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International Conference on Artificial Intelligence, Management science and Electronic Commerce (AIMSEC)

作者： Gu Jinliang Hong'e Luo Zhou Liang Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology of PLA Nanjing Jiangsu China Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Nanjing Jiangsu China Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Jiangsu China JiangSu Broadcasting Corporation Broadcast Television Technology Center Nanjing Jiangsu China

This paper introduces a method of realizing fast projectile digital imaging and a process of digital image processing. Multi-exposure shadowgraphy, fast digital imaging, and acquisition and digital image processing technologies were employed to build a projectile fast imaging system. Through quick interpretation of the spatial coordinates of a projectile, measurement of the attitude angle and speed of a flying object was realized. With this system, high accuracy interpretation and computation of shadowgraphs can be performed quickly and accurately by those having less experience and a priori knowledge of shadowgraphs. By adopting multi-flash imaging technology, we can extract not only the attitude of a flying object but also information on speed, nutation, etc.

关键词： Projectiles Gray-scale Digital images Cameras Laser beams Fiber lasers

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Influences of the height of two wall-mounted rectangle cylinders on their Flow Patterns and Drag Coefficients

Influences of the height of two wall-mounted rectangle cylin...

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The 2011 International Conference on Mechanical Materials and Manufacturing Engineering(ICMMME 2011)

作者： Haiyuan Li Dawen Xue Zhihua Chen Baoming Li State Key Laboratory of Transient Physics Nanjing University of Science & Technology

Large eddy simulation has been applied to simulate the compressible flow past one and two wall-mounted rectangle cylinders, respectively. The dynamic subgrid stress model is employed to approximate the subgrid scale effects. Flow past one single wall-mounted cylinder is used as an example to validate our code. Flow past two wall-mounted cylinders is chosen for investigating the variation of flow fields and drag coefficients under different heights of two cylinders. Our numerical results show that, with certain ratio of two cylinder height, their drag coefficient can be improved, which is important for practical building industries.

关键词： large eddy simulation(LES) wall-mounted cylinder flow past cylinder drag force

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Property Adjusting of Magneto-Rheological Damper Using Neural Network Adaptive Filter

Property Adjusting of Magneto-Rheological Damper Using Neura...

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International Conference on Management and Service science, MASS

作者： Wei Wang Pin-Qi Xia Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology of PLA Nanjing China Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Nanjing China College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing China

Magneto-rheological (MR) damper is one kind of damping changeable component which output damping force can be controlled by input current under certain working condition. There are many models have been developed to predict MR damper's output include LMS force method which has been developed in our previous research. But most of model with unchangeable parameter which have been selected under certain condition in lab cannot adjust itself to adaptive actual working condition even under a small disturbance, such as temperature. To develop a method which can adapt different working condition, an adaptive filter has been studied based on neural network with BP update program. Furthermore to adjust MR damper's property to expected damping function, an adaptive inverse control method has been presented with the adaptive filter in this paper. The numerical simulation results indicate that the adaptive filter can fix the error introduced by varied working condition, the control precision of characteristic of magneto-rheological damper is better than phenomenon model, and the damping characteristic of MR damper can be controlled by using the adaptive inverse control method.

关键词： Shock absorbers Damping Force Adaptation models Adaptive filters Magnetomechanical effects Simulation

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The parallel algorithm study of cavitation flow on the hydrofoil

The parallel algorithm study of cavitation flow on the hydro...

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International Conference on Computer science and Service System (CSSS)

作者： Mu Zhang Junjie Tan Xinjian Ma Wenjun Yi Zhihua Chen School of Energy and Power Engineering Nanjing University of Science and Technology of PLA China Laboratory of Transient Physics Nanjing University of Science and Technology of PLA China

Since the numerical simulation for two phase flow that couples the cavitation model with turbulent flow, remains as one of the challenging issues in the society and needs a long calculation time to achieve the result. Hence, based on the shared-memory multiprocessor, a parallel algorithm is designed to reduce the calculation time in this paper. The LES technology and Sauer cavitation model are used to simulate the cavitation flow on the hydrofoil. A divisional method is designed to implement the load balance. A case of NACA0015 hydrofoil is adopted to validate the parallel algorithm. Furthermore, the speedup ratio and parallel efficiency are investigated. Comparison of the parallel calculation result with the experiment result and the serial calculation result, it's shown that the parallel algorithm can be applied to the simulation of cavitation flow.

关键词： Parallel algorithms Mathematical model Simulation Equations Numerical models Computational modeling Numerical simulation

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Experimental and numerical study on the penetration performance of nanocrystalline copper shaped charge jet

Experimental and numerical study on the penetration performa...

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第十届全国冲击动力学讨论会

作者： Jinxiang Wang Zhenyong Xu Nan Zhou Rui Yang Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Shandong Luzhong Steel&Iron Logistics Co. Ltd Laiwu 271104 China

The penetration performance of nanocrystalline as well as coarse-grained copper shaped charge jets was studied by experiments under the offset distance from twice to four times diameter of the shaped charges Dynamic mechanical property of copper specimen with different average grain size at high strain rates from 1700 to 6800 s-1 was tested by *** split Hopkinson pressure bar(SHPB) and the Johnson-cook constitutive parameters were obtained. Penetration process of the shaped charge jets on the targets was calculated by LS-Dyna finite element program to analyze the penetration mechanism. The results show that the penetration performance of the NC copper shaped charge jets are superior to that of the coarse-grained copper shaped charge jets by 6.7-11.7 percent due to the super plasticity of the jets.

关键词：纳米铜渗透性能数值模拟动态力学

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A useful Doppler Radar outlier elimination algorithm Based on Orthogonality of Innovation

A useful Doppler Radar outlier elimination algorithm Based o...

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第八届IEEE信息与自动化国际会议(ICIC 2011)

作者： Hongyang BAI Xiaozhong XUE National Key Laboratory of Transient Physics Nanjing University of Science and Technology Nanjing Ji Department of Power Engineering Nanjing University of Science and Technology Nanjing Jiangsu China

In order to solve the problem that the precision and stability of Doppler radar/Fiber Optical Gyroscope Strapdown Inertial Naivgation System(FOG-SINS)/Barometer Integrated Navigation System(DFBINS)for helicopters will be highly affected if there are outliers in doppler radar,especially consecutive outliers appear,a useful method to eliminate these outliers based on orthogonality of innovation is proposed in this *** in Doppler radar can be detected by judging whether the orthogonality of innovation in Kalman filter is lost or not,and an activation function as the weight factor to each element of observation is assigned,so it can keep innovation sequence of kalman filter orthogonal and outliers can be detected and *** excellent results of digital simulation for a long distance straight line flying test show that the modified method is effectively resistant to the adverse effects on accuracy and stability of DFBINS caused by outliers in Doppler radar,the proposed algorithm is of high value in practice.

关键词： Doppler radar Kalman filters Technological innovation Aircraft navigation Helicopters Mathematical model

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Experiment and numerical simulation for penetration performance of nanocrystalline copper shaped charge jet

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Binggong Xuebao/Acta Armamentarii 2011年第SUPPL. 2期32卷 350-354页

作者： Wang, Jin-Xiang Xu, Zhen-Yong Zhou, Nan Yang, Rui Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Nanjing 210094 Jiangsu China Shandong Luzhong Steel and Iron Logistics Co. Ltd. Laiwu 271104 Shandong China

To analyze the influence of grain size on the penetration performance of shaped charge jets, the nanocrystalline and coarse-grained copper shaped charges were compared experimentally under different offset distances from two to four times of the charge diameter. The dynamic mechanical properties of copper specimens with different grain sizes were tested at high strain rates from 1700 s-1 to 6800 s-1 by using φ14.5 mm split Hopkinson pressure bar (SHPB), and Johnson-Cook constitutive model parameters were obtained. The penetration process of the shaped charge jet on the targets was calculated by LS-Dyna finite element program to analyze the penetration mechanism. The results show that the penetration performance of NC copper shaped charge are superior to that of the coarse-grained copper shaped charge by 6.7%-11.7% due to the super plasticity of their jets at high strain rate.

关键词： Copper

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Holographic interfermetry based on fulgide film

Holographic interfermetry based on fulgide film

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2011 International Conference on Electronics and Optoelectronics, ICEOE 2011

作者： Ji, Ke Menke, Neimule Yao, Baoli Wang, Yingli Chen, Yi School of Physical Science and Technology Inner Mongolia Universtiy Huhhot 010021 China State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'an 710068 China Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100101 China

ISBN: (纸本)9781612842738

Holographic interfermetry was realized in a 3-indoly-benzylfulgimide/ PMMA film by using double exposure method and single exposure method for the first time. The structures of an optical wedge and an optical axicon, the rotation angle of the optical wedge and the movement distance of the optical axicon were successfully measured. It is proved that fulgide films can be used as recording medium in holographic interfermetry. As a recording medium in holographic interfermetry, the 3-indoly-benzylfulgimide/PMMA films have many advantages such as low cost, easy to use, rewritable, long life time, and higher signal to noise ratio (with small particles) and higher sensitivity etc. Then using the photoinduced anisotropy property of the 3-indoly-benzylfulgimide/PMMA film, the polarization multiplexing holographic interfermetry was realized, which can be used in particle field's dynamic measurement. This method is told for the first time, and it is proved that using this method, not only the size but also the directions of the objects' movement velocities can be got. © 2011 IEEE.

关键词： Polarization

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The analysis on the powerful devices in pulsed power supplies

The analysis on the powerful devices in pulsed power supplie...

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International Conference on Mechanic Automation and Control Engineering (MACE)

作者： Jinliang Gu Honge Luo Yan Xia Zhenxiao Li Yude Zhu Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology of PLA Nanjing Jiangsu China Technical Development Department Hubei TECH Semiconductors CompanyLimited XiangYang Hubei China

ISBN: (纸本)9781424494361

In the capacitor-based pulsed power supplies (PPS), the tabulate thyristor combination is usually used as the powerful discharge switch, and tabulate rectifier diode combination as the crowbar diode. Based on discuss of the discharge process of the PPS, emphasize on analysis of the invalidation example of the powerful devices then the method how to choose parameters of the powerful devices in PPS was given. The results of experiments on the multiple modules show that the parameter choice method is practical and valuable.

关键词： Thyristors Semiconductor diodes Power supplies Discharges transient analysis physics Switches

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The application of parallel computation to the compressible turbulence with LES

The application of parallel computation to the compressible ...

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International Conference on Computer science and Service System (CSSS)

作者： Wanglong Zhang Junjie Tan Dengfeng Ren Zhihua Chen Wenjun Yi School of Energy and Power Engineering Nanjing University of Science and Technology of PLA Nanjing Jiangsu China Laboratory of Transient Physics Nanjing University of Science and Technology of PLA Nanjing Jiangsu China

Parallel computation of the compressible turbulence with LES was performed with computational fluid dynamics. The Message Passing Interface (MPI) parallel environment was constructed based on Linux OS, and the corresponding parallel computational program with LES was developed by adopting the C Language. The approximate Reimann solver and two-step Runge-Kutta time-advance were adopted to solve the Favre-filtered N-S equations. The computational domain was partitioned uniformly into several sub-domains based on multi slave model and the load balance, to improve the parallel computational efficiency. And then the comparison of parallel speedup, parallel efficiency under kinds of dividing-domain methods was done. The numerical results show that the parallel computational program and method are acceptable, and could be further applied to the computation of the more complex turbulence.

关键词： Computational modeling Mathematical model Stress Fluids Numerical models Equations Libraries

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