bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization method investigation for centrifugal pump performance based on 3D inviscid inverse design
Authors: Shen Zhenhua , Wang Chao , Ye Daoxing , Zhang Libin , Wang Peng 
Published: March 2024

Abstract
Centrifugal pump is widely used in many important fields such as large hydropower station, urban central heating, aerospace engineering, etc. It has high requirements for cavitation performance and hydraulic performance in actual use. This study centers around on a pipeline pump with a specific speed of 360, reconstructs the impeller in TURBOdesign, takes important parameters of the impeller as the input conditions for optimization, aims at enhancing the blade’s minimum pressure and curtailing the flow losses in the blade channel and progressively optimize the meridional-blade loading based on the inviscid flow which was carried out by using genetic algorithm. The optimization leverages genetic algorithm, progressively optimizing the impeller using meridional and blade loading. By analyzing the effects of meridional and blade loading parameters on cavitation and hydraulic performance, it is found that the optimized models’ NPSH are much better than the original one. It’s approved that this optimization method is valid.
Numerical research on performance failure caused by gas blocking in multiphase mixed-transport pump under non-uniform inflow conditions
Authors: Wang Zhisheng , Quan Hui , Feng Bing , Lan Jianying 
Published: March 2024

Abstract
The helical-axial multiphase mixed-transport pump fails due to gas blocking caused by gas-liquid separation caused by cavitation under complex conditions with high gas volume fraction. This is an urgent engineering problem that needs to be addressed in the application of this pump. In order to simulate the flow structure characteristics in the channel, two types of non-uniform inflow boundary conditions were introduced. The bubble structure, velocity, and pressure under different inflow conditions were compared and analyzed, and the variation patterns affected by non-uniform boundary conditions were obtained. At the same time, the internal flow characteristics and mechanisms of multiphase mixed-transport pump are analyzed based on the velocity changes at the inlet of the impeller and the pressure fluctuations at the outlet of the guide vanes, leading to the intensification of gas-liquid separation and eventually the development of gas blocking. Research has shown that through programmatic control of the inlet boundary conditions, a linear change in inlet pressure has a more significant effect on the intensification of gas-liquid separation in the flow channel of the mixed-transport pump than a sinusoidal change, ultimately leading to significant performance failure when generating gas blocking. The research conclusion provides reference value for solving gas blocking in engineering applications of helical-axial multiphase mixed-transport pump.
Integrated design and hydraulic model optimization of model horizontal main pump based on CFD fluid dynamics analysis
Authors: Lu Jinqi , Wang Dezhong 
Published: March 2024

Abstract
There are few studies and reports related to horizontal main pumps for nuclear power plants. The installation of vertical main pumps for small reactors requires the design of special elbows on the pressure vessel. Horizontal main pump, as a new main pump structure, can reduce the diameter of the main pressure vessel and simplify the structure of the pressure vessel. Compared with the vertical main pump, the horizontal main pump needs to control its axial dimension to improve its stiffness, which makes it impossible to set a long straight pipe section at the inlet, which has an impact on the pump performance. On the other hand, the compression of the axial dimension of the pump casing makes the overflow area of the press-out chamber small, resulting in large hydraulic losses. In this paper, in order to improve the efficiency of the pump and reduce the influence of non-uniform incoming flow, the optimization design is carried out with the SST k-ω model, and it is shown that: 1. the suction port of the curved impeller is easier for the fluid to enter into the impeller in the axial direction; and 2. the axially symmetric worm gear produces more vortex flow losses.
Research on prediction method of sensorless measurement of centrifugal pump operational state based on hybrid model
Authors: Gong X B , Gan X C 
Published: March 2024

Abstract
Centrifugal pumps are widely used in various fields such as industrial production and urban water supply. In order to achieve the monitoring of operational state of pumping systems, as well as the problems of inability to install sensors or high cost of sensors in practical engineering, the sensorless estimation method of centrifugal pump operational state provides a new opportunity for the monitoring and control of pumping systems. In this paper, a hybrid model based on QP model and neural network model is proposed to estimate the flow rate of rational pump by dividing the speed region. Taking a centrifugal pump as the research object, the operational points of the pump at different rotational speeds are acquired by experiments. Using the proposed method, a prediction model is established to predict the operational state of the pump. The prediction results are verified through experiments, and the error analysis of the prediction results is carried out. The results show that the proposed hybrid model can improve the prediction accuracy of centrifugal pump operational state and has certain practical value of engineering.
Experiment of cavitating flow characteristics of inducer with inflow entrained air
Authors: Lin R H , Chen H , Xiang L , Qu N C 
Published: March 2024

Abstract
To study the effect of inflow entrained non-condensable LOX tank pressurization gas on cavitating flow inside inducer pumps, a series of experiment were performed. The cavitation head breakdown point and cavitation instability characteristics of an inducer pump under different inlet gas volume fraction(IGVF) were investigated. It was found that head breakdown occurred at higher cavitation number under higher IGVF condition. Analysis of low frequency pulsating pressure suggested that cavitation surge was supressed by extra compressibility provided by non-condensable gas at operating point near head breakdown.
Design and numerical simulation of elliptical claw-type hydrogen circulation pump rotor
Authors: Feng Bing , Quan Hui , Wang Zhisheng 
Published: March 2024

Abstract
The claw-type hydrogen circulation pump has the advantages of smooth gas delivery, wide range of adapted working conditions, high efficiency, etc., which is the key equipment of the fuel cell system. In this paper, a new type of elliptical claw rotor is proposed by the combination of elliptical line, circular arc and pendulum line, and the equation of the line is calculated and deduced, and the distribution law of the flow field in the working chamber is obtained based on numerical simulation, and the internal flow characteristics, the working process, the change rule of the pressure, speed and the resisting moment are analysed. The results show that the elliptical claw rotor is subjected to a smaller gas resisting moment compared with the traditional cycloidal hydrogen circulating pump.
CFD study on the effect of particle properties on the performance of annular jet pump
Authors: Liu Wenhui , Lai Xinjie , Zhou Qiwei , Zhu Chenbin , Yang Xuelong 
Published: March 2024

Abstract
The annular jet pump is a type of fluid mechanical pump that operates by exchanging momentum with the fluid. Annular jet pumps possess distinctive advantages in the transportation of solid particles. However, the efficiency of these pumps is significantly impacted by both the physical properties of the particles and their initial concentration, thereby limiting their practical applications. In this paper, by combining other scholars’ designs of annular jet pumps, the effects of different physical densities and different initial concentrations of particles on the flow field, pressure and efficiency of an annular jet pump were analysed based on the RNG k-ε turbulence model and the Mixture multiphase flow model. The efficiency of the annular jet pump decreases with a higher particle bulk density. Specifically, at an initial concentration of 20% and a flow ratio (M) of 0.5, the efficiency of the annular jet pump fluctuates as follows: it changes from 28.736% under single-phase flow conditions to 25.011%, 24.369%, 23.637%, 22.950%, and 21.733% as the density of particulate matter increases. The findings of this study offer valuable theoretical insights for the implementation of annular jet pumps in engineering discharge applications.
Visual experimental study on cavitation performance of double-suction centrifugal pump
Authors: Hou Duohua , Li Tongxian , Lu Hongzhong , Yao Zhifeng , Xiao Ruofu , Li Shikang 
Published: March 2024

Abstract
In this paper, the cavitation test results of double-suction centrifugal pump are further “visualized” and verified by using high-speed photography technology to photograph the development process and flow field of impeller inlet cavitation. By optimizing the impeller inlet parameters, the key geometric factors affecting the cavitation performance of the double suction pump were determined. The experimental results show that by optimizing the inlet parameters of the double-suction pump and combining the visualization test verification of cavitation, on the basis of ensuring the wide and efficient efficiency of the double-suction centrifugal pump, the optimization scheme of the experimental design greatly improves its cavitation performance, and provides a new design idea and reference for guiding the development and design of products with high cavitation performance.
Research on the internal pressure pulsation characteristics of reactor coolant pump under non-uniform inflow
Authors: Guo Xi’an , Zhi Yifan , Long Yun , Zhang Mingyu , Qiang Zhuang , Zhu Rongsheng 
Published: March 2024

Abstract
In the third generation of nuclear power technology, the first circuit of the nuclear power plant consists of a steam generator and two vertical reactor coolant pumps (RCPs). The two vertical nuclear pumps are installed upside down at the bottom of the steam generator, resulting in uneven flow at the inlet of the reactor coolant pump due to the special structure of the lower chamber of the steam generator. The RCPs is the sole high-speed rotating machinery in the primary circuit, operating under non-uniform flow conditions for extended periods. The resulting effects on pump performance remain ambiguous. In this study, we focused on the pressure pulsation of the non-uniform flow of a third-generation RCP. To analyze this, we utilized high-precision numerical simulation methods to obtain information regarding the internal pressure pulsation characteristics of the non-uniform inflow. Additionally, we investigated the impact that non-uniform inflow has on the radial force characteristics of the RCP. This study aims to enhance the comprehension of pressure pulsation characteristics in reactor coolant pumps under non-uniform inflows. It will offer valuable insights for research on vibration control in these pumps, and support the development of third-generation nuclear power technology.
Effects of guide vane angle on internal flows and vortex characteristic of reactor coolant pump passage under flow coastdown
Authors: Ye D X , Wen T , Luo Y M , Zhang J Y , Han J M , Deng R 
Published: March 2024

Abstract
In order to explore the effects of guide vane angle on internal flows of reactor coolant pump during flow coastdown, the law of vortex evolution and vortex intensity change in the impeller and guide vanes was analyzed. Based on the second generation vortex identification method: Q criterion, the unsteady evolution law and vortex intensity change of impeller guide vane during flow coastdown were analyzed by numerical simulation. The results show with the flow coastdown, fluctuation law of pressure and velocity in the impeller keeps consistent, while the pressure gradually approaches the outlet pressure and the speed decreases. When the vortex identification’s threshold value is Q=24000 s-2, the vortex area in impeller is small and vortex structure is clear. In a rotation period, the shape and area of vortex structure at the inlet with different guide vane angles are the same. The outlet’s vortex structure is affected by dynamic-static interference, resulting the vortex structure is the same but the vortex area is different. The law of guide vane placement angle changes from “convex-vortex” to “concave -vortex”, and vortex area decreases gradually. In the guide vane, horseshoe vortex is dominant, and structure of blocked vortex and shear layer decreases during flow coastdown.
Spatial distribution of rigid vorticity in pump turbine under turbine mode with different heads
Authors: Yan X T , Kan K , Zheng Y , Chen H X 
Published: March 2024

Abstract
Pump turbines under off-design operating conditions can generate significant vortex structures that cause hydraulic instability in the unit. The aim of this study is to investigate the spatial distribution of large-scale rigid vortex structures in the runner blade channels of a model pump turbine operated under different head conditions with fixed guide vane opening in turbine mode. A new method is proposed that utilizes a relative streamline coordinate system based on mean camber line and provides a unique perspective to quantify the spatial distribution and intensity of various physical variables within the runner blade channels from a novel perspective along the streamwise, circumferential, and spanwise directions. Ultimately, an analysis is conducted on the causes of rigid vortex structures. This paper provides a novel and advanced research technique to analyse unstable flow structures in pump turbines.
A bionic anti-cavitation leading edge for pump-turbine
Authors: Fang Mingkun , Zhang Fangfang , Tao Ran , Liu Weichao , Xiao Ruofu 
Published: March 2024

Abstract
Cavitation is one of the most important technical indicators for assessing reversible pump-turbines. This article describes an anti-cavitation leading edge based on a bionic shape to reduce cavitation. The shape is based on 6 typical fish-like streamlined profiles analyzed in CFD simulations. The flow fields around the profiles were analyzed for different angles of attack to identify the one with the least flow separation and a flat pressure drop. A bionic runner was then built to give an anti-cavitation leading edge. Three-dimensional CFD simulations show that the anti-cavitation leading edge effectively inhibits local flow separation and reduce the pressure drop. Moreover, cavitation tests show that the bionic runner reduces the cavitation inception coefficients. Thus, this design reduces the number of cavitation bubbles and improves the cavitation performance. These results will improve safety and reduce costs and provide a reference for similar hydraulic machinery experiencing.
The effect of damping grid on vortex rope and pressure fluctuation in the draft tube of Francis turbine
Authors: Wang Shanlei , Pang Shujiao , Ding Jiawei , Wang Ming , Chen Zhenmu 
Published: March 2024

Abstract
The pressure fluctuation caused by vortex bands is the main cause of vibration in Francis turbines under off-design conditions. Therefore, adopting effective strategies to affect the vortex rope and suppress the pressure fluctuation caused by the vortex rope is great significance for the stable operation of the Francis turbine. In this study, the damping grid were proposed to optimize the flow state of the fluid in the draft tube, and unsteady numerical simulations were performed to determine their mechanism of action. And a detailed analysis was conducted on the test results to understand the impact of damping grids on the Francis turbine vortex rope. The results show that the pressure fluctuation of draft tube under off-design condition is mainly caused by the low-frequency fluctuation caused by the vortex rope. The damping grid can effectively affect the generation of vortex rope and reduce the low-frequency pressure fluctuation in the Francis turbine.
Study on the optimum design of cross flow water turbines using RSM with weighted least squares method
Authors: Geng Y , Kitahora T , Iio S , Choi Y D , Inagaki M 
Published: March 2024

Abstract
In this study, an optimum design method using the response surface method (RSM) was applied to a cross-flow water turbine in which a circular cavity was installed. The efficiency obtained by CFD analysis was used as the objective function. A quadratic equation for the shape parameters obtained using the weighted least-squares method was used to the response surface. For optimal nozzle design, three shape parameters were used: the runner opening angle, nozzle wall exit angle, and radius of curvature of the nozzle wall. In the weighted least-squares method, the weights of the residual between the efficiency obtained from CFD analysis and the value from the response surface were defined as inversely proportional to the root mean square of the difference between the efficiency of the calculation point from CFD and that at the highest efficiency point, such that more accurate optimal values could be estimated. The shape derived using this optimum method achieved high efficiency.
The influence mechanism of asymmetric distribution characteristics of erosion in the injector of Pelton turbines
Authors: Li Fang , Li Chenxi , Sun Shuaihui 
Published: March 2024

Abstract
To analyze the influence mechanism of asymmetric erosion distribution characteristics in the injector of the Pelton turbine, a detailed analysis of erosion amount and distribution characteristics within different regions of the nozzle and needle is conducted, elucidating the motion and distribution characteristics of sediment particles. The Euler-Lagrange method is used to numerically calculate the flow process of sediment particles with a concentration of 2% and diameters of 0.1mm, 0.5mm, 0.75mm, 1mm, and 2mm in the injector, and the erosion amount is estimated. The results show that the sediment particle diameter significantly influences the symmetry of erosion distribution in the injector. When the diameter gradually increases, the symmetrical phenomenon gradually disappears. Furthermore, the influence of sediment particle diameter on erosion degree within different regions of the injector is inconsistent. With the increase of sediment particle diameter, the average erosion rate of the needle increases. While the average erosion rate in the guide plate area of the nozzle decreases at first and then increases, the nozzle throat is reversed. The guide plate affects the distribution and movement of sediment particles at its end, aggravating the asymmetric erosion phenomenon at the nozzle, especially on the small particle size sediment.
Development and experimental study of a kind of fluidic sprinkler
Authors: Zhu Xingye , Kong Jing , Solangi Farheen , Yu Pengpeng 
Published: March 2024

Abstract
In this paper, a new variety of fluidic sprinkler was introduced and its working principle was presented. An auto-testing system of water distribution was established. The technology using rain-collection as an implement used RS485 assembly line for installation. Angle and frequency of step-by-step are effective driving moment operation of the fluidic sprinkler. The water distribution of fluidic sprinkler types 10 to 50 under relevant operating pressures was pointed out. Experimental results demonstrated that the fluidic sprinklers have complied with the national standards in flow, uniform coefficient, range and so on, which was supposed to be substitute samples for impact sprinkler in the future.
Study on the influence of different structural parameters on the performance of Tesla valve
Authors: Zhang Xinchen , Cao Zhengqing , Fang Kaiyue , Yang Xuelong 
Published: March 2024

Abstract
In this paper, the fluid flow of Tesla valve after the change of three structural parameters, such as diverting Angle, bend outlet width and stages, is analyzed, and their effects on the performance of Tesla valve single channel are studied. The results show that the Di value of the Tesla valve presents an upward trend with the increase of the three parameters, that is, the performance of the single pilot pass is getting better and better, but the improvement of its performance will be limited to a certain extent. When the diverting Angle increases, the pressure drop and energy loss caused by the reverse flow of the fluid will be larger, but if the diverting Angle is too large, the forward flow of the fluid in the Tesla valve will be affected. When the width of the bend outlet increases to a certain size, the fluid flowing into the bend pipe is close to the upper limit, and the single pilot performance of the Tesla valve will not be greatly improved. The increase of multiple Tesla valve stages has an effect on both forward and reverse flow of fluid.
Research on aerodynamic influence of contra-rotating propfan slipstream on propfan engine nacelle inlet
Authors: Zhao Haiyu , Zhou Li , Deng Wenjian , Wang Zhanxue 
Published: March 2024

Abstract
In order to investigate the aerodynamic influence of contra-rotating propfan (CRP) slipstream on propfan engine nacelle, numerical simulation research on the CRP/Nacelle integrated configuration was carried out by using sliding mesh unsteady method. The aerodynamic performance of integrated configuration under different working conditions was studied, and compared with nacelle without CRP. Results show that the total pressure recovery coefficient of inlet port increases due to the work done by CRP. However, as the inhale of the wake vortex, the flow structure inside the inlet becomes more complex because of the mixing of wake vortex and wall separation vortex, which leads to a significant increase of distortion index and loss coefficient. Compared with isolated nacelle, the slipstream causes the total pressure recovery coefficient of inlet port increased by 10.2% and 13.4% under cruise condition and takeoff condition, which is accompanied by the intensification of flow loss and non-uniformity inside the inlet, resulting in a significant increase of the total pressure loss coefficient and total pressure distortion index.
Evaluation of the prototype performance of Wanjiazhai Francis turbine with flow pattern analysis
Authors: Liu Xinjun , Lu Jiahao , Luan Shaoshuai , Song Xijie , Wang Zhengwei , Zhu Di , Tao Ran 
Published: March 2024

Abstract
Multiple Francis turbines are installed in Wanjiazhai water conservancy project to generate electricity, and the operating conditions of the units vary greatly. Because the unit head itself is not high, and the parameters such as head, flow and output vary widely, the operation of the unit becomes very complex. Aiming at this problem, this study predicts and analyzes different typical operating conditions during the operation of the unit, and compares them with the field measured results. The analysis of Prototype unit helps us understand the actual flow state inside the unit and observe the possible complex flow phenomenon. Therefore, the distribution of vortices inside the unit is analyzed in depth, and the flow structures inside the volute, stay vane, guide vane, runner and draft tube are compared to serve the safe and stable operation.