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Records with Subject: Modelling and Simulations
Showing records 1 to 25 of 165. [First] Page: 1 2 3 4 5 Last
Experimental Investigation on a Thermal Model for a Basin Solar Still with an External Reflector
Masoud Afrand, Rasool Kalbasi, Arash Karimipour, Somchai Wongwises
March 15, 2019 (v1)
Keywords: basin solar still, desalination, external reflector, still efficiency, thermal model
In this study, a thermal model for estimating the efficiency of a basin solar still with an external reflector was introduced using the energy balance equations of different parts of the solar still. Then, in order to verify the precision and accuracy of this model, a basin solar still with an external reflector was constructed and some experiments were performed. The hourly temperature values for different places of the still and amount of distilled water were calculated using the thermal model and compared with experimental measurements. Comparisons show that the thermal model of the still is in good agreement with the experimental results. Therefore, it can be concluded that the introduced thermal model can be used reliably to estimate the amount of distilled water and efficiency of the basin solar still with an external reflector. Results also revealed that the efficiency of the solar still is low in the early hours, while it was enhanced 44% in the afternoon. Furthermore, it was c... [more]
Improved Battery Parameter Estimation Method Considering Operating Scenarios for HEV/EV Applications
Jufeng Yang, Bing Xia, Yunlong Shang, Wenxin Huang, Chris Mi
March 15, 2019 (v1)
Keywords: equivalent circuit modeling, lithium-ion battery, operating scenario, parameter estimation
This paper presents an improved battery parameter estimation method based on typical operating scenarios in hybrid electric vehicles and pure electric vehicles. Compared with the conventional estimation methods, the proposed method takes both the constant-current charging and the dynamic driving scenarios into account, and two separate sets of model parameters are estimated through different parts of the pulse-rest test. The model parameters for the constant-charging scenario are estimated from the data in the pulse-charging periods, while the model parameters for the dynamic driving scenario are estimated from the data in the rest periods, and the length of the fitted dataset is determined by the spectrum analysis of the load current. In addition, the unsaturated phenomenon caused by the long-term resistor-capacitor (RC) network is analyzed, and the initial voltage expressions of the RC networks in the fitting functions are improved to ensure a higher model fidelity. Simulation and ex... [more]
Performance of a Predictive Model for Calculating Ascent Time to a Target Temperature
Jin Woo Moon, Min Hee Chung, Hayub Song, Se-Young Lee
February 27, 2019 (v1)
Keywords: artificial neural network (ANN), ascending time, heating system, predictive controls, setback temperature
The aim of this study was to develop an artificial neural network (ANN) prediction model for controlling building heating systems. This model was used to calculate the ascent time of indoor temperature from the setback period (when a building was not occupied) to a target setpoint temperature (when a building was occupied). The calculated ascent time was applied to determine the proper moment to start increasing the temperature from the setback temperature to reach the target temperature at an appropriate time. Three major steps were conducted: (1) model development; (2) model optimization; and (3) performance evaluation. Two software programs—Matrix Laboratory (MATLAB) and Transient Systems Simulation (TRNSYS)—were used for model development, performance tests, and numerical simulation methods. Correlation analysis between input variables and the output variable of the ANN model revealed that two input variables (current indoor air temperature and temperature difference from the targe... [more]
Modeling of a Field-Modulated Permanent-Magnet Machine
Xianglin Li, K. T. Chau, Yubin Wang
February 27, 2019 (v1)
Keywords: d-q frame, field-modulated permanent magnet (FMPM) machine, finite element analysis (FEA), Modelling
In this work, an effective field-modulated permanent-magnet (FMPM) machine was investigated, in which the spoke-magnet outer rotor and open-slot stator were employed. The objective of this paper is to provide the mathematical modeling analysis that was performed for the purpose of control research on this type of FMPM machine. The simulation results by means of finite element analysis (FEA) are given to verify the theoretical analysis and the validity of mathematical model. A prototype machine was also fabricated for experimentation. Both the analytical model and the FEA results are validated by experimental tests on the prototype machine.
Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft
Yuji Ohya, Masaki Wataka, Koichi Watanabe, Takanori Uchida
February 27, 2019 (v1)
Keywords: computational fluid dynamics (CFD), diffuser, laboratory experiment, solar tower, thermal updraft
A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward the center. Attached to the center of the inside of the collector is a vertical tower within which a wind turbine is mounted at the lower entry to the tower. When solar radiation heats the ground through the glass roof, ascending warm air is guided to the center and into the tower. A solar tower that can generate electricity using a simple structure that enables easy and less costly maintenance has considerable advantages. However, conversion efficiency from sunshine energy to mechanical turbine energy is very low. Aiming to improve this efficiency, the research project developed a diffuser-type tower instead of a cylindrical tower, and investigated a suitable diffuser shape for practical use. After changing the tower height and diffuser open angle, w... [more]
Numerical Simulation of a Vortex Combustor Based on Aluminum and Steam
Xianhe Chen, Zhixun Xia, Liya Huang, Likun Ma
February 27, 2019 (v1)
Keywords: aluminum particle, diffusion flame, numerical simulation, steam, vortex combustor
In this paper we report a new development in the numerical model for aluminum-steam combustion. This model is based on the diffusion flame of the continuum regime and the thermal equilibrium between the particle and the flow field, which can be used to calculate the aluminum particle combustion model for two phase calculation conditions. The model prediction is in agreement with the experimental data. A new type of vortex combustor is proposed to increase the efficiency of the combustion of aluminum and steam, and the mathematical model of the two phase reacting flow in this combustor is established. The turbulence effects are modeled using the Reynolds Stress Model (RSM) with Linear Pressure-Strain approach, and the Eddy-Dissipation model is used to simulate the gas phase combustion. Aluminum particles are injected into the vortex combustor, forming a swirling flow around the chamber, whose trajectories are traced using the Discrete Phase Model (DPM). The simulation results show that... [more]
An Analysis Based on SD Model for Energy-Related CO₂ Mitigation in the Chinese Household Sector
Xingpeng Chen, Guokui Wang, Xiaojia Guo, Jinxiu Fu
February 27, 2019 (v1)
Keywords: CO2 emissions, household sector, system dynamics
Reducing carbon dioxide (CO₂) emissions has become a global consensus in response to global warming and climate change, especially to China, the largest CO₂ emitter in the world. Most studies have focused on CO₂ emissions from the production sector, however, the household sector plays an important role in the total energy-related CO₂ emissions. This study formulates an integrated model based on logarithmic mean Divisia index methodology and a system dynamics model to dynamically simulate household energy consumption and CO₂ emissions under different conditions. Results show the following: (1) the integrated model performs well in calculating the contribution of influencing factors on household CO₂ emissions and analyzing the options for CO₂ emission mitigation; (2) the increase in income is the dominant driving force of household CO₂ emissions, and as a result of the improved standard of living in China a sustained increase in household CO₂ emissions can be expected; (3) with decreasin... [more]
Validation of Generic Models for Variable Speed Operation Wind Turbines Following the Recent Guidelines Issued by IEC 61400-27
Andrés Honrubia-Escribano, Francisco Jiménez-Buendía, Emilio Gómez-Lázaro, Jens Fortmann
February 27, 2019 (v1)
Keywords: doubly-fed induction machine (DFIG), full-scale converter (FSC), generic model, IEC 61400-27, model validation, power system stability, standard model
Considerable efforts are currently being made by several international working groups focused on the development of generic, also known as simplified or standard, wind turbine models for power system stability studies. In this sense, the first edition of International Electrotechnical Commission (IEC) 61400-27-1, which defines generic dynamic simulation models for wind turbines, was published in February 2015. Nevertheless, the correlations of the IEC generic models with respect to specific wind turbine manufacturer models are required by the wind power industry to validate the accuracy and corresponding usability of these standard models. The present work conducts the validation of the two topologies of variable speed wind turbines that present not only the largest market share, but also the most technological advances. Specifically, the doubly-fed induction machine and the full-scale converter (FSC) topology are modeled based on the IEC 61400-27-1 guidelines. The models are simulated... [more]
Design and Output Performance Model of Turbodrill Blade Used in a Slim Borehole
Yu Wang, Bairu Xia, Zhiqiao Wang, Liguang Wang, Qin Zhou
February 27, 2019 (v1)
Keywords: granite section, multistage simulation models, output performances prediction, slim borehole, turbodrill
Small-diameter turbodrills have great potential for use in slim boreholes because of their lower cost and higher efficiency when used in geothermal energy and other underground resource applications. Multistage hydraulic components consisting of stators and rotors are key aspects of turbodrills. This study aimed to develop a suitable blade that can be used under high temperature in granite formations. First, prediction models for single- and multi-stage blades were established based on Bernoulli’s Equation. The design requirement of the blade for high-temperature geothermal drilling in granite was proposed. A Φ89 blade was developed based on the dimensionless parameter method and Bezier curve; the parameters of the blade, including its radial size, symotric parameters, and blade profiles, were input into ANASYS and CFX to establish a calculation model of the single-stage blade. The optimization of the blade structure of the small-diameter turbodrill enabled a multistage turbodrill mode... [more]
Assessment of the Usability and Accuracy of the Simplified One-Diode Models for Photovoltaic Modules
Vincenzo Franzitta, Aldo Orioli, Alessandra Di Gangi
February 27, 2019 (v1)
Keywords: four-parameter model, I-V characteristics, one-diode equivalent circuit, photovoltaic modules, solar energy, three-parameter model
Models for photovoltaic (PV) cells and panels, based on the diode equivalent circuit, have been widely used because they are effective tools for system design. Many authors have presented simplified one-diode models whose three or four parameters are calculated using the data extracted from the datasheets issued by PV panel manufactures and adopting some simplifying hypotheses and numerical solving techniques. Sometimes it may be difficult to make a choice among so many models. To help researchers and designers working in the area of photovoltaic systems in selecting the model that is fit for purpose, a criterion for rating both the usability and accuracy of simplified one-diode models is proposed in this paper. The paper minutely describes the adopted hypotheses, analytical procedures and operative steps to calculate the parameters of the most famous simplified one-diode equivalent circuits. To test the achievable accuracy of the models, a comparison between the characteristics of som... [more]
Hydraulic Hybrid Excavator—Mathematical Model Validation and Energy Analysis
Paolo Casoli, Luca Riccò, Federico Campanini, Andrea Bedotti
February 27, 2019 (v1)
Keywords: energy analysis, fuel saving, hydraulic hybrid excavator, numerical modeling
Recent demands to reduce pollutant emissions and improve energy efficiency have driven the implementation of hybrid solutions in mobile machinery. This paper presents the results of a numerical and experimental analysis conducted on a hydraulic hybrid excavator (HHE). The machinery under study is a middle size excavator, whose standard version was modified with the introduction of an energy recovery system (ERS). The proposed ERS layout was designed to recover the potential energy of the boom, using a hydraulic accumulator as a storage device. The recovered energy is utilized through the pilot pump of the machinery which operates as a motor, thus reducing the torque required from the internal combustion engine (ICE). The analysis reported in this paper validates the HHE model by comparing numerical and experimental data in terms of hydraulic and mechanical variables and fuel consumption. The mathematical model shows its capability to reproduce the realistic operating conditions of the... [more]
Two Dimensional Thermal-Hydraulic Analysis for a Packed Bed Regenerator Used in a Reheating Furnace
Chien-Nan Lin, Jiin-Yuh Jang, Yi-Shiun Lai
February 27, 2019 (v1)
Keywords: heat exchanger, packed bed, regenerator, reheating furnace
Packed bed is widely used for different industries and technologies, such as heat exchangers, heat recovery, thermal energy storage and chemical reactors. In modern steel industry, packed bed regenerator is widely utilized in the reheating furnace to increase the furnace efficiency. This study established a two dimensional numerical model to simulate a packed bed used in regenerative furnaces. The physical properties of fluids and packed stuffing (such as density, thermal conductivity, and specific heat) are considered as functions of temperature to adapt the large temperature variation in operation. The transient temperature profiles of the flue gas, packed bed, and air during the heating and regeneration period are examined for various switching time (30, 60, 120, and 240 s). The results reveal that, during the heating period, the spanwise averaged heat transfer coefficient is decreased along the longitudinal downstream direction, while during the regeneration period, the opposite tr... [more]
Horizontal Air-Ground Heat Exchanger Performance and Humidity Simulation by Computational Fluid Dynamic Analysis
Paolo Maria Congedo, Caterina Lorusso, Maria Grazia De Giorgi, Riccardo Marti, Delia D’Agostino
February 5, 2019 (v1)
Keywords: computational fluid dynamic (CFD), cooling, efficiency, ground heat exchanger, ground source heat pump, heating, humidity, ventilation, zero energy building (ZEB)
Improving energy efficiency in buildings and promoting renewables are key objectives of European energy policies. Several technological measures are being developed to enhance the energy performance of buildings. Among these, geothermal systems present a huge potential to reduce energy consumption for mechanical ventilation and cooling, but their behavior depending on varying parameters, boundary and climatic conditions is not fully established. In this paper a horizontal air-ground heat exchanger (HAGHE) system is studied by the development of a computational fluid dynamics (CFD) model. Summer and winter conditions representative of the Mediterranean climate are analyzed to evaluate operation and thermal performance differences. A particular focus is given to humidity variations as this parameter has a major impact on indoor air quality and comfort. Results show the benefits that HAGHE systems can provide in reducing energy consumption in all seasons, in summer when free-cooling can b... [more]
Modeling and Experimental Validation of a Low-Cost Radiation Sensor Based on the Photovoltaic Effect for Building Applications
Ángel Gómez-Moreno, Pedro José Casanova-Peláez, José Manuel Palomar-Carnicero, Fernando Cruz-Peragón
February 5, 2019 (v1)
Keywords: building, irradiance estimation, photovoltaic, solar cells, solar radiation, thermal drift
The energy consumed to cool buildings is very elevated and solar gains represent a high percentage of these cooling loads. To minimize the thermal load it is necessary to control external shading systems. This control requires continuous measurement of solar radiation in different locations of the building. However, for such applications the use of conventional irradiance sensors increases the cost and reduces the profitability of the installation. This paper is focused on the development, modeling, and experimental validation of low cost irradiation sensors based on photovoltaic effect in order to reduce the costs of dynamic external shading devices and to improve the profitability of the system. With this proposal, firstly, small commercial photovoltaic cells have been adapted for use as an irradiation measurement device. Subsequently, quasi-stationary and continuous experimental measurements of these silicon cells, facing south and installed horizontally, have been carried out in Ja... [more]
Simulation of Polygeneration Systems
Francesco Calise, Massimo Dentice D’Accadia
February 5, 2019 (v1)
Keywords: distributed generation, dynamic simulations, Polygeneration, Renewable and Sustainable Energy
This Special Issue aims at collecting the recent studies dealing with polygeneration systems, with a special focus on the possible integration of different technologies into a single system, able to convert one or multiple energy sources into energy services (electricity, heat and cooling) and other useful products (e.g., desalinized water, hydrogen, glycerin, ammonia, etc.). Renewable sources (solar, wind, hydro, biomass and geothermal), as well as fossil fuels, feeding advanced energy systems such as fuel cells and cogeneration systems, are considered. Special attention is paid to control strategies and to the management of the systems in general. Studies including thermoeconomic analyses and system optimizations are presented.
Numerical Investigation of Wind Conditions for Roof-Mounted Wind Turbines: Effects of Wind Direction and Horizontal Aspect Ratio of a High-Rise Cuboid Building
Takaaki Kono, Tetsuya Kogaki, Takahiro Kiwata
January 31, 2019 (v1)
Keywords: horizontal aspect ratio, large-eddy simulation (LES), roof-top, small wind turbine (SWT), wind condition, wind direction
From the viewpoint of installing small wind turbines (SWTs) on rooftops, this study investigated the effects of wind direction and horizontal aspect ratio (HAR = width/length) of a high-rise cuboid building on wind conditions above the roof by conducting large eddy simulations (LESs). The LES results confirmed that as HAR decreases (i.e., as the building width decreases), the variation in wind velocity over the roof tends to decrease. This tendency is more prominent as the angle between the wind direction and the normal vector of the building’s leeward face with longer roof edge increases. Moreover, at windward corners of the roof, wind conditions are generally favorable at relatively low heights. In contrast, at the midpoint of the roof's windward edge, wind conditions are generally not favorable at relatively low heights. At leeward representative locations of the roof, the bottoms of the height range of favorable wind conditions are typically higher than those at the windward repres... [more]
Dimensionless Maps for the Validity of Analytical Ground Heat Transfer Models for GSHP Applications
Paolo Conti
January 31, 2019 (v1)
Keywords: analytical models, dimensionless analysis, finite cylindrical heat source, finite linear heat source, ground heat transfer, ground-source heat pump systems, infinite cylindrical heat source, infinite linear heat source, purely-conductive media
This article provides plain and handy expressions to decide the most suitable analytical model for the thermal analysis of the ground source in vertical ground-coupled heat pump applications. We perform a comprehensive dimensionless analysis of the reciprocal deviation among the classical infinite, finite, linear and cylindrical heat source models in purely conductive media. Besides, we complete the framework of possible boreholes model with the “hollow” finite cylindrical heat source solution, still lacking in the literature. Analytical expressions are effective tools for both design and performance assessment: they are able to provide practical and general indications on the thermal behavior of the ground with an advantageous tradeoff between calculation efforts and solution accuracy. This notwithstanding, their applicability to any specific case is always subjected to the coherence of the model assumptions, also in terms of length and time scales, with the specific case of interest.... [more]
A Short-Term Outage Model of Wind Turbines with Doubly Fed Induction Generators Based on Supervisory Control and Data Acquisition Data
Peng Sun, Jian Li, Junsheng Chen, Xiao Lei
January 31, 2019 (v1)
Keywords: prediction model, short-term outage model, supervisory control and data acquisition (SCADA) data, wind turbine (WT)
This paper presents a short-term wind turbine (WT) outage model based on the data collected from a wind farm supervisory control and data acquisition (SCADA) system. Neural networks (NNs) are used to establish prediction models of the WT condition parameters that are dependent on environmental conditions such as ambient temperature and wind speed. The prediction error distributions are discussed and used to calculate probabilities of the operation of protection relays (POPRs) that were caused by the threshold exceedance of the environmentally sensitive parameters. The POPRs for other condition parameters are based on the setting time of the operation of protection relays. The union probability method is used to integrate the probabilities of operation of each protection relay to predict the WT short term outage probability. The proposed method has been used for real 1.5 MW WTs with doubly fed induction generators (DFIGs). The results show that the proposed method is more effective in W... [more]
Lumped Parameters Model of a Crescent Pump
Massimo Rundo, Alessandro Corvaglia
January 31, 2019 (v1)
Keywords: crescent pump, fluid power, internal gear pump, Modelling
This paper presents the lumped parameters model of an internal gear crescent pump with relief valve, able to estimate the steady-state flow-pressure characteristic and the pressure ripple. The approach is based on the identification of three variable control volumes regardless of the number of gear teeth. The model has been implemented in the commercial environment LMS Amesim with the development of customized components. Specific attention has been paid to the leakage passageways, some of them affected by the deformation of the cover plate under the action of the delivery pressure. The paper reports the finite element method analysis of the cover for the evaluation of the deflection and the validation through a contactless displacement transducer. Another aspect described in this study is represented by the computational fluid dynamics analysis of the relief valve, whose results have been used for tuning the lumped parameters model. Finally, the validation of the entire model of the p... [more]
Modeling of a Pouch Lithium Ion Battery Using a Distributed Parameter Equivalent Circuit for Internal Non-Uniformity Analysis
Dafen Chen, Jiuchun Jiang, Xue Li, Zhanguo Wang, Weige Zhang
January 31, 2019 (v1)
Keywords: distributed parameter equivalent circuit model, internal non-uniformity, lithium ion battery
A battery model that has the capability of analyzing the internal non-uniformity of local state variables, including the state of charge (SOC), temperature and current density, is proposed in this paper. The model is built using a set of distributed parameter equivalent circuits. In order to validate the accuracy of the model, a customized battery with embedded T-type thermocouple sensors inside the battery is tested. The simulated temperature conforms well with the measured temperature at each test point, and the maximum difference is less than 1 °C. Then, the model is applied to analyze the evolution processes of local state variables’ distribution inside the battery during the discharge process. The simulation results demonstrate drastic distribution changes of the local state variables inside the battery during the discharge process. The internal non-uniformity is originally caused by the resistance of positive and negative foils, while also influenced by the change rate of open ci... [more]
Analytical Model of a Dual Rotor Radial Flux Wind Generator Using Ferrite Magnets
Peifeng Xu, Kai Shi, Yuxin Sun, Huangqiu Zhu
January 31, 2019 (v1)
Keywords: analytical model, dual rotor radial flux wind generator, equivalent magnetic circuit, ferrite magnets, finite element method, Optimization
This paper presents a comprehensive analytical model for dual rotor radial flux wind generators based on the equivalent magnetic circuit method. This model is developed to predict the flux densities of the inner and outer air gaps, flux densities of the rotor and stator yokes, back electromotive force (EMF), electromagnetic torque, cogging torque, and some other characteristics important for generator design. The 2D finite element method (FEM) is employed to verify the presented analytical model, fine-tune it, and validate the prediction precision. The results show that the errors between the proposed analytical model and the FEM results are less than 5% and even less than 1% for certain parameters, that is, the results obtained from the proposed analytical model match well the ones obtained from FEM analysis. Meanwhile, the working points at different temperatures are confirmed to exceed the knee point of the BH curve, which means that irreversible demagnetization does not occur. Fina... [more]
Techno-Economic Modeling and Analysis of Redox Flow Battery Systems
Jens Noack, Lars Wietschel, Nataliya Roznyatovskaya, Karsten Pinkwart, Jens Tübke
January 30, 2019 (v1)
Keywords: cost, materials, redox flow battery, Technoeconomic Analysis
A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on an example of a 10 kW/120 kWh vanadium redox flow battery system, and the costs of the individual components were analyzed. Particular consideration was given to the influence of the material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model, it was possible to formulate statements about the targeted optimization of a developed non-commercial vanadium redox flow battery system and general aspects for future developments of redox flow batteries.
Offshore Power Plants Integrating a Wind Farm: Design Optimisation and Techno-Economic Assessment Based on Surrogate Modelling
Luca Riboldi, Lars O. Nord
January 17, 2019 (v1)
Keywords: combined cycle, hybrid system, kriging, multi-objective optimisation, offshore wind, oil and gas
The attempt to reduce the environmental impact of the petroleum sector has been the driver for researching energy efficient solutions to supply energy offshore. An attractive option is to develop innovative energy systems including renewable and conventional sources. The paper investigates the possibility to integrate a wind farm into an offshore combined cycle power plant. The design of such an energy system is a complex task as many, possibly conflicting, requirements have to be satisfied. The large variability of operating conditions due to the intermittent nature of wind and to the different stages of exploitation of an oil field makes it challenging to identify the optimal parameters of the combined cycle and the optimal size of the wind farm. To deal with the issue, an optimisation procedure was developed that was able to consider the performance of the system at a number of relevant off-design conditions in the definition of the optimal design. A surrogate modelling technique wa... [more]
Offshore Power Plants Integrating a Wind Farm: Design Optimisation and Techno-Economic Assessment Based on Surrogate Modelling
Luca Riboldi, Lars O. Nord
January 17, 2019 (v2)
Keywords: combined cycle, hybrid system, kriging, multi-objective optimisation, offshore wind, oil and gas
The paper investigates the possibility to integrate a wind farm into an offshore combined cycle power plant. The models used in the publication are here provided.
Hysteresis Characteristic in the Hump Region of a Pump-Turbine Model
Deyou Li, Hongjie Wang, Jinxia Chen, Torbjørn K. Nielsen, Daqing Qin, Xianzhu Wei
January 7, 2019 (v1)
Keywords: experimental investigation, hump characteristic, hysteresis characteristic, pump turbine
The hump feature is one of the major instabilities in pump-turbines. When pump-turbines operate in the hump region, strong noise and serious fluctuations can be observed, which are harmful to their safe and stable operation and can even destroy the whole unit as well as water conveyance system. In this paper, a low specific speed (nq = 36.1 min−1) pump-turbine model was experimentally investigated. Firstly, the hump characteristic was obtained under 19 mm guide vane opening conditions. More interestingly, when the hump characteristic was measured in two directions (increasing and decreasing the discharge), characteristic hysteresis was found in the hump region. The analysis of performance characteristics reveals that the hump instability is the result of Euler momentum and hydraulic losses, and different Euler momentum and hydraulic losses in the two development processes lead to the hysteresis phenomenon. Then, 12 pressure sensors were mounted in the different parts of the pump-turbin... [more]
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