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Dynamic Analysis of a 10 MW Floating Offshore Wind Turbine Considering the Tower and Platform Flexibility
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作者 GAO Shan ZHANG Lixian +3 位作者 SHI Wei WANG Wenhua WANG Bin LI Xin 《Journal of Ocean University of China》 CAS CSCD 2024年第2期358-370,共13页
Recently,semisubmersible floating offshore wind turbine technologies have received considerable attention.For the coupled simulation of semisubmersible floating offshore wind energy,the platform is usually considered ... Recently,semisubmersible floating offshore wind turbine technologies have received considerable attention.For the coupled simulation of semisubmersible floating offshore wind energy,the platform is usually considered a rigid model,which could affect the calculation accuracy of the dynamic responses.The dynamic responses of a TripleSpar floating offshore wind turbine equipped with a 10 MW offshore wind turbine are discussed herein.The simulation of a floating offshore wind turbine under regular waves,white noise waves,and combined wind-wave conditions is conducted.The effects of the tower and platform flexibility on the motion and force responses of the TripleSpar semisubmersible floating offshore wind turbine are investigated.The results show that the flexibility of the tower and platform can influence the dynamic responses of a TripleSpar semisubmersible floating offshore wind turbine.Considering the flexibility of the tower and platform,the tower and platform pitch motions markedly increased compared with the fully rigid model.Moreover,the force responses,particularly for tower base loads,are considerably influenced by the flexibility of the tower and platform.Thus,the flexibility of the tower and platform for the coupled simulation of floating offshore wind turbines must be appropriately examined. 展开更多
关键词 floating offshore wind turbine TripleSpar semisubmersible platform rigidity and flexibility platform coupled simulation
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CAS-ESM2.0 Successfully Reproduces Historical Atmospheric CO_(2) in a Coupled Carbon−Climate Simulation
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作者 Jiawen ZHU Juanxiong HE +6 位作者 Duoying JI Yangchun LI He ZHANG Minghua ZHANG Xiaodong ZENG Kece FEI Jiangbo JIN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期572-580,共9页
The atmospheric carbon dioxide(CO_(2))concentration has been increasing rapidly since the Industrial Revolution,which has led to unequivocal global warming and crucial environmental change.It is extremely important to... The atmospheric carbon dioxide(CO_(2))concentration has been increasing rapidly since the Industrial Revolution,which has led to unequivocal global warming and crucial environmental change.It is extremely important to investigate the interactions among atmospheric CO_(2),the physical climate system,and the carbon cycle of the underlying surface for a better understanding of the Earth system.Earth system models are widely used to investigate these interactions via coupled carbon-climate simulations.The Chinese Academy of Sciences Earth System Model version 2(CAS-ESM2.0)has successfully fixed a two-way coupling of atmospheric CO_(2)with the climate and carbon cycle on land and in the ocean.Using CAS-ESM2.0,we conducted a coupled carbon-climate simulation by following the CMIP6 proposal of a historical emissions-driven experiment.This paper examines the modeled CO_(2)by comparison with observed CO_(2)at the sites of Mauna Loa and Barrow,and the Greenhouse Gases Observing Satellite(GOSAT)CO_(2)product.The results showed that CAS-ESM2.0 agrees very well with observations in reproducing the increasing trend of annual CO_(2)during the period 1850-2014,and in capturing the seasonal cycle of CO_(2)at the two baseline sites,as well as over northern high latitudes.These agreements illustrate a good ability of CAS-ESM2.0 in simulating carbon-climate interactions,even though uncertainties remain in the processes involved.This paper reports an important stage of the development of CAS-ESM with the coupling of carbon and climate,which will provide significant scientific support for climate research and China’s goal of carbon neutrality. 展开更多
关键词 CAS-ESM atmospheric CO_(2) coupled carbon-climate simulation emissions-driven CMIP6 experiment
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Numerical Simulation and Experimental Study of Heat-fluid-solid Coupling of Double Flapper-nozzle Servo Valve 被引量:18
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作者 ZHAO Jianhua ZHOU Songlin +1 位作者 LU Xianghui GAO Dianrong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第5期1030-1038,共9页
The double flapper-nozzle servo valve is widely used to launch and guide the equipment. Due to the large instantaneous flow rate of servo valve working under specific operating conditions, the temperature of servo val... The double flapper-nozzle servo valve is widely used to launch and guide the equipment. Due to the large instantaneous flow rate of servo valve working under specific operating conditions, the temperature of servo valve would reach 120℃ and the valve core and valve sleeve deform in a short amount of time. So the control precision of servo valve significantly decreases and the clamping stagnation phenomenon of valve core appears. In order to solve the problem of degraded control accuracy and clamping stagnation of servo valve under large temperature difference circumstance, the numerical simulation of heat-fluid-solid coupling by using finite element method is done. The simulation result shows that zero position leakage of servo valve is basically impacted by oil temperature and change of fit clearance. The clamping stagnation is caused by warpage-deformation and fit clearance reduction of the valve core and valve sleeve. The distribution roles of the temperature and thermal-deformation of shell, valve core and valve sleeve and the pressure, velocity and temperature field of flow channel are also analyzed. Zero position leakage and electromagnet's current when valve core moves in full-stroke are tested using Electro-hydraulic Servo-valve Characteristic Test-bed of an aerospace sciences and technology corporation. The experimental results show that the change law of experimental current at different oil temperatures is roughly identical to simulation current. The current curve of the electromagnet is smooth when oil temperature is below 80℃, but the amplitude of current significantly increases and the hairy appears when oil temperature is above 80℃. The current becomes smooth again after the warped valve core and valve sleeve are reground. It indicates that clamping stagnation is caused by warpage-deformation and fit clearance reduction of valve core and valve sleeve. This paper simulates and tests the heat-fluid-solid coupling of double flapper-nozzle servo valve, and the obtained results provide the reference value for the design of double flapper-nozzle force feedback servo valve. 展开更多
关键词 double flapper-nozzle servo valve heat-fluid-solid coupling numerical simulation warpage-deformation clamping stagnation zero position leakage
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FE-based coupling simulation of Ti60 alloy in isothermal upsetting process 被引量:2
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作者 罗皎 李淼泉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第5期849-856,共8页
A constitutive equation was proposed to describe the effect of grain size on the deformation behavior.And a coupling simulation of deformation with heat transfer and microstructure was carried out in isothermal upsett... A constitutive equation was proposed to describe the effect of grain size on the deformation behavior.And a coupling simulation of deformation with heat transfer and microstructure was carried out in isothermal upsetting process of Ti60 alloy.The effects of processing parameters on the equivalent strain,the equivalent stress,the temperature rise and the grain size distribution in isothermal upsetting process of Ti60 alloy were analyzed.It is concluded that the uniformity of equivalent strain and equivalent stress increases with the increase of deformation temperature.However,the temperature rise and the grain size decreases with the increase of deformation temperature.The non-uniformity of equivalent strain,equivalent stress,temperature field and grain size increases with the increase of height reduction.And the calculated grain size using simulation is in good agreement with the experimental one. 展开更多
关键词 titanium alloy coupling simulation constitutive equation grain size
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Design of new resonant magnetic perturbation coils on the J-TEXT tokamak
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作者 黄卓 周松 +11 位作者 樊金荣 李达 饶波 王能超 丁永华 毛飞越 黄名响 田微 陈忠勇 陈志鹏 梁云峰 the J-TEXT Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第11期142-149,共8页
The resonant magnetic perturbation(RMP)system is a powerful auxiliary system on tokamaks.On the J-TEXT tokamak,a set of new in-vessel coils is designed to enhance the amplitude of the RMP.The new coils are designed to... The resonant magnetic perturbation(RMP)system is a powerful auxiliary system on tokamaks.On the J-TEXT tokamak,a set of new in-vessel coils is designed to enhance the amplitude of the RMP.The new coils are designed to be two-turn saddle coils.These two-turn saddle coils have been optimized in terms of their structure,support,and protection components to overcome the limitations of the narrow in-vessel space,resulting in a compact coil module that can be accommodated in the vessel.To verify the feasibility of this design,an electromagnetic simulation is performed to investigate the electrical parameters and the generated field of the coils.A multi-field coupled simulation is performed to investigate the capacity of heat dissipation.As a result of these efforts,the new RMP coils have been successfully installed on the J-TEXT tokamak.It has significantly enhanced the RMP amplitude and been widely applied in experiments. 展开更多
关键词 fusion engineering TOKAMAK resonant magnetic perturbation coil multi-field coupled simulation(Some fioures may appeari in colour only in the online iournal)
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Performance of elastic ball screen-cleaning device based on DEM-MBD coupling simulation
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作者 Yubin Bi Qingbin Song +6 位作者 Jingyu Zhu Jintao Feng Jianxin Dong Pengfei Zhao Yuxiang Huang Zuoli Fu Jixing Zhou 《Particuology》 SCIE EI CAS CSCD 2024年第10期247-263,共17页
In seed breeding, the vibrating screen used for pre-sowing grading parental seeds often has the problem of poor self-purification rate. Using elastic balls to clean the plugging seeds and ensure the self-purification ... In seed breeding, the vibrating screen used for pre-sowing grading parental seeds often has the problem of poor self-purification rate. Using elastic balls to clean the plugging seeds and ensure the self-purification of the screen is a viable technical solution. To clarify and improve the operating performance of the elastic ball particles, a DEM-MBD coupling simulation model of the elastic ball screen-cleaning device was established in this study, and a numerical simulation analysis of the complex motion process was carried out. The mechanism of action of the elastic ball was explained more completely from the aspects of excitation force and energy transfer. Through the Plackett-Burman test, it was determined that the vibration frequency has the most significant effect on the excitation force. Multiple linear regression analysis was performed on each factor and the mathematical relationship equation. It was found that when the maximum excitation force was greater than 7 N and the average excitation force was greater than 2 N, the self-purification rate was greater than 95%. The self-purification rate was then increased to 99.81% by variable frequency tests. The variable frequency achieved better self-purification effect. 展开更多
关键词 Seed breeding GRADING Vibrating screen SELF-PURIFICATION coupling simulation Variable frequency
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A computational platform for considering the effects of aerodynamic and seismic load combination for utility scale horizontal axis wind turbines 被引量:12
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作者 Mohammad-Amin Asareh Ian Prowell +1 位作者 Jeffery Volz William Schonberg 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2016年第1期91-102,共12页
The wide deployment of wind turbines in locations with high seismic hazard has led engineers to take into account a more comprehensive seismic design of such structures. Turbine specific guidelines usually use simplif... The wide deployment of wind turbines in locations with high seismic hazard has led engineers to take into account a more comprehensive seismic design of such structures. Turbine specific guidelines usually use simplified methods and consider many assumptions to combine seismic demand with the other operational loads effecting the design of these structures. As the turbines increase in size and capacity, the interaction between seismic loads and aerodynamic loads becomes even more important. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module is developed for the FAST code and described in this research. This platform allows engineers working in this industry to directly consider interaction between seismic and other environmental loads for turbines. This paper details the practical application and theory of this platform and provides examples for the use of different capabilities. The platform is then used to show the suitable earthquake and operational load combination with the implicit consideration of aerodynamic damping by estimating appropriate load factors. 展开更多
关键词 renewable energy horizontal axis wind turbines aerodynamic-seismic load interaction aerodynamicdamping coupled simulations
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COUPLED SIMULATION OF 3D ELECTRO-MAGNETO-FLOW FIELD IN HALL-HEROULT CELLS USING FINITE ELEMENT METHOD 被引量:10
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作者 J. Li W. Liu +2 位作者 Y.Q. Lai Q.Y. Li Y.X. Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2006年第2期105-116,共12页
Two full 3D steady mathematical models are developed by finite element method (FEM) to calcalate coupled physics fields. the electro-magnetic model is built and solved first and so is the fluid motion model with the... Two full 3D steady mathematical models are developed by finite element method (FEM) to calcalate coupled physics fields. the electro-magnetic model is built and solved first and so is the fluid motion model with the acquired electromagnetic force as source body forces in Navier-Stokes equations. Effects caused by the ferromagnetic shell, busbar system around, and open boundary problem as well as inside induced current were considered in terms of the magnetic field. Furthermore, a new modeling method is found to set up solid models and then mesh them entirely with so-called structuralized grids, namely hex-mesh. Examples of 75kA prebaked cell with two kinds of busbar arrangements are presented. Results agree with those disclosed in the literature and confirm that the coupled simulation is valid. It is also concluded that the usage of these models facilitates the consistent analysis of the electric field to magnetic field and then flow motion to the greater extent, local distributions of current density and magnetic flux density are very much dependent on the cell structure, the steel shell is a shield to reduce the magnetic field and flow pattern is two dimensional in the main body of the metal pad. 展开更多
关键词 coupled simulation electromagnetic field flow field aluminum reduction cell finite element analysis
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Cast-rolling force model in solid-liquid cast-rolling bonding(SLCRB) process for fabricating bimetal clad strips 被引量:7
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作者 Jun-peng ZHANG Hua-gui HUANG +2 位作者 Ri-dong ZHAO Miao FENG Kai MENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第3期626-635,共10页
Based on twin-roll casting, a cast-rolling force model was proposed to predict the rolling force in the bimetal solid-liquid cast-rolling bonding(SLCRB) process. The solid-liquid bonding zone was assumed to be below t... Based on twin-roll casting, a cast-rolling force model was proposed to predict the rolling force in the bimetal solid-liquid cast-rolling bonding(SLCRB) process. The solid-liquid bonding zone was assumed to be below the kiss point(KP). The deformation resistance of the liquid zone was ignored. Then, the calculation model was derived. A 2D thermal-flow coupled simulation was established to provide a basis for the parameters in the model, and then the rolling forces of the Cu/Al clad strip at different rolling speeds were calculated. Meanwhile, through measurement experiments, the accuracy of the model was verified. The influence of the rolling speed, the substrate strip thickness, and the material on the rolling force was obtained. The results indicate that the rolling force decreases with the increase of the rolling speed and increases with the increase of the thickness and thermal conductivity of the substrate strip. The rolling force is closely related to the KP height. Therefore, the formulation of reasonable process parameters to control the KP height is of great significance to the stability of cast-rolling forming. 展开更多
关键词 bimetal clad strip solid−liquid cast-rolling bonding rolling force calculation model kiss point thermal−flow coupled simulation
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Wave-tide-surge coupled model simulation for Typhoon Maemi 被引量:4
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作者 CHOI Byung Ho KIM Dong Chule +1 位作者 KIM Young Bok KIM Hyun Seung 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2007年第1期35-47,共13页
Reasonably accurate predictions of wave heights, current and elevations during storm events are vital information for marine operations and design of offshore and coastal structures in the surrounding seas of Korea Pe... Reasonably accurate predictions of wave heights, current and elevations during storm events are vital information for marine operations and design of offshore and coastal structures in the surrounding seas of Korea Peninsula. Ocean circulation and wind-wave models have traditionally been run separately, but recent researches have identified potentially important interactions between current and wave motions. The coupled tide-surge and the WAM wave models at the atmospheric boundary layer and bottom boundary layer around the Korea Peninsula are applied for the Typhoon Maemi (0314) event. Communication between the models is aehievod using MPI. Results are compared with coastal tide gauges and moored wave buoys and comparisons are also made between wave computations from the coupled model and the independent third generation wave models. Results suggest that applying the fide-surge-coupled model can be an effective means of obtaining wave and storm surge predictions simultaneously. 展开更多
关键词 wave-tide-surge coupled simulation Typhoon Maemi wave models
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Time-Domain Simulation for Coupled Motions of Three Barges Moored Side-by-Side in Floatover Operation 被引量:12
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作者 许鑫 杨建民 +1 位作者 李欣 徐亮瑜 《China Ocean Engineering》 SCIE EI CSCD 2015年第2期155-168,共14页
Simulating the coupled motions of multiple bodies in the time domain is a complex problem because of the strong hydrodynamic interactions and coupled effect of various mechanical connectors. In this study, we investig... Simulating the coupled motions of multiple bodies in the time domain is a complex problem because of the strong hydrodynamic interactions and coupled effect of various mechanical connectors. In this study, we investigate the hydrodynamic responses of three barges moored side-by-side in a floatover operation in the frequency and time domains. In the frequency domain, the damping lid method is adopted to improve the overestimated hydrodynamic coefficients calculated from conventional potential flow theory. A time-domain computing program based on potential flow theory and impulse theory is compiled for analyses that consider multibody hydrodynamic interactions and mechanical effects from lines and fenders. Correspondingly, an experiment is carried out for comparison with the numerical results. All statistics, time series, and power density spectra from decay and irregular wave tests are in a fairly good agreement. 展开更多
关键词 coupled motion time-domain simulation side-by-side floatover
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Coupled simulation of recirculation zonal firebox model and detailed kinetic reactor model in an industrial ethylene cracking furnace 被引量:8
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作者 Zhou Fang Tong Qiu Weiguo Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第8期1091-1100,共10页
A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convecti... A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convection to simulate heat transfer in the furnace.A two-dimensional recirculation model is proposed to estimate the flow field in furnace.The reactor model integrates the feedstock reconstruction model,an auto-generator of detail kinetic schemes,and the reactor simulation model to simulate the reaction process in the tubular coil.The coupled simulation result is compared with industrial process and shows agreement within short computation time. 展开更多
关键词 Ethylene cracking Coupled simulation Tubular furnace Recirculation zone modeling Detailed reaction kinetic
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Microstructure and mechanical properties of friction stir processed TA5 alloy 被引量:2
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作者 Li ZHOU Ming-run YU +5 位作者 Wei-guang CHEN Zi-li ZHANG Shuai DU Hui-jie LIU Yan YU Fu-yang GAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第2期404-415,共12页
Ultra-fine grained TA5 titanium alloy was fabricated by friction stir processing(FSP).Temperature distribution and material flow were simulated by the coupled Euler−Lagrange(CEL)method.The microstructure and mechanica... Ultra-fine grained TA5 titanium alloy was fabricated by friction stir processing(FSP).Temperature distribution and material flow were simulated by the coupled Euler−Lagrange(CEL)method.The microstructure and mechanical properties of TA5 alloy were characterized by optical and scanning electron microscope,Vickers hardness,and tensile tests.The processed alloy was composed of ultra-fine grained and equiaxed grains due to dynamic recrystallization.The microstructure recrystallized through grain boundary rotation and dislocation accumulation.The grain size reached the minimum on the advancing side of the stir zone with the highest grain misorientation.Ultimate tensile strength was promoted to over 830 MPa after FSP at a rotating speed of 200 r/min,whereas elongation varied a little.The specimens all fractured on the retreating side of the stir zone and smaller dimples were depicted from the fracture morphologies of FSP specimens. 展开更多
关键词 friction stir processing TA5 alloy coupled Euler−Lagrange simulation TEXTURE mechanical properties
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3D numerical simulation of boreholes for gas drainage based on the pore–fracture dual media 被引量:5
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作者 Wei Jianping Li Bo +1 位作者 Wang Kai Sun Donghui 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第4期739-744,共6页
A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeab... A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeability dynamic evolution was established by analyzing the variation in effective stress during gas drainage and the action mechanism of the effect of coal matrix desorption on porosity and fracture in the coal body.A coupling model can then be obtained to characterize gas compressibility and coal deformability under the gas–solid coupling of loading coal.In addition,a 3D model of boreholes was established and solved for gas drainage based on the relevant physical parameters of real mines.The comparison and analysis results for the law of gas migration and the evolution of coal body permeability around the boreholes before and after gas extraction between the dual media and the single-seepage field models can provide a theoretical basis for further research on the action mechanism of gas drainage. 展开更多
关键词 Pore-fracture Matrix exchange coupling model Numerical simulation Gas drainage
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MD simulation of a copper rod under thermal shock 被引量:4
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作者 Rong-Hou Xia Xiao-Geng Tian Ya-Peng Shen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第4期599-604,共6页
In this paper, thermoelastic problem of onedimensional copper rod under thermal shock is simulated using molecular dynamics method by adopting embedded atom method potential. The rod is on axis x, the left outermost s... In this paper, thermoelastic problem of onedimensional copper rod under thermal shock is simulated using molecular dynamics method by adopting embedded atom method potential. The rod is on axis x, the left outermost surface of which is traction free and the right outermost surface is fixed. Free boundary condition is imposed on the outermost surfaces in direction y and z. The left and right ends of the rod are subjected to hot and cold baths, respectively. Temperature, displacement and stress distributions are obtained along the rod at different moments, which are shown to be limited in the mobile region, indicating that the heat propagation speed is limited rather than infinite. This is consistent with the prediction given by generalized thermoelastic theory. From simulation results we find that the speed of heat conduction is the same as the speed of thermal stress wave. In the present paper, the simulations are conducted using the large-scale atomic/molecular massively parallel simulator and completed visualization software. 展开更多
关键词 Embedded atom method potential Molecular dynamics simulation Thermoelastic coupling Thermal stress
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Research on valve core’s clamping stagnation of double flapper-nozzle servo valve 被引量:1
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作者 Zhao Jianhua Zhang Bin +3 位作者 Chen Tao Wang Qiang Zhou Songlin Gao Dianrong 《High Technology Letters》 EI CAS 2019年第1期65-73,共9页
Due to great changing of instantaneous temperature of hydraulic oil of double flapper-nozzle servo valve, thermal deformation between valve core and valve sleeve may result in catching phenomenon of valve core, and th... Due to great changing of instantaneous temperature of hydraulic oil of double flapper-nozzle servo valve, thermal deformation between valve core and valve sleeve may result in catching phenomenon of valve core, and then the reliability of servo valve could be affected seriously. The work focuses on a particular model of double flapper-nozzle servo valve and establishes three dimension couple models of liquid-solid-thermal under extreme operating condition. The transmission route and dissipative mechanism of heat is revealed and thermal deformation behavior of valve core and valve sleeve is researched. A change law of the key fit clearance under the effect of thermal expansion and warp deformation is explored, the source of catching phenomenon of valve core is identified, and then preventive measure and improvement can be proposed. In order to verify the correctness of theoretical analysis, the moving smoothness of deformed valve core and reground valve core under the circumstance of high-temperature hydraulic oil on electrohydraulic servo valve static characteristics test table is compared and tested. The results show that as oil temperature rises, relative deformations between valve core and valve sleeve in different direction at a same cross-section are not equal, and then the key fit clearance is less than the initial value. Relative deformations in the same direction at different axial position are not equal, the deformations of middle and two ends are maximum and minimum values respectively, and then warp deformation of valve core occurs. When oil temperature is higher, the relative deformations between valve core and valve sleeve is larger, the moving smoothness of valve core gets worse, and the catching phenomenon of valve core occurs. Axial deformation of valve sleeve and valve core at different axial position is different, and the opening coefficient and stability of servo valve could be affected, especially the operation circumstance of small opening. The study can provide some guidance for designing double nozzle flapper servo valves. 展开更多
关键词 double flapper-nozzle servo valve flow-solid-thermal coupling numerical simulation catching phenomenon thermal deformation mechanism smooth movement
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Influence of oxidant KMnO_4 on film-forming process of rare earth metal conversion coating on LY12 aluminum alloy 被引量:1
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作者 TianzhuGao JiuqingLi 《Journal of University of Science and Technology Beijing》 CSCD 2002年第3期216-220,共5页
A Cu/Al galvanic couple was established to study the influence of the oxidantKMnO_4 on the film-forming process of rare earth metal (REM) conversion coating on LY12 aluminumalloy. It is found that the galvanic couple ... A Cu/Al galvanic couple was established to study the influence of the oxidantKMnO_4 on the film-forming process of rare earth metal (REM) conversion coating on LY12 aluminumalloy. It is found that the galvanic couple simulative experiment accords with the actual immersion,and it can be substantially used to simulate the behavior of LY12 aluminum alloy in thefilm-forming process. It is showed that the formation of the coating is quickened in CeCl_3 solutioncontaining KMnO_4 compared with that not containing KMnO_4. XPS results reveal that the coatingformed on cathode is composed of oxide or hydroxide of Ce and Mn, so the mechanism of formation ofREM conversion coating changes when KMnO4 is added. 展开更多
关键词 copper containing aluminum alloy rare earth metal conversion coating galvanic couple simulative experiment
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Controlling Roll Temperature by Fluid-Solid Coupled Heat Transfer 被引量:2
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作者 Jing-Feng Zou Li-Feng Ma +3 位作者 Guo-Hua Zhang Zhi-Quan Huang Jin-Bao Lin Peng-Tao Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第5期66-79,共14页
Currently, when magnesium alloy sheet is rolled, the method of controlling roll temperature is simple and inaccurate. Furthermore, roll temperature has a large influence on the quality of magnesium alloy sheet; theref... Currently, when magnesium alloy sheet is rolled, the method of controlling roll temperature is simple and inaccurate. Furthermore, roll temperature has a large influence on the quality of magnesium alloy sheet; therefore, a new model using circular fluid flow control roll temperature has been designed. A fluid heat transfer structure was designed, the heat transfer process model of the fluid heating roll was simplified, and the finite di erence method was used to cal?culate the heat transfer process. Fluent software was used to simulate the fluid?solid coupling heat transfer, and both the trend and regularity of the temperature field in the heat transfer process were identified. The results show that the heating e ciency was much higher than traditional heating methods(when the fluid heat of the roll and tempera?ture distribution of the roll surface was more uniform). Moreover, there was a bigger temperature di erence between the input and the output, and after using reverse flow the temperature di erence decreased. The axial and circum?ferential temperature distributions along the sheet were uniform. Both theoretical calculation results and numerical simulation results of the heat transfer between fluid and roll were compared. The error was 1.8%–12.3%, showing that the theoretical model can both forecast and regulate the temperature of the roll(for magnesium alloy sheets) in the rolling process. 展开更多
关键词 Magnesium alloy Fluid heating Heat transfer model Numerical simulation of fluid?solid coupling
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Coupled Eulerian-Lagrangian simulation of a modified direct shearapparatus for the measurement of residual shear strengths 被引量:1
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作者 Luke Tatnell Ashley P.Dyson Ali Tolooiyan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第5期1113-1123,共11页
The simulation of large-strain geotechnical laboratory tests with conventional Lagrangian finite element method(FEM)techniques is often problematic due to excessive mesh distortion.The multiple reversal direct shear(M... The simulation of large-strain geotechnical laboratory tests with conventional Lagrangian finite element method(FEM)techniques is often problematic due to excessive mesh distortion.The multiple reversal direct shear(MRDS)test can be used to measure the residual shear strength of soils in a laboratory setting.However,modelling and simulation generally require advanced numerical methods to accommodate the large shear strains concentrated in the shear plane.In reality,when the standard direct shear(DS)apparatus is used,the MRDS method is prone to two major sources of measurement error:load cap tilting and specimen loss.These sources of error make it difficult or even impossible to correctly determine the residual shear strength.This paper presents a modified DS apparatus and multi-reversal multi-stage test method,simulated using the coupled Eulerian-Lagrangian(CEL)method in a finite element environment.The method was successful in evaluating equipment and preventing both load cap tilting and specimen loss,while modelling large-deformation behaviour that is not readily simulated with the conventional FEM or arbitrary Lagrangian-Eulerian(ALE)analysis.Thereafter,a modified DS apparatus was created for the purpose of analysing mixtures of organic materials found in an Australian clay.The results obtained from the modified DS CEL model in combination with laboratory tests show a great improvement in the measured residual shear strength profiles compared to those from the standard apparatus.The modified DS setup ensures that accurate material residual shear strengths are calculated,a factor that is vital to ensure appropriate soil behaviour is simulated for numerical analyses of large-scale geotechnical projects. 展开更多
关键词 Coupled Eulerian-Lagrangian(CEL)simulation Residual shear strength MULTI-STAGE Direct shear(DS) Organic content Cohesive soil
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An Integrated Structural Strength Analysis Method for Spar Type Floating Wind Turbine
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作者 胡志强 刘毅 王晋 《China Ocean Engineering》 SCIE EI CSCD 2016年第2期217-230,共14页
An integrated structural strength analysis method for a Spar type floating wind turbine is proposed in this paper,and technical issues related to turbine structure modeling and stress combination are also addressed.Th... An integrated structural strength analysis method for a Spar type floating wind turbine is proposed in this paper,and technical issues related to turbine structure modeling and stress combination are also addressed.The NREL-5MW "Hywind" Spar type wind turbine is adopted as study object.Time-domain dynamic coupled simulations are performed by a fully-coupled aero-hydro-servo-elastic tool,FAST,on the purpose of obtaining the dynamic characteristics of the floating wind turbine,and determining parameters for design load cases of finite element calculation.Then design load cases are identified,and finite element analyses are performed for these design load cases.The structural stresses due to wave-induced loads and wind-induced loads are calculated,and then combined to assess the structural strength of the floating wind turbine.The feasibility of the proposed structural strength analysis method for floating wind turbines is then validated. 展开更多
关键词 floating wind turbine structural strength analysis method dynamic coupled simulation finite element analysis
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