Journal articles: 'Francis-Turbine'

1

Chen, Zhenmu, and Young-Do Choi. "Suppression of cavitation in the draft tube of Francis turbine model by J-Groove." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 9 (October 6, 2018): 3100–3110. http://dx.doi.org/10.1177/0954406218802310.

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Cavitation is recognized as a phenomenon that can cause serious damage to a hydro turbine and can reduce its performance when operating at off-design point. This is an undesired phenomenon, which needs to be improved. In order to suppress the cavitation in the Francis turbine draft tube, a technology with grooved draft tube named J-Groove is introduced in the Francis turbine. The Francis turbine performance and the internal flow characteristic are investigated both with and without J-Groove installation by the experimental method and numerical simulation. Visualization was used to capture the cavitation rope in the Francis turbine draft tube to compare with the computational fluid dynamics analysis result. The results show that the turbine performance both with and without J-Groove installation is quite similar. Regardless of impact on performance of Francis turbine by J-Groove, it suppresses the cavitation vortex rope and pressure fluctuation in the Francis turbine draft tube efficiently.

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Ghimire, A., P. Sapkota, A. Kayastha, B. S. Thapa, Y. D. Choi, and Y. H. Lee. "Experimental Analysis of a Simplified Francis Turbine." IOP Conference Series: Earth and Environmental Science 1037, no. 1 (June 1, 2022): 012014. http://dx.doi.org/10.1088/1755-1315/1037/1/012014.

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Abstract Introduction of Francis turbine in Nepalese micro hydropower project has been considered to uplift the turbine manufacturing ability of the local turbine manufacturers, along with the rejuvenation of the micro hydro sector in Nepal. The Francis turbine used in this study was designed for a Micro hydropower plant in Nepal. The design has been simplified in order to facilitate the local manufacturing of the turbine. The locally manufactured Francis turbine has been tested at Turbine Testing Laboratory under variable rotational speed and discharge. The performance of the Francis turbine has been measured at different operating conditions. The CFD analysis performed on the turbine has also been compared to the results obtained from the experiments. The results of pressure fluctuations, during a transient phenomenon, increase in speed of the runner under no load conditions (runaway), has also been studied under different operating conditions.

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Salehi, Saeed, and Håkan Nilsson. "OpenFOAM for Francis Turbine Transients." OpenFOAM® Journal 1 (November 17, 2021): 47–61. http://dx.doi.org/10.51560/ofj.v1.26.

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The flexibility and fast responsiveness of hydropower systems make them a reliable solution to overcome the intermittency of renewable energy resources and balance the electrical grid. Therefore, investigating the complex flow fields during such operation is essential to increase the reliability and lifetime of future hydropower systems. The current article concerns the utilization of OpenFOAM for the numerical study of Francis turbines during transient load change operations. The details of employed models and numerical schemes are thoroughly explained. The Laplacian smoothing algorithm is applied for the deformation of the guide vane domain. The impact of different mesh diffusivity parameters on both load rejection and acceptance operations is studied. It is shown that general slip boundary conditions cannot be used for slipping points on the guide vane upper and lower surfaces. Instead, different alternatives are introduced and compared. The developed framework is tested on a high-head Francis turbine. Different transient operations are simulated and results are compared to the experimental data. It is shown that OpenFOAM can be employed as a trustworthy CFD solver for numerical investigation of Francis turbines transient operations.

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Obretenov,, V. S. "Modernization of Francis Water Turbine." Journal of the Mechanical Behavior of Materials 11, no. 5 (October 2000): 365–72. http://dx.doi.org/10.1515/jmbm.2000.11.5.365.

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5

Zhang, Si Qing, Guo Hua Ma, Yun Long Zhang, and Dong Wang. "Hydraulic Turbine Blades Modeling Based on Two-Dimensional Wooden Patterns." Advanced Materials Research 860-863 (December 2013): 1521–24. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.1521.

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There are many difficulties to design, processing and research on numerical simulation for Francis turbine because of the complexity of blade shape and the difficulty of solid modeling. Based on two-dimensional wooden patterns of Francis turbine blades, this article aims to complete blades three-dimensional modeling for Francis turbine runner with long and short blades by means of Pro-E software which has powerful 3D modeling function. After comparing three kinds of available methods to generate blade across section which provided by Pro-E, finally completed blades three-dimensional modeling by method of generating across section with point files, established a smooth and accurate three-dimensional model. The method provides an accurate physical model for the numerical simulation of the Francis turbine with long and short blades, as well as provides a feasible approach for hydro-mechanical blades modeling.

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Gat, Shrenik B. "Modal Analysis of Francis Turbine Blade Using Composite Material." International Journal Of Mechanical Engineering And Information Technology 05, no. 04 (April 8, 2017): 1855–60. http://dx.doi.org/10.18535/ijmeit/v5i4.01.

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7

Lama, Ram, Saroj Gautam, Hari Prasad Neopane, Biraj Singh Thapa, Sailesh Chitrakar, and Ole Gunnar Dahlhaug. "Recent developments in the optimization of Francis turbine components for minimizing sediment erosion." IOP Conference Series: Earth and Environmental Science 1037, no. 1 (June 1, 2022): 012009. http://dx.doi.org/10.1088/1755-1315/1037/1/012009.

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Abstract Sediment erosion in hydraulic turbines are severe in case of hydropower plants operating in Himalayan Rivers of Nepal. Francis turbine components are heavily eroded while hard particles as quartz flow along with water through the water conduit in power plant. In Francis turbines, the runner blades where significant portion of hydraulic energy converts in mechanical energy are heavily eroded. This is due to complexity in fluid flow while operated at different operating conditions with sediment contained water. Conventional design of Francis turbines has overlooked on the effects of sediment erosion while considering optimum efficiency at all operating conditions. This paper examines multi-objective optimization of a reference 92 kW model Francis runner for minimizing sediment erosion effects. The model turbine studied in this paper is a scale down model turbine of Jhimruk Hydropower Plant, Nepal that is severely affected by sediment erosion. It was found that sediment erosion was reduced significantly at part load, full load and best efficiency point with improvement in hydraulic performance for model turbine utilizing multi-objective optimization on runner blade design.

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8

LIAO, Weili. "Unsteady Flow Analysis of Francis Turbine." Journal of Mechanical Engineering 45, no. 06 (2009): 134. http://dx.doi.org/10.3901/jme.2009.06.134.

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LUO, Xingqi. "Steady Flow Analysis of Francis Turbine." Journal of Mechanical Engineering 45, no. 04 (2009): 208. http://dx.doi.org/10.3901/jme.2009.04.208.

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Gomes Pereira, João, Loïc Andolfatto, and François Avellan. "Monitoring a Francis turbine operating conditions." Flow Measurement and Instrumentation 63 (October 2018): 37–46. http://dx.doi.org/10.1016/j.flowmeasinst.2018.07.007.

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11

., Ashwani Sharma. "EXPERIMENTAL EVALUATION OF A FRANCIS TURBINE." International Journal of Research in Engineering and Technology 05, no. 03 (March 25, 2016): 522–27. http://dx.doi.org/10.15623/ijret.2016.0503094.

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12

Kawajiri, H., Y. Enomoto, and S. Kurosawa. "Design optimization method for Francis turbine." IOP Conference Series: Earth and Environmental Science 22, no. 1 (March 1, 2014): 012026. http://dx.doi.org/10.1088/1755-1315/22/1/012026.

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13

Wang, Weiyu, Qijuan Chen, Xing Liang, Xuhui Yue, and Jinzhou Dou. "A Novel Multidimensional Frequency Band Energy Ratio Analysis Method for the Pressure Fluctuation of Francis Turbine." Mathematical Problems in Engineering 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/3494785.

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The pressure fluctuation has multiple influence on the steady operation of Francis turbine, and the impact degree varies with the operation condition. In this paper, for the analysis of pressure fluctuation in the Francis turbine, a novel feature extraction method of multidimensional frequency bands energy ratio is proposed based on Hilbert Huang Transform (HHT). Firstly, the pressure fluctuation signal is decomposed into intrinsic mode functions (IMFs) by EEMD. Secondly, the Hilbert marginal spectrum is utilized to analyze the frequency characteristics of IMFs. Then, according to the inner frequency of IMFs, each of them is divided into high, medium, or low frequency band which are constructed based on the frequency characteristic of the pressure fluctuations in the Francis turbine. Afterward, the energy ratio of each frequency band to the original signal is calculated, which is to realize the feature extraction of multidimensional frequency band energy ratio. Actual applications verify that this method not only can extract the time-frequency characteristics but also can analyze the condition feature of the pressure fluctuation. It is a novel method for extracting the feature of pressure fluctuation in the Francis turbine.

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14

Ji, Lei, Lianchen Xu, Yuanjie Peng, Xiaoyi Zhao, Zhen Li, Wen Tang, Demin Liu, and Xiaobing Liu. "Experimental and Numerical Simulation Study on the Flow Characteristics of the Draft Tube in Francis Turbine." Machines 10, no. 4 (March 25, 2022): 230. http://dx.doi.org/10.3390/machines10040230.

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The flow characteristics of the draft tube of a Francis turbine have a significant influence on turbine stability. Numerical simulations were performed for a Francis turbine under three different output conditions of 20%, 100%, and 120% at the rated and maximum heads. Laser Doppler velocimetry (LDV) tests were conducted to test the flow characteristics of the draft tube of the Francis turbine model. The flow characteristics in the draft tube, the mechanism of the flow characteristics change, and the effect of the opening on the vortex rope were analyzed. The results showed that the large and invisible vortex in the conical cross-section at the inlet of the draft tube gradually changed to a tangible vortex rope as the guide vane opening (GVO) increased. The pressure and velocity are significantly influenced by the GVO, and the flow characteristics in the draft tube improve as the GVO increases. Simultaneously, the influence range of the vortex rope increased as the head increased.

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Hu, Ying, and Kun Wang. "Three-Dimensional Unsteady Simulation in a Water Turbine." Advanced Materials Research 655-657 (January 2013): 227–30. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.227.

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This paper introduces the 3D numerical simulation of unsteady turbulent flow in the entire flow passage of a water turbine model with CFD technology. A new and available method for the design of a Francis turbine has been explored. The boundary conditions have been implemented based on the 3D averaged N-S equations. The governing equations are discreted on space by the finite volume method and on time step by the finite difference method. The 3D unsteady turbulent flow in an entire Francis turbine model is calculated successfully using the CFX-TASCflow software and RNG k-εturbulence model. Transient flow fields are simulated in the spiral case, the distributor, the runner and the draft tube. It is presented in this paper that the computer simulation of the flow fields in components of the Francis turbine at the optimum operating condition. Meanwhile, the velocity and pressure at any points in the flow fields can be obtained so as to provide the great value on the performance prediction. According to the simulating results, the flow analysis and the design experience, the design of components in a Francis turbine model can be improved and optimized. In this way, designers may decrease numbers of test and shorten the period for a model. Therefore, the cost of research and produce can be reduced.

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Xu, Lianchen, Xiaohui Jin, Zhen Li, Wanquan Deng, Demin Liu, and Xiaobing Liu. "Particle Image Velocimetry Test for the Inter-Blade Vortex in a Francis Turbine." Processes 9, no. 11 (November 4, 2021): 1968. http://dx.doi.org/10.3390/pr9111968.

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Hydropower units are usually operated in non-design conditions because of power grid requirements. In a partial-load condition, an inter-blade vortex phenomenon occurs between the runner blades of a Francis turbine, causing pressure pulsation and unit vibration, which hinder the safe and stable operation of power stations. However, the mechanism through which the inter-blade vortex generation occurs is not entirely clear. In this study, a specific model of the Francis turbine was used to investigate and visually observe the generation of the blade vortex in Francis turbines in both the initial inter-blade and vortex development zones. Particle image velocimetry was used for this purpose. In addition, we determined the variation law of the inter-blade vortex in the Francis turbine. We found that the size and strength of the inter-blade vortex depend on the unit speed of the turbine. The higher the unit speed is, the stronger the inter-blade vortex becomes. We concluded that the inter-blade vortex of such turbines originates from the pressure surface or secondary flow and stall of the blade at the inlet side of the runner at high unit speeds, and also from the backflow zone of the suction surface of the blade at low unit speeds.

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Umar, Baig Mirza, Jingwei Cao, and Zhengwei Wang. "EXPERIMENTAL AND CFD SIMULATION VALIDATION PERFORMANCE ANALYSIS OF FRANCIS TURBINE." IOP Conference Series: Earth and Environmental Science 1037, no. 1 (June 1, 2022): 012003. http://dx.doi.org/10.1088/1755-1315/1037/1/012003.

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Abstract Francis Turbines are designed to Extract hydraulic power as much as possible in hydro power plant stations. Performance analysis and selecting design of hydraulic turbines are two very essential aspects of any hydro power project which ensure the economical and efficient functioning of these hydro power plants.CFD simulation can provide us insight into field flow characteristics which will help us understand the design parameter and development of Francis turbine. The performance analyzed in different operating conditions with the help of numerical simulation and experimental testing. The various visualization techniques in numerically and Physically model testing for hydraulic performance with maximum-minimum and rated head and different flow rate analyses of the turbines are briefly discussed. These techniques can be provided efficiency and insight flow characteristics with different operating conditions of the Francis turbine. Efficiency is calculated 94% with Computational fluid dynamics simulation with an error of less than 0.7% compared with physical model testing. The numerically simulation and physical model testing are shown that feasibility for the optimal design of the hydraulic Francis turbine.

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Lu, Lei, Li Da Zhang, Jing Yang, Long Zhou, and Zhi Jian Xu. "Cause Research about Vibration and Noise Caused by Channel Vortices at High Load in Francis Turbine." Advanced Materials Research 860-863 (December 2013): 1569–73. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.1569.

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A low head hydropower station is in the southwest of China, its Francis turbine ran well at a rated power and rated net head, but the turbine produced severe abnormal vibration and noise at higher head than the rated head, full load and overload. By analyzing, characteristic points on vibration conditions are inside the area of channel vortices on runner performance curve. CFD analysis indicates that unstable vortices exist between runner blades. The two results demonstrate that the vibration and noise of Francis turbine are caused by runner channel vortices at higher head than the rated head, full load and overload.

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Lama, R., S. Gautam, L. Lama, H. P. Neopane, and S. Chitrakar. "Development of a test rig for investigating the performance of a model Francis turbine." IOP Conference Series: Earth and Environmental Science 1079, no. 1 (September 1, 2022): 012011. http://dx.doi.org/10.1088/1755-1315/1079/1/012011.

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Abstract Sediments flowing with water in the Himalayan Rivers of Nepal erodes the components of the turbine heavily. The design of hydraulic turbines prioritizes the hydraulic performance of the turbine, neglecting erosion challenges. The necessity of turbine design and its model testing has been felt in the past two decades in Nepal. An attempt is made to fill such conditions by developing a test rig for testing the 92 kW model Francis turbine at Turbine Testing Lab, Kathmandu University, Nepal. The model turbine is a scaled-down model of a 4.1 MW Francis turbine of a Jhimruk Hydropower Plant in Nepal severely affected by sediment erosion. The design of the prototype turbine was carried out considering the hydraulic performance as well as erosion resistivity. The prototype turbine was scaled-down utilising model similarity conditions to meet the lab’s specifications. Each component of the rig has been optimized using CFD to match the lab’s specifications. Comparing the results from CFD and experiment on velocity, pressure, torque, and RPM measurements were comparable.

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Zhao, Dao Li, Wu Ke Liang, Hai Peng Nan, Wei Ma, Jin Bo Li, and Tao Tao Li. "Influences of Clearance in the Nether Wearing Ring on the Self-Excited Vibration of the Francis Turbine." Advanced Materials Research 383-390 (November 2011): 1150–54. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.1150.

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Aimed at the self-excited vibration of caused by unreasonable clearance in wearing ring of the Francis turbine, whole flow passage of prototype hydraulic turbine which contains the clearance in wearing ring is numerically calculated by computational fluid dynamics software CFX based on N-S equation and RNG k-turbulence model. The result shows that the flow field in front of inlet of runner is unstable extremely, even if a tiny disturbance effects on, which will be out-of-balance symmetrically in the radial direction, then the force of runner will be unbalance, which will cause vibration of the hydraulic turbine. As well as, a reasonable clearance in wearing ring of the Francis turbine will reduce the impact of the water in the inlet of the clearance, and self-excited vibration of the hydraulic turbine will eliminate.

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21

Gordon, J. L. "Hydraulic turbine efficiency." Canadian Journal of Civil Engineering 28, no. 2 (April 1, 2001): 238–53. http://dx.doi.org/10.1139/l00-102.

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A set of empirical equations has been developed which defines the peak efficiency and shape of the efficiency curve for hydraulic turbines as a function of the commissioning date for the unit, rated head, rated flow, runner speed, and runner throat or impulse turbine jet diameter. The equations are based on an analysis of peak efficiency data from 56 Francis, 33 axial-flow, and eight impulse runners dating from 1908 to the present, with runner diameters ranging from just under 0.6 m to almost 9.5 m. The metric specific speeds (nq) ranged from 5.3 to 294. The root mean square error of the calculated peak efficiency for Francis and axial-flow runners was found to be 0.65%. The shape of the efficiency curves was derived from eight Francis, five Kaplan, three propeller, and four impulse turbines. Charts showing the relationship between calculated and actual efficiency curves for these 20 runners are provided. A good match between calculated and measured or guaranteed efficiency was obtained. The equations were also used to determine the relative increase in peak efficiency for new reaction runners installed in existing casings at 22 powerplants, with a root mean square accuracy of 1.0%. The equations can be used to (i) develop efficiency curves for new and old runners; (ii) compare the energy output of alternative types of turbines, where this choice is available; and (iii) calculate the approximate incremental energy benefit from installing a new runner in an existing reaction turbine casing, or onto the shaft of an impulse unit.Key words: hydraulic turbines, turbine renovation, turbine efficiency.

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Vashishtha, Govind, and Rajesh Kumar. "Autocorrelation energy and aquila optimizer for MED filtering of sound signal to detect bearing defect in Francis turbine." Measurement Science and Technology 33, no. 1 (October 20, 2021): 015006. http://dx.doi.org/10.1088/1361-6501/ac2cf2.

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Abstract This paper presents a method to detect the bearing defects in Francis turbine by minimal entropy deconvolution (MED) filter making use of a sound signal. As the outputs of MED are mainly influenced by the filter length hence its appropriate selection is very necessary to recover a single random pulse in case of a weak faulty signal. The optimal filter length selection is done by Aquila optimizer adaptively which uses the autocorrelation energy as its fitness function. Experimentation done on defective bearings of Francis turbine suggested that the proposed method exposes periodic impulses effectively in case of a weak faulty signal or when the fault signal is embedded within the noise or interferences from other parts of Francis turbine. The proposed fault identification method has been compared with other models of MED such as particle swarm optimization -MED and maximum correlated kurtosis deconvolution. Results obtained reveals that the proposed method is superior in identifying the faulty signal embedded with heavy noise.

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Khare, Ruchi, and Vishnu Prasad. "Numerical Study on Performance Characteristics of Draft Tube of Mixed Flow Hydraulic Turbine." Hydro Nepal: Journal of Water, Energy and Environment 10 (December 5, 2012): 48–52. http://dx.doi.org/10.3126/hn.v10i0.7103.

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Draft tube is an important component of the hydraulic reaction turbine and affects the overall performance of turbine to a large extent. The flow inside the draft tube is complex because of the whirling flow coming out of runner and its diffusion along the draft tube. The kinetic energy coming out of runner is recovered in draft tube and part of recovery meets the losses. In the present work, the computational fluid dynamics (CFD) has been used for flow simulation in complete mixed flow Francis turbine for performance analysis for energy recovery, losses and flow pattern in an elbow draft tube used in Francis turbine at different operating conditions. The overall performance of the turbine at some typical operating regimes is validated with the experimental results and found to be in close comparison.DOI: http://dx.doi.org/10.3126/hn.v10i0.7103 Hydro Nepal Vol.10 January 2012 48-52

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Tengs, E., F. Charrassier, M. Jordal, and I. Iliev. "Multidisciplinary optimization of a Francis turbine runner." IOP Conference Series: Earth and Environmental Science 1079, no. 1 (September 1, 2022): 012077. http://dx.doi.org/10.1088/1755-1315/1079/1/012077.

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Abstract A fully automated multi-disciplinary design optimization procedure for a Francis turbine runner has been developed in a previous task of the Horizon2020-HydroFlex project. The design optimization was limited to blade design, with the goal of improving the hydraulic efficiency and torque, and reducing the harmonic structural stresses. This is to ensure that the turbine is less prone to fatigue, but still performs well hydraulically. Results from the numerical optimization are presented in this paper. From the design optimization, two runner designs are highlighted. One that performs significantly better than a reference design, and one that performs significantly worse. It is observed that small, but significant improvements can be obtained in both torque and efficiency, while at the same time reducing the structural stresses drastically. This shows that there might be previously unknown areas in the design space that can be explored, especially on the structural side.

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Twayna, Ranjeet, Ram Manandhar, Bikash Singh, Dadiram Dahal, Atmaram Kayastha, and Biraj Singh Thapa. "Numerical investigation of Cavitation in Francis Turbine." IOP Conference Series: Earth and Environmental Science 1037, no. 1 (June 1, 2022): 012017. http://dx.doi.org/10.1088/1755-1315/1037/1/012017.

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Abstract Cavitation is one of the major challenges in the Himalayan rivers of Nepal that cause damage and degradation of the performance of hydraulic turbine components. Numerical analysis has been performed to investigate the cavitation effect in the Francis turbine. For detection of cavitation, the SST turbulence model using Rayleigh plesset equation has been used in ANSYS-CFX. The turbine is investigated for three different operating conditions i.e. part load, BEP and full load under cavitation and without cavitation. The results are shown based on efficiency, pressure fluctuation, vortex rope and vapor volume fraction. It has been observed that changes in efficiency and pressure distribution are found to be minimal between cavitation and without cavitation conditions at rated discharge and head. Under part load condition, turbine efficiency loss and vapor bubbles formation at the leading edge of the runner blade is found to be maximum.

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Żółtowski, Mariusz, Bogdan Żółtowski, and Leonel Castaneda. "Study of the state a Francis turbine." Polish Maritime Research 20, no. 2 (April 1, 2013): 41–47. http://dx.doi.org/10.2478/pomr-2013-0015.

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Abstract This paper presents a methodology to evaluate the technical state of a Francis turbine by shaft rotor dynamic simulation. There are several rotor dynamic criteria that define the technical state of a turbo-machine. To feed the shaft rotor dynamic model this delivers the required information to accomplish the technical assessment. The numerical rotor dynamic model uses as input, the field forces obtained by the fluid-solid interaction analysis undertaken over the blades of the runner. The rotor dynamic numerical simulations allow to determinate the record-in-time of the displacements of any point along the shaft. This information is relevant for diagnosis tasks, because it is possible to decompose it spectrally and to estimate the severity of the vibrations. Comparing the results of the numerical model against those obtained from machines that operates under normal conditions, it is possible to determinate the technical state of the turbo-machine. This allows studying the stability of the turbine working on several operation ranges. A Francis turbine is a very complex machine that involves many physical phenomena of different nature. In this way, the hydraulic input forces needed by the rotor dynamic model should not be assumed but calculated directly from the fluid interaction over the turbine structure.

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Djodikusumo, Indra, Koko Suherman, and Paskalis Bowo A. Oken. "Tolerance Stack Analysis in Francis Turbine Design." ITB Journal of Engineering Science 42, no. 1 (2010): 73–90. http://dx.doi.org/10.5614/itbj.eng.sci.2010.42.1.6.

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Han, Fengqin, Takashi Kubota, and Yuji Nakanishi. "Draft Tube Performance of GAMM Francis Turbine." Transactions of the Japan Society of Mechanical Engineers Series B 61, no. 591 (1995): 3921–26. http://dx.doi.org/10.1299/kikaib.61.3921.

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Wang, Y. L., G. Y. Li, Q. H. Shi, and Z. N. Wang. "Hydraulic design development of Xiluodu Francis turbine." IOP Conference Series: Earth and Environmental Science 15, no. 3 (November 26, 2012): 032006. http://dx.doi.org/10.1088/1755-1315/15/3/032006.

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Shanab, Belal H., M. Elfaisal Elrefaie, and Ayman Ali El-Badawy. "Active control of variable geometry Francis Turbine." Renewable Energy 145 (January 2020): 1080–90. http://dx.doi.org/10.1016/j.renene.2019.05.125.

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Pochylý, František, Miloslav Haluza, and Jindřich Veselý. "The Francis Pump Turbine With Stochastic Blades." Procedia Engineering 39 (2012): 68–75. http://dx.doi.org/10.1016/j.proeng.2012.07.009.

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Kurosawa, S., S. M. Lim, and Y. Enomoto. "Virtual model test for a Francis turbine." IOP Conference Series: Earth and Environmental Science 12 (August 1, 2010): 012063. http://dx.doi.org/10.1088/1755-1315/12/1/012063.

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Frunzǎverde, D., S. Muntean, G. Mǎrginean, V. Câmpian, L. Marşavina, R. Terzi, and V. Şerban. "Failure analysis of a Francis turbine runner." IOP Conference Series: Earth and Environmental Science 12 (August 1, 2010): 012115. http://dx.doi.org/10.1088/1755-1315/12/1/012115.

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Diyorov, Rustam Kh, and M. V. Glazyrin. "Francis Turbine Modeling for Hydrounit on the Bases of the Doubly Fed Induction Machine." Applied Mechanics and Materials 792 (September 2015): 203–8. http://dx.doi.org/10.4028/www.scientific.net/amm.792.203.

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The mathematical model of Francis turbine, operating at variable speed hydrounit, has created. The results of numerical modeling are fully consistent with the physical representation of the behavior of the hydraulic turbine in dynamic modes.

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He, Fang. "Based on CFX Numerical Simulation of Francis Turbine Runner." Applied Mechanics and Materials 456 (October 2013): 207–10. http://dx.doi.org/10.4028/www.scientific.net/amm.456.207.

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This paper presents a vibration prediction method for Francis turbine: Provided with advanced CFX software, Numerical simulation of movable guide vane and Turbine runner’s internal flow state. From the source of hydraulic vibration, Focus on numerical analysis, numerical simulation for the cutting thickness of the runner blade. After analysis of the influence of the blade of hydraulic vibration. To explore new ways for the hydro turbine control hydraulic vibration.

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Zhang, Si Qing, Guo Hua Ma, and Jing Qian. "Numerical Simulation of Cavitation Flow Field in a Francis Turbine Runner with Attached Blades." Applied Mechanics and Materials 700 (December 2014): 637–42. http://dx.doi.org/10.4028/www.scientific.net/amm.700.637.

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The numerical simulation of cavitation flow field in a Francis turbine runner with attached blades was conducted based on the no-slip mixture model in the Euler approach and the Singhal cavitation model. The RNG model after correcting viscosity and the pressure correction algorithm (SIMPLE) were supplemented. The distributions of the water-vapor volume fraction under non-design conditions were obtained. The results show that the method based on two-phase mixture model can be used to simulate the position and degree of cavitation flow in Francis turbine.

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Zhang, Dun, Yuan Zheng, Ying Zhao, and Jian Jun Huang. "The Characteristics Research of Tube Vortex Based on Large Eddy Simulation." Applied Mechanics and Materials 121-126 (October 2011): 3657–61. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.3657.

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Numerical simulation of three-dimensional transient turbulent flow in the whole flow passage of a Francis turbine were based upon the large eddy simulation(LES) technique on Smargorinsky model and sliding mesh technology. The steady flow data simulated with the standard k-εmodel was used as the initial conditions for the unsteady simulation. The results show that LES can do well transient turbulent flow simulation in a Francis turbine with complex geometry. The computational method provides some reference for exploring the mechanism of eddy formation in a complex turbulent of hydraulic machinery.

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Li, Z. J., X. J. Yang, G. W. Cai, and X. S. Liu. "Frequency Reliability Analysis of Francis Turbine-Generator Units Based on Nonlinear Vibration." Materials Science Forum 628-629 (August 2009): 233–38. http://dx.doi.org/10.4028/www.scientific.net/msf.628-629.233.

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This paper studies the frequency reliability of the main shaft system of Francis turbine-generator units based on nonlinear vibration. Taking the generator and turbine as an integrated system, the nonlinear coupling dynamic equations of the system are established by the finite element method. According to the dynamic equations, the frequent factors of system are obtained by the method of multiple scales. The criterion is used that the difference between the natural frequencies and driving frequencies including the frequent factors should be less than specific values. The reliability mode and the safety probability of the main shaft system of Francis turbine-generator units are defined as a series mode, and the frequency reliability analysis method for avoiding the resonance is proposed. Finally, an example is presented.

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Saeed, Raza Abdulla. "Analysis of Fatigue Failure of Francis Turbine Runner at Derbendikhan Hydropower Station." Sulaimani Journal for Engineering Sciences 4, no. 4 (May 1, 2017): 7–13. http://dx.doi.org/10.17656/sjes.10042.

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Koirala, Ravi, Sailesh Chitrakar, Amod Panthee, Hari Prasad Neopane, and Bhola Thapa. "Implementation of Computer Aided Engineering for Francis Turbine Development in Nepal." International Journal of Manufacturing Engineering 2015 (August 13, 2015): 1–9. http://dx.doi.org/10.1155/2015/509808.

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The expansion of the existing industries involved in the production of components of hydropower to the Francis turbine manufacturer up to 5 MW unit size has been recognized as one of the most promising business models in Nepal. Given the current fact that the development of Francis turbines with the manufacturers of Nepal has not been done yet, due to lack of designing expertise and limitations in the available technology, this paper presents the use of different available manufacturing technologies, which is suitable in the Nepalese hydropower market. This is an experience based paper, in which the advanced manufacturing process implementing Computer Aided Simulation (CAS), Computer Aided Design (CAD), and Computer Aided Manufacturing (CAM) is introduced for turbine manufacturing. Moreover, CAD from Solidworks, 3D printing from Rapid Prototyping Machine (RPM), and manufacturing of three designs by three different methods, dye casting, lost wax casting, and forging in a local workshop, have been described. The outcome of this work is the identification of suitable Francis turbine development methodologies in context of Nepal, incorporating industrial revolution through research based products.

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Zhu, WenRuo, ZhongXin Gao, YongJun Tang, JianGuang Zhang, and Li Lu. "Adaptability of turbulence models to predict the performance and blade surface pressure prediction of a Francis turbine." Engineering Computations 33, no. 1 (March 7, 2016): 238–51. http://dx.doi.org/10.1108/ec-06-2014-0137.

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Purpose – The purpose of this paper is to analyze the ability of turbulence models to model the flow field in the runner of a Francis turbine. Although the complex flow in the turbine can be simulated by CFD models, the prediction accuracy still needs to be improved. The choice of the turbulence model is one key tool that affects the prediction accuracy of numerical simulations. Design/methodology/approach – This study used the SST k-w and RNG k-e turbulence models, which can both accurately predict complex flow fields in numerical simulations, to simulate the flow in the entire flow passage of a Francis turbine with the results compared against experimental data for the performance and blade pressure distribution in the turbine to evaluate the applicability of the turbulence models. Findings – The results show that the SST k-w turbulence model more accurately predicts the turbine performance than the RNG turbulence model. However, the blade surface pressures predicted by the SST k-w turbulence model were basically identical to those predicted by the RNG k-e turbulence model, with both accurately predicting the experimental data. Research limitations/implications – Due to the lack of space, the method used to measure the blade surface pressure distributions is not introduced in this paper. Practical implications – Turbine performance and flow field pressure in the runner, which are the basis of turbine preliminary performance judgment and optimization through CFD, can be used to judge the rationality of the turbine runner design. The paper provides an evidence for the turbulence selection in numerical simulation to predict turbine performance and flow field pressure in the runner and improves the CFD prediction accuracy. Originality/value – This paper fulfils a test of the flow field pressure in the runner, which provide an evidence for judge the adaptability of turbulence model on the flow field in runner. And this paper also provides important evaluations of two turbulence models for modeling the flow field pressure distribution in the runner of a Francis turbine to improve the accuracy of CFD models for predicting turbine performance.

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Mössinger, Peter, Roland Jester-Zürker, and Alexander Jung. "Francis-99: Transient CFD simulation of load changes and turbine shutdown in a model sized high-head Francis turbine." Journal of Physics: Conference Series 782 (January 2017): 012001. http://dx.doi.org/10.1088/1742-6596/782/1/012001.

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43

Libor, Koudelka. "Do not be Afraid of Small High-Speed Francis Turbines." Strojnícky casopis – Journal of Mechanical Engineering 68, no. 3 (November 1, 2018): 111–28. http://dx.doi.org/10.2478/scjme-2018-0030.

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AbstractIn the first quarter of the last century hydraulic power plants were equipped with high-speed Francis turbines even in the situation when a contemporary project manager would suggest Kaplan turbine. The reason is simple. Mr. Kaplan patented his turbine only in 1912 [1], https://en.wikipedia.org/wiki/Viktor_Kaplan . Those high-speed Francis turbines have just reached their lifetime. Mainly runners need repair. Our customers’ respond is that even renowned firms refuse to deliver runners with better parameters. Offer is to replace whole turbine with Kaplan or to make a copy of the existing runner. This paper presents experience and results of such a high-speed runner design. The runner substituted the one of Prokopa & sons from 1939 in powerhouse and mill at Křemže stream. Virtual prototyping technique has been used.

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Zhang, Lan Jin, Lei Wang, and Yan Ren. "Characteristic Analysis of Francis-Turbine in Cooling Tower." Applied Mechanics and Materials 190-191 (July 2012): 57–59. http://dx.doi.org/10.4028/www.scientific.net/amm.190-191.57.

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The water turbine stands in the cooling water system and drives the fan in the cooling tower, so its flow rate, head and output is limited to the flow rate of cooling water, saved-energy of pump and input of fan separately. The spiral casing dimension of water turbine is limited to the diameter of tower. All above facts make the water turbine of cooling tower be different to that of water power station. The paper introduces one turbine which flow rate is 0.139m/s. Its characteristic of flow passage and hydraulic performance is analyzed, and some new flow passage to improve hydraulic performance is suggested.

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Drtina, P., and M. Sallaberger. "Hydraulic turbines—basic principles and state-of-the-art computational fluid dynamics applications." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 213, no. 1 (January 1, 1999): 85–102. http://dx.doi.org/10.1243/0954406991522202.

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The present paper discusses the basic principles of hydraulic turbines, with special emphasis on the use of computational fluid dynamics (CFD) as a tool which is being increasingly applied to gain insight into the complex three-dimensional (3D) phenomena occurring in these types of fluid machinery. The basic fluid mechanics is briefly treated for the three main types of hydraulic turbine: Pelton, Francis and axial turbines. From the vast number of applications where CFD has proven to be an important help to the design engineer, two examples have been chosen for a detailed discussion. The first example gives a comparison of experimental data and 3D Euler and 3D Navier-Stokes results for the flow in a Francis runner. The second example highlights the state-of-the-art of predicting the performance of an entire Francis turbine by means of numerical simulation.

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Cha, Sanghoon, Jongwoong Choi, and Sungho Ko. "Performance Prediction of Hydraulic Model Turbine for On-site Francis Turbine Development." KSFM Journal of Fluid Machinery 20, no. 4 (August 31, 2017): 5–11. http://dx.doi.org/10.5293/kfma.2017.20.4.005.

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Ji, Shu De, Xue Song Liu, Jian Guo Yang, and Zhen Lei Liu. "Virtual Optimization of Regulating and Controlling on Welding Residual Stress of Francis Turbine Runner." Materials Science Forum 704-705 (December 2011): 762–69. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.762.

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In order to solve the problem of crack appeared in Francis turbine runner, the welding residual stress of Francis turbine runner is regulated and controlled by means of numerical simulation from the view of subsection welding, local heating and local peening. The results show that the length of welding section of blade outlet and the welding direction in the subsection welding process influence the residual stress of the turbine blade. For the local heating technology, the decreasing effect on residual stress increases with the increase of heating time, heating temperature and heating area. The welding residual stress of dangerous region decreases and then increases with the increase of heating distance. Moreover, the peening effect is very clear when the temperature of material in the peening region reaches its own plastic temperature.

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Wu, Lei, Yan Chao Yin, Zhuang Xiong, and Yi Long Yan. "Research on Cutting Force Simulation for Francis Hydro Turbine’s Blade Based on VERICUT." Advanced Materials Research 889-890 (February 2014): 78–81. http://dx.doi.org/10.4028/www.scientific.net/amr.889-890.78.

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Hydro turbine blade is a very complex body closed by sculptured surface, and reasonable cutting parameters are very important for the quality of Francis Hydro Turbine blades and machining efficiency. An implementation method of digital cutting force simulation was proposed in this paper for Francis Hydro Turbines Blade based on VERICUT. Firstly ,cutting parameters can be extracted by the secondary development of VERICUT, and the forecasting process of cutting force have been established under the different parameters in theVERICUT. Then we can obtain the change of cutting force by adjusting cutting parameters in the process of digital machining simulation, and the influence of cutting parameter on cutting force was analyzed. Finally, the case study on the Hydro turbine blade has been conducted, and its application results are remarkable.

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Wang, Xiang Hong, Hong Wei Hu, Yi Min Shao, and Jun Qing Fu. "The Distance Attenuation of Acoustic Emission Signals in Turbine Runners." Applied Mechanics and Materials 103 (September 2011): 262–67. http://dx.doi.org/10.4028/www.scientific.net/amm.103.262.

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Initiation of blade cracks in Francis turbine runners endangers the safety operation of power stations, so it is crucial to detect the cracks before emergencies happen. This article is a preliminary study of applying acoustic emission (AE) technique to detecting the large-scale turbine runners. A series of experiments had been carried out on an HLA286a-LJ-800 Francis turbine runner. The attenuation characteristics due to propagation distance were studied. From the tests, it is concluded that AE signals are detectable after propagating at a distance of 6 m. The propagation distance is the major factor of attenuation. As a result, although attenuation is incurred, it is feasible to apply AE technique to monitoring crack signals in runners. However, it depends on the understanding of background noise and extraction of right signals.

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Kurir, Valerij. "Optimization the shape of the Francis hydraulic turbine." E3S Web of Conferences 220 (2020): 01067. http://dx.doi.org/10.1051/e3sconf/202022001067.

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The article presents one of the possible methods for optimizing the blade shape of a Francis radial-axial hydraulic turbine. The method for optimizing the shape of the turbine blade is based on the criterion of the maximum mechanical moment developed by the turbine. The blade shape optimization operation is conventionally divided into two stages. At the first stage of optimization of the blade shape, the analytical expression of the moment developed by the turbine is presented in a Taylor series by variable parameters − the coordinates of the vertices of the characteristic polyhedron of the median surface of the turbine blade. Adding the boundary conditions in the formulation of the optimization problem in the form of equalities − the contact of the median surface of the turbine blade with the turbine hub and rim, as well as conditions in the form of inequalities − the concavity of the greater part the median surface allows to reduce the problem of optimizing the blade shape to a standard linear programming problem. It is proposed to carry out 50−60 similar operations with small steps in the variables − the coordinates of the vertices of the characteristic polyhedron. Thus, it is necessary to move into the zone of optimal values of the coordinates of the vertices of the characteristic polyhedron of the median surface of the blade. At the second stage, it is proposed to continue the search for the optimal values of the coordinates of the vertices of the characteristic polyhedron of the median surface of the blade, applying for this purpose one of the most effective algorithms of genetic optimization.

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Journal articles on the topic 'Francis-Turbine'

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