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| 1 | Chebyshev Fitting Way and Error Analysis for Propeller Atlas across Four Quadrants显示文摘A Chebyshev fitting way for a propeller atlas across four quadrants is discussed. As an example, Chebyshev polynomialfitting results and its error analysis are given. Because it’s difficult generally to get a propeller atlas across four quadrants,a wayis used to construct an alternative with higher accuracy based on the properties. As an application example, an alternative forthe propeller property of a Deep Submergence Vebicle across four quadrants is given practically and a simulation model of | LI Dian-pu, WANG Zong-yi, CHI Hai-hong College of Automation , Harbin Engineering University, Harbin 150001, China | 2002 | Journal of Marine Science and Application2002，1，1： | 20 |
| 2 | Theory on real-time control of construction quality and progress and its application to high arc dam显示文摘A complete scheme for solving the key scientific problems associated with high-standard,high-intensity continuous construction of high arch dams was presented. First,based on a coupling analysis of construction system decomposition and coordination for a high arc dam,a mathematical model for real-time control of construction quality and progress that considers complex constraints was developed. Second,a method of progress control was proposed based on a dynamic simulation. Third,a dynamic quality control mechanism was established based on construction information collected using a PDA. Fourth,a system for integrating collected information,progress simulation and quality control analyses under a network environment was developed. Finally,these methods were applied to a practical project to show that each aspect of a construction process can be managed effectively and that real-time monitoring and feedback control can be realized. Our methods provide new theoretical principles and technical measures for quality and progress control in the high arc dam construction process. | ZHONG DengHua1, REN BingYu1, LI MingChao1, WU BinPing1 & LI MingChuan2 1 Department of Hydraulic and Hydroelectric Engineering, School of Civil Engineering, Tianjin University, Tianjin 300072, China 2 Ertan Hydropower Development Company, Ltd., Chengdu 610051, China | 2010 | Science China(Technological Sciences)2010，53，10： | 18 |
| 3 | Analysis and discussion on launching mechanism and tactical electromagnetic railgun technology显示文摘This paper begins with a discussion on the significance of multi-physical fields in the research of railgun launching mechanism, followed by an introduction of research work about dynamic measurements and numerical simulations. The application of some measurement methods including the atomic emission spectrum, fiber-optic strain, optical level, pulsed X-ray, and high-speed video in observing the launching process was introduced. The models about the electromechanical dynamic processes and multi-physical fields in a railgun were developed. The mechanisms of the grooving, arc transition, and gouging were analyzed. These work provided a deeper understanding of launching mechanism of electromagnetic railgun. Some issues about the tactical railgun, such as the fiber composite overwrapped barrel, recoil,loading modes and eddy current loss were also discussed. Taking a medium-caliber launcher as an example, the basic process of design and analysis was introduced. | Bao-ming Li Qing-hua Lin | 2018 | Defence Technology(防务技术)2018，14，5： | 13 |
| 4 | Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer显示文摘MASNUM wave-tide-circulation coupled numerical model (MASNUM coupled model, hereinafter) is de-veloped based on the Princeton Ocean Model (POM). Both POM and MASNUM coupled model are ap-plied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. The upwelling mechanisms are analyzed from the viewpoint of tide, and a new mechanism is proposed. The study suggests that the tidally inducing mechanism of the upwelling in-cludes two dynamic aspects: the barotropic and the baroclinic process. On the one hand, the residual currents induced by barotropic tides converge near the seabed, and upwelling is generated to maintain mass conservation. The climbing of the residual currents along the sea bottom slope also contributes to the upwelling. On the other hand, tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances. Strong tidal mixing leads to conspicuous front in the coastal waters. The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front, and the upwelling branch appears near the frontal zone. Numerical experiments are de-signed to determine the importance of tide in inducing the upwelling. The results indicate that tide is a key and dominant inducement of the upwelling. Experiments also show that coupling calculation of the four main tidal constituents (M2, S2, K1, and O1), rather than dealing with the single M2 constituent, im-proves the modeling precision of the barotropic tide-induced upwelling. | L XinGang1,2,3,4, QIAO FangLi1,2, XIA ChangShui1,2 & YUAN YeLi1,2 1 The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China 2 Key Laboratory of Marine Science and Numerical Modeling (MASNUM), State Oceanic Administration, Qingdao 266061, China 3 Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China 4 Graduate University of the Chinese Academy of Sciences, Beijing 100039, China | 2007 | Science China Earth Sciences2007，50，3： | 9 |
| 5 | Prediction of Dynamic Cutting Force and Regenerative Chatter Stability in Inserted Cutters Milling显示文摘Currently, the modeling of cutting process mainly focuses on two aspects: one is the setup of the universal cutting force model that can be adapted to a broader cutting condition; the other is the setup of the exact cutting force model that can accurately reflect a true cutting process. However, there is little research on the prediction of chatter stablity in milling. Based on the generalized mathematical model of inserted cutters introduced by ENGIN, an improved geometrical, mechanical and dynamic model for the vast variety of inserted cutters widely used in engineering applications is presented, in which the average directional cutting force coefficients are obtained by means of a numerical approach, thus leading to an analytical determination of stability lobes diagram (SLD) on the axial depth of cut. A new kind of SLD on the radial depth of cut is also created to satisfy the special requirement of inserted cutter milling. The corresponding algorithms used for predicting cutting forces, vibrations, dimensional surface finish and stability lobes in inserted cutter milling under different cutting conditions are put forward. Thereafter, a dynamic simulation module of inserted cutter milling is implemented by using hybrid program of Matlab with Visual Basic. Verification tests are conducted on a vertical machine center for Aluminum alloy LC4 by using two different types of inserted cutters, and the effectiveness of the model and the algorithm is verified by the good agreement of simulation result with that of cutting tests under different cutting conditions. The proposed model can predict the cutting process accurately under a variety of cutting conditions, and a high efficient and chatter-free milling operation can be achieved by a cutting condition optimization in industry applications. | LI Zhongqun LIU Qiang YUAN Songmei HUANG Kaisheng | 2013 | Chinese Journal of Mechanical Engineering2013，26，3： | 8 |
| 6 | A METHOD IN SYSTEM DESIGN OF EJECTING DEVICES OF MISSILES显示文摘Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundation flr thw design of mew ejecting device is provided.The system design includes the distribution of techmology specifica-tion,3-D solid modeling of ejecting devices of missiles im-ported from abroad,the design of pmeumatic device sys-tem,the design of ejecting mechanism system,the predic-tion of reliability and the experimental analysis,etc. | DaiLongcheng XuanYimin | 2002 | Transactions of Nanjing University of Aeronautics and Astronautics2002，19，1： | 8 |
| 7 | Numerical simulation of seismic damage and cracking of concrete slabs of high concrete face rockfill dams显示文摘Based on the damage constitutive model for concrete, the Weibull distribution function was used to characterize the random distribution of the mechanical properties of materials by finely subdividing concrete slab elements, and a concrete random mesoscopic damage model was established. The seismic response of a 100-m high concrete face rockfill dam(CFRD), subjected to ground motion with different intensities, was simulated with the three-dimensional finite element method(FEM), with emphasis on exploration of damage and the cracking process of concrete slabs during earthquakes as well as analysis of dynamic damage and cracking characteristics during strong earthquakes. The calculated results show that the number of damaged and cracking elements on concrete slabs grows with the duration of earthquakes. With increasing earthquake intensity, the damaged zone and cracking zone on concrete slabs grow wider. During a 7.0-magnitude earthquake, the stress level of concrete slabs is low for the CFRD, and there is almost no damage or slight damage to the slabs. While during a 9.0-magnitude strong earthquake, the percentages of damaged elements and macrocracking elements continuously ascend with the duration of the earthquake, peaking at approximately 26% and 5% at the end of the earthquake, respectively. The concrete random mesoscopic damage model can depict the entire process of sprouting, growing, connecting, and expanding of cracks on a concrete slab during earthquakes. | Wei-jun Cen Lang-sheng Wen Zi-qi Zhang Kun Xiong | 2016 | Water Science and Engineering2016，9，3： | 7 |
| 8 | A New Method for Modelling and Simulation of the Dynamic Behaviour of the Wheel-rail contact显示文摘This paper presents a new method for modelling and simulation of the dynamic behaviour of the wheel-rail contact. The proposed dynamic wheel-rail contact model comprises wheel-rail contact geometry, normal contact problem, tangential contact problem and wheelset dynamic behaviour on the track. This two-degree of freedom model takes into account the lateral displacement of the wheelset and the yaw angle. Single wheel tread rail contact is considered for all simulations and Kalker s linear theory and heuristic non-linear creep models are employed. The second order differential equations are reduced to first order and the forward velocity of the wheelset is increased until the wheelset critical velocity is reached. This approach does not require solving mathematical equations in order to estimate the critical velocity of the dynamic wheel-rail contact model. The mathematical model is implemented in Matlab using numerical differentiation method. The simulated results compare well with the estimated results based on classical theory related to the dynamic behaviour of rail-wheel contact so the model is validated. | Arthur Anyakwo Crinela Pislaru Andrew Ball | 2012 | International Journal of Automation and computing2012，9，3： | 7 |
| 9 | Hydrate agglomeration modeling and pipeline hydrate slurry flow behavior simulation显示文摘Dynamic modeling and numerical simulation of hydrate slurry flow behavior are of great importance to offshore hydrate management.For this purpose, a dynamic model of hydrate agglomeration was proposed in this paper.Based on population balance equation, the frame of the dynamic model was established first, which took both hydrate agglomeration and hydrate breakage into consideration.Then, the calculating methods of four key parameters involved in the dynamic model were given according to hydrate agglomeration dynamics.The four key parameters are collision frequency, agglomeration efficiency, breakage frequency and the size distribution of sub particles resulting from particle breakage.After the whole dynamic model was built, it was combined with several traditional solid–liquid flow models and then together solved by the CFD software FLUENT 14.5.Finally, using this method, the influences of flow rate and hydrate volume fraction on hydrate particle size distribution, hydrate volume concentration distribution and pipeline pressure drop were simulated and analyzed. | Guangchun Song Yuxing Li Wuchang Wang Kai Jiang Zhengzhuo Shi Shupeng Yao | 2019 | Chinese Journal of Chemical Engineering2019，27，1： | 6 |
| 10 | Numerical investigation of aerodynamic flow actuation produced by surface plasma actuator on 2D oscillating airfoil显示文摘Numerical simulation of unsteady flow control over an oscillating NACA0012 airfoil is investigated. Flow actuation of a turbulent flow over the airfoil is provided by low current DC surface glow discharge plasma actuator which is analytically modeled as an ion pressure force produced in the cathode sheath region. The modeled plasma actuator has an induced pressure force of about 2 k Pa under a typical experiment condition and is placed on the airfoil surface at 0% chord length and/or at 10% chord length. The plasma actuator at deep-stall angles(from 5° to 25°) is able to slightly delay a dynamic stall and to weaken a pressure fluctuation in down-stroke motion. As a result, the wake region is reduced. The actuation effect varies with different plasma pulse frequencies, actuator locations and reduced frequencies. A lift coefficient can increase up to 70% by a selective operation of the plasma actuator with various plasma frequencies and locations as the angle of attack changes. Active flow control which is a key advantageous feature of the plasma actuator reveals that a dynamic stall phenomenon can be controlled by the surface plasma actuator with less power consumption if a careful control scheme of the plasma actuator is employed with the optimized plasma pulse frequency and actuator location corresponding to a dynamic change in reduced frequency. | Minh Khang Phan Jichul Shin | 2016 | Chinese Journal of Aeronautics2016，29，4： | 5 |
| 11 | Evaluation and scenario simulation for forest ecological security in China显示文摘Continuously growing populations and rapid economic development have led to the excessive use of forest resources,and the forest ecosystem is threatened.In response,forest ecological security(FES)has attracted attention.In this study,an integrated dynamic simulation model was constructed using the system dynamic method,and it was used to evaluate the FES in China from 1999 to 2014.A scenario analysis was then used to evaluate the changes in the FES under five forestry policy scenarios for the 2015–2050 period,including the baseline,afforestation policy,harvesting policies,management policy,investment policy,and a policy mix.The results showed that the evaluation values of the FES increased during the period from 1999 to 2002,the period from 2004 to 2010 and the year 2014,and they decreased in 2003 and during the period from 2011 to 2013.During the 2015–2050 simulation period,the FES improved continuously.In particular,China would enter a new stage when the economic systems,social systems and ecosystems were in harmony after 2040.To improve the FES and the current status of the FES,a scenario analysis showed the most suitable scenario to be Scenario 5 from 2015 to 2020 and Scenario 2 from 2021 to 2050.To relieve pressure,the most suitable scenario would be Scenario 5 from 2015 to 2040 and from 2046 to 2050,and the most suitable scenario would be Scenario 4 for 2041–2045.A policy mix(Scenario 5)would be most efficient under current conditions,while the effects of all the benefits of the forestry policies would weaken over the long term.The integrated method can be regarded as a decision support tool to help policy makers understand FES and promulgate a reasonable forestry policy. | Qin Zhang Guangyu Wang Feng Mi Xuanchang Zhang Lianzhen Xu Yufang Zhang Xiaoli Jiang | 2019 | Journal of Forestry Research2019，30，5： | 5 |
| 12 | Dynamic instability of a pump-turbine in load rejection transient process显示文摘Load rejection is one of the most crucial transient processes in pump-turbines. However, only a few achievements on the internal flow mechanism of pump-turbines in load rejection processes have been presented. In this study, firstly, the load rejection process in a pump-turbine was simulated with a three-dimensional unsteady turbulent numerical method using the technology of dynamic mesh and the user-defined functions in the FLUENT software. The rotational speed predicted through numerical simulation agrees well with experimental data. Secondly, based on numerical simulations, a dynamic instability in the load rejection process was found and presented that the pressure and performance characteristics, including hydraulic torque on the runner and the discharge, fluctuate in the overall trend. Meanwhile, all the performance characteristics and the pressure fluctuate sharply near the operating condition points, where hydraulic torque on the runner is equal to zero or reverse flow is maximum at reverse pump conditions. Finally, the time-frequency features and formation mechanism of the dynamic instability were analyzed emphatically. The analysis of the internal flow in the pump-turbine reveals that dynamic instability in the load rejection process are mainly caused by the vortex flow in the tandem cascades regions. Furthermore, the possible methods to improve the dynamic instability in the load rejection process were recommended. | FU XiaoLong LI DeYou WANG HongJie ZHANG GuangHui Li ZhengGui WEI XianZhu | 2018 | Science China(Technological Sciences)2018，61，11： | 5 |
| 13 | A Class of Fast Algorithms in Real-Time Simulation显示文摘A class of hybrid algorithms of real-time simulation based on evaluation of non-integerstep right-hand side function are presented in this paper. And some results of the convergence and stability of the algorithms are given. Using the class of algorithms, evaluation for the right-hand side function is needed once in every integration-step. Moreover, comparing with the other methods with the same amount of work, their numerical stability regions are larger and the method errors are smaller, and the numerical experiments show that the algorithms are very effective. | Zhu Zhenmin & Liu Degui(Beijing Institute of Computer Application and Simulation Technology, 100854, P. R. China)Li Shoufu(Mathematics Department of Xiangtan University, 411105, P. R. China) | 1999 | Journal of Systems Engineering and Electronics1999，10，4： | 4 |
| 14 | Dynamic simulation and optimization approach to construction diversion of hydraulic and hydroelectric projects显示文摘To solve the engineering and scientific problems in construction diversion and its simulation analysis, a complete scheme is presented. Firstly, the complex constraint relationship was analyzed among main buildings, diversion buildings and flow control. Secondly, the time-space relationship model of construction diversion system and the general block diagram-oriented simulation model of diversion process were set up. Then, the corresponding numerical simulation method and 3D dynamic visual simulation method were put forward. Further, the simulation and optimization platform of construction diversion control process was developed, integrated with simulation modeling, computation and visualization. Finally, these methods were applied to a practical project successfully, showing that the modeling process is convenient, the computation and the visual analysis can be coupled effectively, and the results conform to practical state. They provide new theoretical principles and technical measures for analyzing the control problems encountered in construction diversion of hydraulic and hydroelectric engineering under complex conditions. | ZHONG DengHua LI MingChao HUANG Wei LIU Yong | 2009 | Science China(Technological Sciences)2009，52，7： | 4 |
| 15 | Dynamic Analysis and Optimization of Pneumatic Wedge-Shaped Launcher for UAV显示文摘The constitution,structure,working principle and launching process of the wedge-shaped pneumatic launcher of an unmanned aerial vehicle(UAV)are described.By simplifying its physical model,two dynamic models of the UAV launch system are established based on Lagrange equation and MSC.ADAMS,respectively.The curves of the acceleration and the velocity of UAV changing with time are obtained.The simulation results are compared with the experimental results to verify the correctness of the model.Then,the influence of the parameters on the launch is explored.Finally,the system is optimized.The maximum overload and the acceleration fluctuation are reduced. | Huang Min He Cheng Pei Jinhua | 2018 | Transactions of Nanjing University of Aeronautics and Astronautics2018，35，5： | 4 |
| 16 | Novel Models and Algorithms of Load Balancing for Variable-structured Collaborative Simulation under HLA/RTI显示文摘High level architecture(HLA) is the open standard in the collaborative simulation field. Scholars have been paying close attention to theoretical research on and engineering applications of collaborative simulation based on HLA/RTI, which extends HLA in various aspects like functionality and efficiency. However, related study on the load balancing problem of HLA collaborative simulation is insufficient. Without load balancing, collaborative simulation under HLA/RTI may encounter performance reduction or even fatal errors. In this paper, load balancing is further divided into static problems and dynamic problems. A multi-objective model is established and the randomness of model parameters is taken into consideration for static load balancing, which makes the model more credible. The Monte Carlo based optimization algorithm(MCOA) is excogitated to gain static load balance. For dynamic load balancing, a new type of dynamic load balancing problem is put forward with regards to the variable-structured collaborative simulation under HLA/RTI. In order to minimize the influence against the running collaborative simulation, the ordinal optimization based algorithm(OOA) is devised to shorten the optimization time. Furthermore, the two algorithms are adopted in simulation experiments of different scenarios, which demonstrate their effectiveness and efficiency. An engineering experiment about collaborative simulation under HLA/RTI of high speed electricity multiple units(EMU) is also conducted to indentify credibility of the proposed models and supportive utility of MCOA and OOA to practical engineering systems. The proposed research ensures compatibility of traditional HLA, enhances the ability for assigning simulation loads onto computing units both statically and dynamically, improves the performance of collaborative simulation system and makes full use of the hardware resources. | YUE Yingchao FAN Wenhui XIAO Tianyuan MA Cheng | 2013 | Chinese Journal of Mechanical Engineering2013，26，4： | 4 |
| 17 | Numerical simulation of dynamic process ofthe Tangshan earthquake显示文摘IntrodnotionItisveryimportanttostudytheruptureprocessofewthquakefaultsforeathquakeengineering,earthquakeforecastingandreducingearthquakedisaster.Inversemethodandnumericalmethodareoftenusedtoinvestigatetheprobleminseismology.Theinversemethodisonthebas... | 蔡永恩 何涛 王仁 | 1999 | Acta Seismologica Sinica(English Edition)1999，12，5： | 4 |
| 18 | Numerical Investigation of the Aerodynamic Performance Affected by Spiral Inlet and Outlet in a Positive Displacement Blower显示文摘The flow in the positive displacement blower is very complex.The existing two-dimensional numerical simulation cannot provide the detailed flow information,especially flow characteristics along the axial direction,which is unfavorable to improve the performance of positive displacement blower.To investigate the effects of spiral inlet and outlet on the aerodynamic performance of positive displacement blower,three-dimensional unsteady flow characteristics in a three-lobe positive displacement blower with and without the spiral inlet and outlet are simulated by solving Navier-Stokes equations coupled with RNG k-ε turbulent model.In the numerical simulation,the dynamic mesh technique and overset mesh updating method are used.The computational results are compared with the experimental measurements on the variation of flow rate with the outlet pressure to verify the validity of the numerical method presented.The results show that the mass flow rate with the change of pressure is slightly affected by the application of spiral inlet and outlet,but the internal flow state is largely affected.In the exhaust region,the fluctuations of pressure,velocity and temperature as well as the average values of velocity are significantly reduced.This illustrates that the spiral outlet can effectively suppress the fluctuations of pressure,thus reducing reflux shock and energy dissipation.In the intake area,the average value of pressure,velocity and temperature are slightly declined,but the fluctuations of them are significantly reduced,indicating that the spiral inlet plays the role in making the flow more stable.The numerical results obtained reveal the three-dimensional flow characteristics of the positive displacement blower with spiral inlet and outlet,and provide useful reference to improve performance and empirical correction in the noise-reduction design of the positive displacement blowers. | LIU Xiaomin LU Jun GAO Renheng XI Guang | 2013 | Chinese Journal of Mechanical Engineering2013，26，5： | 4 |
| 19 | The surface velocity feature of Glacier No.1 at the headwater of Urumqi River,Tianshan Mountain显示文摘The movement of a glacier can redistribute glacier mass balance and change water and thermal conditions of the glacier.Thus,the glacier can maintain its dynamic balance.Surface velocity of a glacier is a basic feature of glacier movement.With successive monthly observations from 2006 to 2008,we obtained spatial and temporal variations for surface velocity of Glacier No.1 at the headwater of Urumqi River,Tianshan Mountain.Dynamic simulation was used to verify the findings.Results show that altitudinal distribution of glacier velocity was influenced by synthetic effects such as glacier thickness,slope,and bedrock morphology.However,seasonal variation was influenced by changing glacier thickness. | ZaiMing Zhou ZheFan Jing ShuHui Zhao TianDing Han ZhongQin Li | 2009 | Research in Cold and Arid Regions2009，1，6： | 3 |
| 20 | Effects of deformation parameters on microstructure and mechanical properties of magnesium alloy AZ31B显示文摘Plastic deformation and dynamic recrystallization (DRX) behaviors of magnesium alloy AZ31B during thermal compression and extrusion processes were studied. In addition, effects of deformation temperature and rates on the microstructure and mechanical properties were investigated. The results show that the DRX grains nucleate initially at the primary grain boundaries and the twin boundaries, and the twinning plays an important role in the grain refinement. The DRX grain size depends on the deformation temperature and strain rate The average grain size is only 1 μm when the strain rate is 5 s-1 and temperature is 250 ℃. It is also found that the DRX grain can grow up quickly at the elevated temperature. The microstructure of extruded rods was consisted of tiny equal-axis DRX grains and some elongated grains. The rods extruded slowly have tiny grains and exhibit good mechanical properties. | ZHANG Shaoming YANG Bicheng XU Jun SHI Likai CHEN Guoliang | 2006 | Rare Metals2006，25，z2： | 3 |
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