Table of Content

23 May 2014, Volume 35 Issue 5

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Paper

Optimal Design of Bus-type Voltage Acquisition System

MA Xiao-jun, KE Rong-shuo, WEI Shu-guang, XIANG Yu, ZENG Qing-han

2014, 35(5):  577-582.  doi:10.3969/j.issn.1000-1093.2014.05.001

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Power supply system, such as power battery pack and fuel cell,normally uses a series-type power supply structure, and the voltage parameter of battery is an important performance index of the battery. A bus-type voltage acquisition system is designed. In the system, the photoelectric relay is adopted to load a battery on the measurement bus, and the voltage monitoring is implemented by means of the logic control of shift register 74HC164. Thus the consistency of the overall measurement is improved through single signal processing and isolation circuit. The number of components is reduced, and the circuit structure and control procedure are optimized compared to logic circuit with decoder. The modularization and scalability of the measurement system are achieved by PIC18F2580 minimum system and CAN bus interface. The experimental result shows that the system has stable performance and meets the requirement of measuring accuracy, which has been used for the voltage monitoring of 3 kW and 10 kW fuel cells.

Adaption of Fuel Injection Parameters for Turbocharged Diesel Engines Working at High Altitude

ZHU Zhen-xia, ZHANG Fu-jun, HAN Kai, LIU Yang-yang, LUO Guo-liang, LI Yun-long, CHAI Zhi-gang

2014, 35(5):  583-589.  doi:10.3969/j.issn.1000-1093.2014.05.002

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In order to enhance the performance of turbocharged diesel engine at a high altitude, three different schemes are compared by virtue of simulation. The effectiveness of the method to enhance the power of engine at a high altitude is verified by adjusting the fuel supply parameters without modifying the engine structures or adding any accessories. A model for a V6 turbocharged engine equipped with a new compressor is established for the highland simulation. And then the model is certified by experimental data. The influence of fuel injection advance angle on the power, the turbine intake temperature and the maximum combustion pressure is investigated. Based on the research results, the detailed methods to adjust the fuel supply parameters are put forward. Three different simulating schemes are calculated and compared through simulation. The result shows that the rated power of engine at the altitude of 4 500 m can reach up to 75% of its counterpart by using this method to adjust the injecting timing and fuel injection.

Optimization Design and Analysis of High Speed Wet Proportional Solenoid Valve

MENG Fei， TAO Gang， ZHANG Mei-rong， CHEN Hui-yan

2014, 35(5):  590-596.  doi:10.3969/j.issn.1000-1093.2014.05.003

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The design and optimization method for the key parameters of proportional solenoid valve used for automatic transmissions are explored. The operating principle of valve is investigated based on the structural analysis. The proportional solenoid valve is divided into 3 components, including electro-magnet, mechanical component, and hydraulic component. The mathematical models for the three components are built separately, and the key factors which influence its response time and pressure dynamic output are analyzed. The optimization design of electro-mechanical converter is performed. The relationship between electromagnetic force and input current is determined, and the genetic algorithm is used to optimize and analyze the proportional solenoid valve by taking the valve mass, spring stiffness, initial compression of spring and viscous damping coefficient as optimized parameters, and the response time and overshoot of output pressure as optimized object. Several structure schemes of proportional solenoid valve are obtained by changing the scope of population, the number of the generation, the crossing-over rate and the mutation rate. The research results show that the dynamic response of output is improved by 12.5%，and the overshoot of output pressure is decreased by 50% after optimization.

Active Disturbance Rejection Control for Position Servo System of Rocket Launcher

ZHENG Ying， MA Da-wei， YAO Jian-yong， HU Jian

2014, 35(5):  597-603.  doi:10.3969/j.issn.1000-1093.2014.05.004

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The strong disturbance of combustion gas flow and the large change of system parameters for rocket launcher are analyzed. The system model is based on real servo system with speed closed loop using frequency domain analysis. The approximate low frequency and middle frequency models are established to construct the second-order and third-order linear extended state observers for position servo system. And the active disturbance rejection control methods are designed to estimate the uncertain dynamics compensating the input control. The control effects of proposed control laws and traditional PID are compared both in the servo tracking and the disturbance of combustion gas flow. The simulation results indicate that the proposed methods can effectively improve the output tracking accuracy, and restrain the vibration of launching platform resulted from the disturbance of combustion gas flow to maintain hit precision of projectile.

Penetration Depth Calculation Model for Biconical Liner Jet Penetrating into Steel Target

CHEN Chuang， WANG Xiao-ming， LI Wen-bin， LI Wei-bing， WU Cheng

2014, 35(5):  604-612.  doi:10.3969/j.issn.1000-1093.2014.05.005

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In order to describe the whole process of biconical liner jet penetrating into steel target, Bernoulli equation is modified by using shock wave Hugoniot relationship. Double virtual origin is deduced by combining the improved PER theory, and then a penetration depth theoretical model is established by considering the factors of shock wave, jet velocity distribution and jet state. The accuracy of forecasting the penetration depth is improved using the calculation models of shock wave, double virtual origin and jet fracture effect. The influences of demarcation points on penetration depth are compared, and the rules of stand-off distance and biconical liner structural parameters influencing the penetration depth are obtained. The results show that the demarcation point of continuous and break-up jets occurs earlier than the demarcation point of shock wave effect with the increase in stand-off distance. Moreover, the tip velocity, inflection velocity and penetration depth decrease with the increase in top cone angle. But with the increase in height radio of top cone, the tip velocity and penetration depth increase gradually, and the inflection velocity exhibits a descendant trend.

A New Ranging Method for FMCW Fuze Based on the Ratio of the Derivation

XIANG Cheng-yong, PAN Xi, WANG Zheng-hao, WANG Fang-zhou

2014, 35(5):  613-619.  doi:10.3969/j.issn.1000-1093.2014.05.006

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Frequency modulation continuous wave (FMCW) fuze has the advantages of low probability of intercept and high ranging accuracy. The traditional harmonic detection algorithm used for FMCW fuze has the inherent error, which is inversely proportional to the frequency offset. And the computing amount of FFT method used for the short range frequency modulated radar is huge, and the hardware is not easy to implement in low cost application. A new algorithm based on the derivative ratio is proposed to reduce the error without increasing the frequency offset. Furthermore, owing to the severe requirement related to the volume and cost of traditional fuze, the new method has the advantage of small amount of computation and high real-time performance, which makes it more implementable in low-cost hardware such as the single chip microcomputer (SCM).

Research on Rotation Characteristics and Cavitation of Underwater Turbine at Small Attack Angle

CHEN Yong, ZHANG He, MA Shao-jie, SHEN De-zhang

2014, 35(5):  620-626.  doi:10.3969/j.issn.1000-1093.2014.05.007

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The rotation of turbine at small attack angle is theoretically analyzed in order to obtain the rotation characteristics of a turbine in front of an underwater fuze at small attack angle, and the simulation models and an experimental program are created. On this basis, the turbine speed at flow velocity of 0 m/s~ 35 m/s is obtained at 0° and 5°attack angles. For the non-cavitation and the cavitation number from 0.2 to 1.0, the corresponding characteristics of the turbine rotation and cavitation at 10m/s are analyzed by comparing the simulation and experimental results at 0° and 5°attack angles. The results show that the simulation and experimental results are basically consistent and well predict the turbine characteristics. Compared with 0°attack angle, the turbine speed at 5° attack angle becomes higher at lower flow velocity and vice versa; under cavitation, the periodical change of original speed signal of turbine disappears at 5°attack angle, and the turbine stalls in the case of lower cavitation number.

Parameter Extraction Technique Based on Periodic Ambiguity for PRCPM-SFM Compound Fuze Signal

ZHANG Shu-ning， ZHU Hang， ZHAO Hui-chang， LIU Jing

2014, 35(5):  627-633.  doi:10.3969/j.issn.1000-1093.2014.05.008

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Feature parameter extraction of pseudo-random code phase modulation and sine frequency modulation (PRCPM-SFM) compound fuze signal is a precondition for deception jamming. The periodic ambiguity of PRCPM-SFM signal is analyzed for the PRCPM-SFM fuze detection signal in noise. The noise reduction mechanism based on periodic ambiguity is studied. Based on the characteristic of periodic ambiguity of fuze signal, the parameter extraction algorithm in ambiguity transform domain is designed. Simulation proves that the method can extract the feature parameters effectively and has good anti-noise ability.

CMOS-compatible High-Q Micro-electro-mechanical System Suspended on-chip Spiral Inductor

LU Chong-ying， XU Li-xin， LI Jian-hua， FU Bo， OU Xiu-long

2014, 35(5):  634-639.  doi:10.3969/j.issn.1000-1093.2014.05.009

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A COMS-compatible high Q-factor suspended on-chip spiral inductor used in the radio frequency front-end of radio fuze is designed and fabricated using the micro-electro-mechanical system (MEMS) surface-micromachining technology. The fabrication process of inductor is compatible with CMOS in the aspects of both thermal budget and materials. The loss factors of on-chip spiral inductor are reduced by using a suspended copper coil, and the Q-factor is significantly improved. The improved inductor model is analyzed by the electromagnetic finite element analysis software HFSS. The MEMS suspended on-chip inductor is measured. The measurement results show that the Q-factor of inductor is more than 20 in the frequency range of 1～7.6 GHz and reaches 38 at 7.4 GHz.

Research on Ignition and Combustion Properties of Different Micro/nano-aluminum Powders

LI Xin, ZHAO Feng-qi, HAO Hai-xia, LUO Yang, XU Si-yu, YAO Er-gang, LI Na

2014, 35(5):  640-647.  doi:10.3969/j.issn.1000-1093.2014.05.010

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Micro/nano-aluminum powders have extensive application prospect in the field of explosives and propellants. In order to reveal the combustion mechanism of micro/nano-aluminum powders in propellants, the ignition and combustion properties of different types of micro/nano aluminum powders are studied by CO₂ laser ignition device. The results show that ignition and combustion properties of micro/nano-aluminum powders are better than those of the nano-aluminum powders. Ignition delay time of 80nm aluminum powder is longer than that of 120 nm aluminum powder, which is caused by the decrease in the internal and external pressures because of the reduction in active aluminum content. Ignition and combustion mechanisms of micro/nano aluminum powders are analyzed. The ignition and combustion properties of micro-aluminum powders after surface modification by nickel nanopowders are improved, and the nickel nanoparticles are treated as the carrier of oxygen. Ignition delay time of aluminum nanoparticles coated with organic matter is increased. However, they could prevent the aluminum nanopowders from oxidating and enhance the energy performance. The energetic polymer is still seen to be well done in the surface coating of aluminum nanopowders.

Design of Cooled LWIR Refractive/diffractive Athermal Telephoto Objective

ZHANG Yu, WANG Wen-sheng

2014, 35(5):  648-653.  doi:10.3969/j.issn.1000-1093.2014.05.011

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According to the overall design requirement of tank infrared observing-aiming system, a cooled LWIR refractive/diffractive athermal telephoto objective is designed in order to meet the requirements of infrared target detection in battlefield environments. The telephoto objective is composed of objective and relay lens. The focal length is -200 mm, the F number is 2.1, and the full field of view is 3.6°. The detector is the MARS-VLW LWIR focal plane array produced by Sofradir Company. Its resolution is 320× 256 pixels, and the pixel size is 30 μm×30 μm. The image quality of this telephoto objective is excellent. In the temperature range of -40 ℃~60 ℃, MTF of each field of view is about 0.5 at the cutoff frequency of 17 cy/mm, the root mean square radius of spot diagram for each field of view is much smaller than the Airy spot radius (34.5 μm). The cold-shield efficiency is 100%. This infrared telephoto objective can be used for other infrared observing-aiming system.

A Block Compressed Sensing Method Based on Multi-element Detector Array

ZHANG Zhi-quan， DING Sheng， JIN Wei-qi

2014, 35(5):  654-661.  doi:10.3969/j.issn.1000-1093.2014.05.012

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A block compressed sensing method is proposed considering that the calculation time of image reconstruction increases rapidly with the image size when compressive sensing (CS) theory is applied in single-pixel imaging. In the method, a digital micro-mirror device (DMD) and a multi-element detector array are used for encoding and measuring, and a total variation minimization method is used for image reconstruction, where the peak signal-to-noise ratio (PSNR) and the structural similarity (SSIM) of recovered images are improved by using gray stretch technique. Simulation results show that the method has the characteristics of shorter calculation time and higher recovered image quality. For 16 image blocks, the calculation time can be shorten by 40% at least. The PSNR and mean SSIM values of recovered images can be improved by 70% and 11%, respectively, through gray stretching of image blocks.

Research on an Extended Optimal Guidance Law with Multiple Constraints

WEN Qiu-qiu, LIU Da-wei, XIA Qun-li, LI Ran

2014, 35(5):  662-669.  doi:10.3969/j.issn.1000-1093.2014.05.013

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An extended optimal guidance law with terminal miss distance and impact angle constrains is derived. The guidance law is obtained as the solution of a linear quadratic optimal control problem with the goal function weighted by a power of the time-to-go. Based on the analytical expression for the change of guidance command with time and the adjoint system analysis method, the command characteristics and dimensionless miss distance of guidance law are analyzed. The result shows that the acceleration command of guidance law can be converged into zero in the final time of guidance, which may create a good situation for terminal angle of attack control. A design principle for selection of guidance law gain is discussed. Finally, according to the requirements of engineering application, the methods on calculating the guidance initial condition and maximal required acceleration are given. The effectiveness and practicality of the guidance law are demonstrated through simulation.

Research on Variation Mechanism of Additional Load of Adaptive Base during Drape Ejection

REN Jie， MA Da-wei， ZHONG Jian-lin

2014, 35(5):  670-675.  doi:10.3969/j.issn.1000-1093.2014.05.014

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To research the formation and variation mechanism of the additional load, a mathematical model of the additional load is established, and the differential and integral formula of additional load are derived. The main factors which affect the additional load are obtained, such as pressure in adaptive base, horizontal projected area of upper face, and horizontal projected area of touchdown zone. The theoretical formula of additional load is verified by the numerical model. The analytical solution is well consistent with the numerical solution, and the relevant error is less than 1.9%. The relationship between the integral area and the expression form of the additional load is studied according to the integral formula of the additional load. The results indicate that there exists corresponding relationship between the direction of the additional load and the kind of the integral area, and that situation of that the direction is opposite in some areas may happen. When the ground subsidence is small or the shear failure exists in some area, the additional load may stays the same. When the ground subsidence is large, the amplitude and direction of the additional load may change.

Research on Dynamic Performance of Superfluid Gyroscope

ZHENG Rui, ZHAO Wei, LIU Jian-ye, NIE Wei, CHENG Qing

2014, 35(5):  676-680.  doi:10.3969/j.issn.1000-1093.2014.05.015

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In order to research the dynamic performance of a novel superfluid gyroscope, the factors which have effect on the detectable angular acceleration of gyroscope are analyzed. Based on the mathematic model of Josephson frequency for thermal driving, the detectable angular acceleration of gyroscope is simulated. The results show that, according to common parameters, the maximal value of detectable angular acceleration is about 0.32 rad/s², so the dynamic performance of superfluid gyroscope is small. The gyroscope can be used for the field which requires the higher detection accuracy and slow change of angular velocity.

Modeling of IR Seeker for Air-to-air Missile and Anti-interference Simulation

CHAI Shi-jie，LI Jian-xun，TONG Zhong-xiang，FAN Xiao-guang，ZHUO Zhen-fu，CONG Wei

2014, 35(5):  681-690.  doi:10.3969/j.issn.1000-1093.2014.05.016

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For the simulation demands of fighter’s combat and training on IR attack-defend countermeasure, the whole attack process of multi-unit IR guided missile is simulated. A target identification algorithm based on time domain waveform characteristics is proposed, which makes the creditability of missile simulation results improved. Anti-interference technique of missile is analyzed. A missile universal motion and guidance model is established through velocity graph and practicable over-loading, which not only simplifies the operation but increases the precision. At last, the attack region of a missile under typical assault conditions is calculated. The simulation result shows that the characteristics of fast generated attack area agrees well with characteristics of real attack area.

The Effect of Entrance Airflow Parameters on Solid Fuel Scramjet Combustor Performance

WANG Li-he, WU Zhi-wen, LIU Chang-xiu, TAO Huan, WEI Zhi-jun, WANG Ning-fei

2014, 35(5):  691-696.  doi:10.3969/j.issn.1000-1093.2014.05.017

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In order to study the effect of entrance airflow parameters on the performance of combustor, a solid fuel regression rate model is coupled to the quasi-one-dimensional flow equations, and a quasi-one-dimensional method of combustor design and analysis is proposed. The method is used to keep the parameters of flight environment invariable and change the the total pressure, total temperature and mach number at the entrance of combustor. The sizes and performance of combustor under different flow conditions are calculated by using the quasi-one dimensional design and analysis method. The result shows that the total pressure and total temperature of entrance airflow can be increased to improve the performance of combustor under the design flight condition, but the influence of the total temperature on its performance is more greater. Lower mach number can be used to reduce the heating loss and improve the performance of combustor. If the air mass flow rate and the step area ratio are constant, the total temperature and total pressure are increased and the Mach number is reduced to improve the fuel regression rate and reduce the combustion chamber length.

Real Time Ultrasonic Monitoring of Curing State of Liner in Solid Rocket Engine

YANG Ya-jun, WANG Zhao-ba

2014, 35(5):  697-702.  doi:10.3969/j.issn.1000-1093.2014.05.018

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The ultrasonic longitudinal wave reflection technology and the laser thickness measurement technology are used to monitor the curing process of solid rocket engine liner. An ultrasonic system is designed to monitor the curing process of liner in real-time to meet the need of using common ultrasonic probe under the curing temperature. The curing state of liner is characterized by the changes of liner thickness, ultrasonic longitudinal wave velocity and acoustic attenuation coefficient. The experimental results show that the liner thickness and acoustic attenuation coefficient decrease and the propagation velocity of longitudinal wave increases gradually during the curing reaction of liner, which reflects the change in curing state of liner, and its “half curing” state can be determined.

Research on Energy Dissipation and Fractal Characteristics of Concrete after Exposure to Elevated Temperatures underImpact Loading

SHI Jin-song, XU Jin-yu， REN Wei-bo， SU Hao-yang

2014, 35(5):  703-710.  doi:10.3969/j.issn.1000-1093.2014.05.019

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The energy dissipation capacities and fragments distribution of concrete exposed to high temperature under impact loading are studied. Dynamic compressive tests of concrete at room temperature and after exposure to elevated temperatures ranging from 200 to 800 ℃ are conducted by using a split Hopkinson pressure bar with 100 mm in diameter. The effects of high temperature and impact velocity on dissipated energy, failure mode and fractal dimension of fragments are analyzed. The results indicate that the dissipated energy grows with the increase in impact velocity and strain rate at the same temperature; and at fixed impact velocity, the dissipated energy decreases with the increase in the exposure temperature. The fragment-size distribution of concrete fragments statistically has fractal property subjected to impact loading. An increase in temperature and impact velocity results in a greater crushing degree and a larger fractal dimension value. There is a positive correlation between dissipated energy and fractal dimension at the same temperature. As a result, the impact crushing of concrete at various temperatures and impact velocities is a fractal evolution process driven by external energy.

Research on the Unsteady Characteristics of Ventilated Cavitating Flows in the Form of Gas-leakage by Toroidal Vortex

DUAN Lei, WANG Guo-yu, FU Xi-neng

2014, 35(5):  711-718.  doi:10.3969/j.issn.1000-1093.2014.05.020

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To understand the unsteady characteristics of ventilated cavitation in the form of gas-leakage by toroidal vortex，the ventilated cavitating flows around axisymmetric body are researched by the experimental and numerical methods. A filter-based turbulence model is used in numerical simulation in order to accurately capture the vortex separation. In experiment, the high-speed video camera is used to observe the flow structure. The results show that the numerical results are consistent with the experimental results. The unsteady ventilated cavitating flow is the shedding process of cloud bubble in the rear of ventilated cavity. Flow separation in the region of ventilated cavity is caused by adverse pressure gradient, resulting in a complex vortex structure. An interaction between vortex structure and the main flow leads to the cloud bubble shedding in the rear of ventilated cavity.

An Optimization Model of Wartime Spare Parts Resource Allocation on Consideration of Maintainability

WANG Zheng-yuan, CAO Ji-ping, ZHU Yu, ZHU Ya-hong

2014, 35(5):  719-724.  doi:10.3969/j.issn.1000-1093.2014.05.021

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Research on spare parts resource allocation in wartime has an important significance to win a war. An optimization model of wartime spare parts allocation is built up, in which weapon damage, fault equipment repair capacity and mission time are taken into comprehensive consideration. The solution of the model is put forward, and the optimal allocation of spare parts resources is achieved. It is found that the influence factors of wartime spare parts resource allocation are mainly reliability of weapons and equipment, suffered damage, combat task timeliness and repair capacity of fault equipment. The experimental results show that the method proposed here can effectively reduce the supply of spare part resources, and can ensure the operational task to be completed in a given time window under the certain conditions.

Comprehensive Review

Research Progress in Synthesis of Hexanitrohexaazaisowurtzitane2*3/4〗PANG Si-pingSHEN Fan-fanLYU PENG-haoDONG KaiZHANG Yi-yingSUN Cheng-huiSONG Jian-weiZHAO Xin-qi (725)Research NotesScale Model and Model Experiment of Electromagnetic Coil Launcher

PANG Si-ping, SHEN Fan-fan, LYU PENG-hao, DONG Kai, ZHANG Yi-ying,

2014, 35(5):  725-732.  doi:10.3969/j.issn.1000-1093.2014.05.022

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The progress in synthesis and engineering manufacture of high energy and density compound hexanitro-hexaazaisowurtzitane (HNIW or CL-20) is reviewed. The advantages, drawbacks and applications of three main approaches to the engineering manufacture of CL-20 based on hexabenzylhexaazaisowurtzitane(HBIW) intermediate are discussed, the difficulty in developing new synthetic routes for CL-20 is also analyzed. The result shows that the synthesis and nitration efficiencies of the new isosowurtzitane precursor are low, and its cage-dimensional structure is easily broken. The developing tends on lowering CL-20 production cost is to seek new efficient catalysts and explore new synthesis routes.

Research Notes

Research on the Influence of Different Automatic Action of Gun on Its Recoil Effect in Man-gun System

ZOU Ben-gui， SUN Xue-feng， CAO Yan-jie， TAN Le-zu， ZENG Jia-you

2014, 35(5):  733-740.  doi:10.3969/j.issn.1000-1093.2014.05.023

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Model experiment is an effective method to investigate the working process of electromagnetic coil launcher (EMCL). The model experiment results are used for prototype study of EMCL after the scaling factor relations of the physical parameters of model and prototype are mastered. Based on mathematical model of EMCL and similarity theory, the requirements for designing the model of EMCL are derived. The scaling model is researched by simulation. The experiment verification of the single-stage EMCL is conducted. The simulation of EMCL and experimental results show that the scaling factor relations of physical parameters are expressed as functions of the length scale factor. The working characteristics of EMCL sub-scale model can be deduced if the structure parameters of EMCL prototype and the length scale factors are given, and vice versa. The research results lay the theoretic foundation for model experiment.

Analysis and Implementation of Rife-based Ranging Algorithm for Linear Frequency Modulated Continuous Wave Radar

WANG Chang-geng， XU Wan-he， XU Cheng

2014, 35(5):  741-747.  doi:10.3969/j.issn.1000-1093.2014.05.024

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In order to study the characteristics and influence factors of recoil effect of gun in the man-gun system, two dynamic models for the recoil effects of gas-operated and simple blowback bolt type guns for firing at the standing position are established in consideration of man-gun interaction. The models are based on gun interior ballistic properties, recoil mechanism and bolt movement in different automatic ways, rigid-body dynamics and collision dynamics. The gun recoil force, recoil velocity and shoulder horizontal displacement in man-gun system are numerically and experimentally analyzed. The research results show that the rules of the changes of gun recoil force and the shooter' recoil velocity and displacement withe recoiling time, and the number of occurrences and time of the maximum are not same for two different kinds of automatic gun.