turbine runner
Authors: Guang Weilong , Pan Jiale , Liu Qiang , Lu Jiahao , Tao Ran , Zhu Di , Xiao Ruofu 
Published: June 2024

Abstract
The Savonius hydrokinetic turbine can be applied to ocean currents to improve the utilization of ocean current energy. To deeply understand the intrinsic correlation of wake flow field, this article analyzes the wake of the Savonius hydrokinetic turbine by combining proper orthogonal decomposition(POD). The results represent that the proper orthogonal decomposition can reconstruct the original wake velocity flow field to a high extent, accurately extract the main flow characteristics in the wake of the Savonius turbine, and effectively remove the flow field noise signal. In the wake of the Savonius turbine, there is a correlation between the high-order modes and the low-order modes extracted by the POD method. The decomposed flow field laws will support data-driven research in the future.