bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical investigation of cavitation suppression of centrifugal pump based on the bionic humpback whale blade
Authors: Wang L K , Liang C , Luo X Q , Xie H , Zhu G J , Feng J J , Li C H 
Published: June 2024

Abstract
Cavitation is inevitable during the operation of centrifugal pumps, it leads to the decrease in head and efficiency, and induced pressure fluctuation. This paper takes low specific speed centrifugal pump as the research object, a method of inhibiting cavitation by bionic humpback whale blade is proposed, the SST turbulence model is used to numerically study the whole flow passage of centrifugal pump. Comparative analysis of the cavitation characteristic curves under design conditions, the effects of bionic blades on water vapour volume fraction distribution, static pressure distribution, turbulent kinetic energy, vorticity field, streamline were investigated, the variation laws of cavitation morphology under different cavitation numbers is clarified. The research provides theoretical support for improving the cavitation performance and operation stability of centrifugal pump.
Numerical Study on the Hysteresis Effect of Volute Pump with Stay Vanes Based on Vortex Dynamics
Authors: Su Y Y , Wu X D , Xu B , Feng J H , Zheng T P , Liu Y Y 
Published: June 2024

Abstract
The hysteresis effect of volute pump with stay vanes in the hump zone can aggravate the vibration and jumping of the units, which seriously threatens the unit’s safety and stable operation. The formation mechanism of the hysteresis effect in hump zone is analyzed by carrying out unsteady numerical simulation of the volute pump with stay vanes at medium-low specific speed based on vortex dynamics theory. The results show that hysteresis effect occurs in volute pump, the fluid inertia force in FID is smaller than that in FDD, and the fluid viscous force in FID is larger than that in FDD. The hysteresis effect is not only related to the Karman vortex generated by the flow separation of vane and guide vane, but also closely related to the stall vortex generated in the volute. This work may provide a guide way for the optimal design and stable operation of the volute pump with stay vanes.
Research and Application of Key Technologies for Ultra High Pressure Grouting of Yangjiang Pumped Storage Power Station in Guangdong Province
Authors: Shi Yunli , Liu Xueshan , Huang Yufei , Zheng Yueyang , Wang Yuezhi 
Published: June 2024

Abstract
The most effective guarantee measure for the permeability stability of reinforced concrete lined high-pressure waterways is grouting. The traditional grouting treatment techniques and specifications can not effectively adapt to construction projects with higher requirements. This paper comprehensively expounds the new theoretical research system and grouting engineering design method proposed through model test and inverse calculation, and introduces the construction technology and technical requirements of 10Mpa ultra-high pressure grouting in the engineering field in combination with the construction practice of Yangjiang Pumped Storage Power Station, so as to provide useful reference for the construction of high-pressure waterway of pumped storage power station project.
The layout design of water diversion system in Zhaoqing Langjiang Pumped Storage Power Station based on front well drill method
Authors: Jingwei Sun , Han Wu , Lu Zhao , Yan Shi 
Published: June 2024

Abstract
The water diversion system of pumped storage power station is usually the subcritical line of engineering construction progress. It is easy to develop into a critical line due to the influence of uncertain factors in the construction process. In order to further ensure the construction progress of the project, the water diversion system of Zhaoqing Langjiang Pumped Storage Power Station was planned to adopt the fast front well drill construction method in the mining industry. In order to adapt to the construction technology of front well drill construction method, the layout design of the water diversion system was studied and optimized by considering the topography and geology, engineering layout, hydraulics, construction organization and other aspects. Finally, the appropriate layout scheme of water diversion system was drawn up.
Analysis of OWC impulse turbine flow characteristics considering the blade tip clearance
Authors: Jiajie Liu , Yexiang Xiao , Jie Liu , Hao Lin , Haijun Li , Qingpin Du 
Published: June 2024

Abstract
Oscillating water column (OWC) ocean wave energy recovery device is a popular technology in current wave energy research, which possesses the advantages of a sturdy structure and low-maintenance requirements. The device recovers energy by unidirectional rotation in the reciprocating airflow generated by an impulse turbine. Its operational performance depends on the flow efficiency of the core component, the air turbine. In this paper, a prototype impulse turbine with blades tip clearance of 1 mm was considered, and the SST k-ω turbulence model is used to calculate the operating performance of the air turbine at different operating points. The calculation result shows that the efficiency of the turbine under the optimal operating conditions is about 51.41%. When the flow coefficient is less than 0.8, the primary focus of energy loss in the rotor occurs at the blade tip. The low flow rate leads to a high inlet angle causing fluid friction. In these small flow conditions, the pressure drop at the leaf top gap is cantered on the inlet, and the speed in the gap flow field is significantly reduced. When the flow coefficient is greater than 1.4, the concentration of energy loss in the rotor primarily occurs within the flow channel, where the high-velocity air causing a local high-speed zone.
Investigation on hydraulic characteristics of a model and prototype bulb turbine based on similarity criteria
Authors: Zhou Xuezhi , Luo Yongyao , Wang Zhengwei , Ahn Soohwang , Luo Hongyun , Wu Yibin , Zhou Jingming 
Published: June 2024

Abstract
From the perspective of the world hydropower utilization trend, the medium and high head hydraulic resources are gradually decreasing, and along with much more attention to the ecological environment and land resource constraints, low-head hydropower plants have been becoming particularly prevalent. Benefit from compact structure, less investment, high capacity and wide operation range, bulb tubular turbines have come up to be the optimal option for the development and exploitation of low-head energy resources and been widely applied. In this paper, based on measurement data and CFD simulation results of model and prototype, scale effect which derived from similarity law was picked up to investigate the hydraulic performance and operating properties. Through comparison and analysis, it’s concluded that distinct from high-head application similarity conversion turns out to be more complicated for bulb turbines in case of flow characteristics, and it’s recommended that this conversion be further modified considering different boundary conditions. Such achievements will be of great help to look into the mechanism of ratio effect and accelerate research progress.
Technical Characteristics and Application Introduction of Horizontal Shaft Francis Double Runner Hydro Turbine Unit
Authors: Kuang Ding , Zujia Chen 
Published: June 2024

Abstract
Horizontal shaft Francis turbine generator units are widely used in small hydropower stations due to their simple structure, small civil engineering quantities, and convenient daily maintenance. However, some hydropower stations with large flow variation have certain problems with the stability of turbine operation under low load and small flow conditions. To adapt to large flow variation, increasing the number of units and reducing the unit capacity will significantly increase project investment, this paper introduces a horizontal shaft Francis double runner type hydro turbine unit, which has a wider power range for stable operation and a larger applicable flow variation, providing a new idea for the selection of small hydro turbine units with large flow variation.
Quantitative analysis on influence factors of power response rapidity of pumped storage units
Authors: Chen Jingdan , Yang Weijia , Li Yulan , Liao Yiwen , Huang Yifan , Qian Yiming , Chen Qiao 
Published: June 2024

Abstract
The rapidity of power response in pumped storage units (PSUs) plays a crucial role in their regulating performance within power grids. Consequently, it is essential to conduct a quantitative analysis of the power response power response rapidity. A numerical simulation method is adopted to investigate the fastest power response of PSUs and the corresponding response conditions. By considering two real power plants in China as case studies, the influence of characteristics of control and hydraulic systems on the power response rapidity is examined. In addition, by giving six different power commands, the fastest response of PSUs under the influence of multivariate coupling is explored. The findings reveal that the maximum power response rates of the two plants are 8.361%/s and 11.848%/s respectively in this work. The quantitative analysis can provide a reference for the fast power response and parameter optimization of pumped storage plants.
Selection of rated head of a pumped storage power station
Authors: Zhao Long , Cheng Yanan , Wang Jue 
Published: June 2024

Abstract
Rated water head is one of the important parameters of pumped storage power station, which is of great significance to the safe and stable operation of the power station. However, at present, there is no unified regulation on the selection of rated head of pumped storage power stations at home and abroad. Based on the relevant technical documents and selection standards, combined with the unit manufacturing, stable operation, kinetic energy utilization, project investment and other aspects of specific projects, we finally conclude the rated head recommendation scheme of the power station, which can provide a certain reference for similar pumped storage power stations.
Influence of different turbulence models on tip vortex prediction
Authors: Fang Mingkun , Li Na , Tao Ran , Xiao Ruofu 
Published: June 2024

Abstract
Tip vortex cavitation usually occurs in marine propellers and axial-flow turbines, the cavitation in the tip vortex could potentially result in blade erosion, at the same time, it will cause the pump vibration and noise emission. The tip vortex mainly occurs in rotating machinery with complex three-dimensional flow, but the prediction of the hydrofoil tip vortex can provide a basis for the study of the blade tip vortex in rotating machinery by simplifying the blade model. Hence, in this paper, we use the commercial software CFX to investigate the impact of distinct turbulence models on the configuration of tip vortex distribution in the NACA 16-020 hydrofoil, including SST (Shear Stress Transport), DES (Detached Eddy Simulation), LES (Large Eddy Simulation) turbulence models which are widely used in the field of rotating machinery. At the same time, the axial and radial velocity distributions at different locations downstream of the tip of the hydrofoil are compared to analyse the effects on the velocity distribution near the vortex core line stemming from various turbulence models. By comparing with the experimental data, the most accurate turbulence model for tip vortex prediction is obtained, which will provide guidance for the next step tip vortex prediction and the control of tip vortex flow.
On the validation of the cavitation model considering the thermodynamic effect of cavitating flow
Authors: Yu Lu , Geng Da , Liu Xin , Liu Shuhong , Zuo Zhigang , Zeng Chongji , Li Hui 
Published: June 2024

Abstract
It is known that when choosing water as a substitution of liquid hydrogen and liquid oxygen for cavitation investigations, the influence of thermodynamic effect should not be ignored. However, due to the lack of systematic experiments, most existing simulating studies use the average dynamic characteristics obtained earlier in 1970s for simulation validation, which may not be effectively accurate. In this paper, the unsteady experimental observations of cavitating flow on flat plate hydrofoil are presented in detail with the help of the advanced water tunnel in Tsinghua University, which is conducted in 2020s. Then the effectiveness of the numerical method considering the influence of thermodynamic effect is further verified with these dynamic observations. Results show that the method is effective and reliable, capturing the main features of the cavitating flow. And it can be used to simulate the cavitating flow considering the influence of thermal effect in the future.
The influence of structure parameters on the pressure characteristics of spillway tunnel
Authors: Funan Chen , Xiaoying Huang , Yang Xue , Gaohui Li , Weijie Cui 
Published: June 2024

Abstract
Cavitation is one of the key challenges of high-head and large-discharge spillway tunnel. The high-speed flow may cause a sudden drop in pressure in the case that spillway tunnel built without suitable shape or smooth surface. Meanwhile, the complex flow pattern accelerates the occurrence of cavitation. The anti-arc section is usually set at the end of spillway tunnel for trajectory bucket type energy dissipation, and a horizontal section may be set upstream of the anti-arc section to adapt to local topography. It’s necessary to conduct in-depth research on the pressure characteristics of horizontal section and anti-arc section to prevent cavitation. In this paper, the pressure distribution along the spillway tunnel is calculated using VOF method. The influences of the length of horizontal section, the radius of anti-arc section and arc section are studied. The results show that the horizontal section suffers low pressure. Reducing the radius of anti-arc section is effective for raising the pressure in horizontal section. However, the minimum pressure cannot be raised when the length is larger than a certain value.
Simulation of the Effect of Particle-bubble Size Ratio on the Collapsing Dynamics of a Cavitation Bubble Near a Particle
Authors: Zhang H , Dai Y , Yang J Q , Chen T 
Published: June 2024

Abstract
The synergistic effect of cavitation bubbles and sediment particles on material damage is a significant problem in fluid machinery. The dynamic behavior of a cavitation bubble near a spherical particle were simulated in this study using the Volume of Fluid (VOF) method. The effects of the particle-bubble size ratio δ on the bubble profiles, the collapse time, the micro-jets and the pressure at the particle surface have been investigated under the conditions of three values of stand-off distance γ. The results show that (1) the bubble collapse time rises as the particle-bubble size ratio δ increases; (2) the peak values of the maximum jet velocity and the maximum pressure exerting on the particle appear at γ = 1.0 and δ = 1.2, which are 165.3 m/s and 10.46 MPa, respectively; (3) the influence on the particle caused by the micro-jets cannot be ignored when the stand-off distance is less than 1.5.
Effect of structural parameters of biomimetic jellyfish on propulsive performance
Authors: Miao Xingyu , Liu Jinzhe , Li Kailin , Zhang Ruihan , Gao Li 
Published: June 2024

Abstract
Based on numerical simulation technology, the dynamics simulation of a two-dimensional jellyfish model was carried out. The study analyzed the changes in the surrounding flow field with variations in the jellyfish’s shape during its biomimetic movement. Additionally, it explored the impact of parameters such as the head-body ratio and the ratio of open-close time on the propulsion performance of the biomimetic jellyfish. The research findings revealed that reducing the head-body ratio and increasing the ratio of open-close time improved the propulsion performance of the jellyfish. Specifically, decreasing the head-body ratio resulted in a greater increase in thrust, while increasing the ratio of open-close time led to a smaller enhancement in thrust.
The dynamical response of turbulent flow to bed deformation under submerged discharge and plane vertical impinging jets
Authors: Tingting Liao , Huating Xu 
Published: June 2024

Abstract
On the conditions of discharge under sluice gate and vertical jets, the research on the dynamical response of hydraulic elements to bed deformation is much concerned in the field of high-speed flow and hydraulic dredging but not be solved yet. Research achievement from numerical simulation are drawn as follows: (1) Under sluice gate discharge condition, the response of hydraulic elements to bed deformation is that the bed is deforming in the direction of the mechanical energy loss, the rate of the bed deformation and the mechanical energy loss near the local scour hole and the horizontal distance from the reattachment point to the maximum scour depth are all continuously varying with the scouring of time and synchronously approaching to its own certain value. (2) Under vertical jets discharge condition, the response of hydraulic elements to bed deformation is that the rate of bed deformation and the pressure of the maximum scour depth is monotonous continuously decreasing with the scouring of time and synchronously approaching to its own certain value.
Numerical simulation of sand erosion in Venturi tube under different flow characteristics and sand content
Authors: Pan Jiale , Guang Weilong , Liu Qiang , Lu Jiahao , Tao Ran , Zhu Di , Xiao Ruofu 
Published: June 2024

Abstract
In the solid-liquid two-phase flow, there is flow erosion of solid relative to the surrounding wall or other components, which has attracted the attention of many scholars. Wherever flows are involved, erosion tends to be a problem. Especially in rivers with large sediment content, hydraulic machinery including pumps, water turbines, reversible water pump turbines and pipelines in a long time of flow erosion, it is easy to cause the material damage of the flow parts, affect the head and efficiency to a certain extent, may also lead to the increase of the gap between the flow parts resulting in noise and other hazards. However, in different flow conditions, the location of erosion is different, which makes it difficult to prevent erosion. As a common measuring tool, Venturi tube has a certain representative geometric shape. The erosion prediction of Venturi tube by computational fluid dynamics can provide a certain reference for other structures. In this study, the solid-liquid two-phase flow analysis method based on CFD was used to analyze the flow erosion under different velocity and sediment content. Through numerical simulation, it is found that the erosion problem in Venturi tube is closely related to its flow characteristics.
Research on contact stiffness of tenon jointed turbine bladed disk under time-varying load
Authors: Qu Zhen , Yao Can , Honglai Zhu , Lin Xingrong , Chen Lei , Hu Heran 
Published: June 2024

Abstract
Tenon-jointed turbine blades will be impacted by airflow and centrifugal force during the high-speed rotation of the engine. The surface contact stiffness of the tenon and tenon groove will change with complex external loads. Through the analysis of the micro-morphological characteristics of the contact surface of the tenon joint bladed disk, the contact characteristics of the asperities on the rough surface are determined. At the same time, to solve the problem that the traditional microscopic contact stiffness calculation formula cannot be applied to the tangential displacement load, the periodic piecewise tangential stiffness expression is derived based on external loads of the normal force and the equivalent tangential force. Furthermore, this paper studies the properties of the tangential stiffness curves under different external load frequency ratios and phase differences. An increase in the frequency ratio will decrease the step value of the piecewise function and make it tend to a smooth transition. The change of the phase difference will directly change the monotonicity and fluctuation of the stiffness curve. The macro and micro theoretical analysis methods of contact characteristics have been established.
Numerical simulation analysis and experimental verification of air flow measurement in large-diameter S-shaped pipe
Authors: Jia Lu , Zeng Yongzhong , Liu Xiaobing , Yu Zhishun 
Published: June 2024

Abstract
The ventilation systems in nuclear power plants, hydropower plants, and other large-scale projects involve the transportation of fluids through large-scale pipelines. To achieve a more stable flow velocity distribution, the fluid needs to pass through a straight pipe section of sufficient length upon entering the pipe. Typically, this straight pipe section should be at least 15 times the inner diameter of the pipe. However, for large-diameter irregular square pipes with a diameter exceeding 1m, where the curved section is short and there are no long straight pipe sections before and after it, the flow field inside the pipe becomes complex, requiring accurate measurement of the flow rate.In this regard, a numerical simulation analysis is conducted to address this challenge. A mean velocity evaluation method based on the coefficient of variation is proposed. This method identifies multiple points within the pipe that best represent the average flow velocity, determining the insertion depth of sensors and the weight coefficients of these multiple measuring points. A calculation formula is derived, utilizing the cross-sectional average velocity as a function with the velocity values at multiple points in the flow field as independent variables. To validate the accuracy of the proposed method, flow measurement experiments are performed on a wind tunnel test bench. The calculated values obtained from the derived formula through numerical analysis are compared with the experimental results. The relative error within the full range is found to be less than 0.54%, confirming the accuracy of the formula. The research findings present a novel measurement method for airflow in large-diameter irregular square pipes and offer valuable practical insights for engineering applications.
Study of the Measurement Method on the Dynamic Stress and Pressure of Model Pump-turbine Splitter Blades
Authors: Yingnan Zhao , Xiaolong Yang , Huanmao Wang , Kai Lin , Jinwei Zhang , Xingchun Lei , Yue Zhao , Wei Zhao 
Published: June 2024

Abstract
The operation conditions of the pump-turbine are changed frequently and are worse than the conventional turbine. The operation stability of the pump-turbine is more focused with the incremental unit capacity and the pump-turbine runner diameter. The research of the measurement method for the dynamic stress and the pressure of the model pump-turbine splitter runner blades is performed to evaluate the stress and pressure distribution under the various operation conditions, it is optimized for the turbine mechanical and hydraulic computation, the operation references are provided for the prototype pump-turbine also. In this paper, the measurement positions of the blades are determined based on the hydraulic CFD and mechanical computation, the measurement method of dynamic stress and pressure of model pump turbine-runner splitter blades is studied.