Table of Content

29 November 2008, Volume 29 Issue 11

Previous Issue    Next Issue

Paper

The Application of Computational Fluid Dynamics in Design ot the Vehicle Cooling Wind Tunnel

HUANG Xiao-hui, BI Xiaoping

2008, 29(11):  1281-1285.  doi:10.3969/j.issn.1000-1093.2008.11.001

Asbtract ( )   PDF (5504KB) ( )  

References | Related Articles | Metrics

A CFD calculation model for the computation of airflow and heat transfer in an armored ve?hicle cooling wind tunnel is established. A utility method on determining computation region outside power train compartment and on producing mesh step that ensure adequate grid mass is put forward. A 3-D numerical value is solved by using commercial software Fluent. Precision of the CFD calculated re?sults is verified. By applying the CFD to design of the vehicle cooling wind tunnel, air flow resistance of fan lead stream board is calculated, and the good effect of the CFD method in design of wind tunnel is achieved.

The Fuzzy Logic Control for Suspension Systems of Tracked Vehicles

YU Yang, WEI Xue-xia, ZHANG Yong-fa

2008, 29(11):  1286-1291.  doi:10.3969/j.issn.1000-1093.2008.11.002

Asbtract ( )   PDF (6048KB) ( )  

References | Related Articles | Metrics

A scheme of fuzzy logic control for suspension systems of tracked vehicles was presented ? A mechanical model for a half of a tracked vehicle was established, which is totally eight degrees of free?dom including the vertical motion and rotation of the tracked vehicle. In contrast to most previous studies, the coupling effect between the vertical and rotational motions of suspension system of the tracked vehicle was considered. In addition, the different combinations of control forces were investi?gated, and a theoretical limit for the rotation control was discovered. The simulation of fuzzy logic con?trol under road surfaces of sine and random excitation shows that the acceleration and pitch angle of suspension system can be controlled efnciently.

Experimental Study on the Knock Control of HCCI Engine by Ferrocene at High Loads

HE Chao, JI Chang-wei

2008, 29(11):  1292-1295.  doi:10.3969/j.issn.1000-1093.2008.11.003

Asbtract ( )   PDF (4316KB) ( )  

References | Related Articles | Metrics

The effect of ferrocene additive on high load knock of homogeneous charge compression igni?tion (HCCI) engine was investigated by an experiment carried out with the fourth cylinder of a four- cylinder diesel engine. The experimental results indicate that ferrocene can restrain the HCCI engine knock and extend the HCCI operational load range; at the ferrocene mass fraction of 0.000 25, the knock is abated and the load range is enlarged a little; when the ferrocene mass fraction increases to 0.000 3d and 0.000 5, the knock and the load range are improved a lot, but higher ferrocene fraction resulted in more likely engine misfire; the optimal mass fraction of ferrocene is 0.000 35 at I 400 r/min.

The Utmost Shooting Boundary Analysis of Cannon Fire Against any Velocity Target

WEI Chaoyang, ZANG Wen-li, JIANG Jin-long

2008, 29(11):  1296-1302.  doi:10.3969/j.issn.1000-1093.2008.11.004

Asbtract ( )   PDF (5828KB) ( )  

References | Related Articles | Metrics

It was interpreted and testified that the moving velocity of the lead point tracked by gun-tar?get line has a limited value in the case of arbitrarily high velocity of approaching target; the region, in which the gun can track and shoot arbitrary velocity target, exists; the shooting time not restricted by the target velocity exists in the mentioned above region. The tracking angular velocity and the firing rate are no longer a main restricted factors of the shooting ability of cannon when they reach a certain extent.

Influence of Metal Lining on the Composite Material Barrel Thermal Performance

CHEN Long-miao, QIAN Lin-fang

2008, 29(11):  1303-1307.  doi:10.3969/j.issn.1000-1093.2008.11.005

Asbtract ( )   PDF (5259KB) ( )  

References | Related Articles | Metrics

The pure metal tube weight is reduced and its stiffness is improved by fiber reinforced com?posite material wound on metal liner. In order to analyze the influence of metal lining on the composite material barrel thermal performance in detail, the heat rransfer numerical model of the barrel at launching transient was established by finite difference method, and the influence was analyzed numer?ically and quantitatively by programmed general program based on several barrel design projects. The analyzed result shows that the metal lining thickness has great influence on the heat transfer perfor?mance; the thicker the metal lining is the more favourable the performance is, but which is un?favourable for lightening the weight; therefore the thickness should be considered in integrated opti?mization design emphatically.

Finite Element Analysis and Its Application for the Linear Buffer in Charge Pressing System

LIU Feng-lin, WANG Ji-ning, LIU Rong

2008, 29(11):  1308-1314.  doi:10.3969/j.issn.1000-1093.2008.11.006

Asbtract ( )   PDF (6113KB) ( )  

References | Related Articles | Metrics

In view of the serious nonlinear and creep problems of pressure controlling during charge pressing process of pyrotechnics, a special linear buffer with simple structure was proposed to improve its process performance. To analyze various characters of the linear buffer, its finite element stress analysis model was established, the static load intensities and the yielding limits of the different geo?metric character linear buffers were numerically simulated by the model. According to results of the analysis, the relationship between geometrical character and stiffness of the buffer was obtained, and the partial experiments were performed. The comparisons between the analytical and experimental re?sults prove the method to be effective. The buffer was designed, manufactured and used in automatic charge pressing system for pyrotechnics. The applied results show that the method can effectively im?prove the charge pressing precision.

Research on Shock Initiation of the High Energy Solid Propellants

WU Jun-ying, CHEN Lang, LU Jian-ying,FENG Chang-gen, WANG Yong-jie

2008, 29(11):  1315-1319.  doi:10.3969/j.issn.1000-1093.2008.11.007

Asbtract ( )   PDF (5101KB) ( )  

References | Related Articles | Metrics

In order to investigate the characters of high energy solid propellants initiated by shock waves, the Lagrange analytical experiment equipment was designed. The pressure histories at the dif?ferent Lagrange places in the propellants were measured by a set of manganin gauges. The detonation pressure, the detonation velocity and the initiation distances of the propellants were analyzed. The shock initiation process of the propellant was numerically simulated by the calculated model of La?grange analytical experiments, the material models of elastopiastic fluid dynamics and the reactive rate equation of ignition growth model. According to the experimental results, the parameters of the reac?tive rate equation of ignition growth model for the propellants were calibrated.

Satisfactory Fault-tolerant Control Against Actuator Failures

HAN Xiao-dong, GE Long, WANG Zhi-quan

2008, 29(11):  1320-1324.  doi:10.3969/j.issn.1000-1093.2008.11.008

Asbtract ( )   PDF (4682KB) ( )  

References | Related Articles | Metrics

For a class of linear discrete-time systems with uncertainties which do not satisfy matching conditions, the problem of quadratic D-stability satisfactory fault-tolerant control with H2 performance index and H-infinity constrains against actuator iailures was presented. Based on a more practical and general model of actuator continuous gain iauures, the consistency method of performance indices was set up for fault-tolerant control and the ranges of H2 performance indices which are consistent with H- infinity indices were analyzed in detail. Meanwhile, sufficient conditions for existence of quadratic D- stability satisfactory fault-tolerant controller were developed. Furthermore, the effective constructive controller design method with constrains of consistent indices was provided.

Temporal Dispersion of Laser Pulse through Clouds and Channel Equalization

CHEN Chun-yi, YANG Hua-min, JIANG Hui-lin,TONG Shou-feng, FAN Jing-tao, HAN Cheng

2008, 29(11):  1325-1329.  doi:10.3969/j.issn.1000-1093.2008.11.009

Asbtract ( )   PDF (4986KB) ( )  

References | Related Articles | Metrics

The multi-scatterings caused by cloud particles induce temporal dispersion of laser pulse, which leads to inter-symbol interference (ISI) in the received signal. The channel model with equaliza?tion filter of laser communication link through clouds was proposed; the temporal response of laser pulse for the different optical thicknesses was obtained by Monte Carlo ray tracking (MCRT) method; the bit error rate (BER) model was deduced in consideration of ISI. The relationships between BER and signal-to-noise rate (SNR) were simulated at different optical thicknesses, with and without e- qualization niter. The simulated results show that equalization filter can mitigate the effect of multi?scatterings of cloud channel obviously.

Design of Multi- benchmark Time Source ifi Time Unification System

HUANG Fei, MING De-xiang, QIAO Chun-jie,WANG Yue-ke

2008, 29(11):  1330-1334.  doi:10.3969/j.issn.1000-1093.2008.11.010

Asbtract ( )   PDF (5334KB) ( )  

References | Related Articles | Metrics

To achieving high time synchronization accuracy among user equipments in the test systems of national defense scientific research, the safe and reliable time source is required. The architecture and model was presented firstly, and the influence of benchmark on time source properties was ana?lyzed .laking aim at the reliable problem of a single time benchmark which provides benchmark time signal for time source, a configuration method of redundancy time benchmark was put forward to im?prove the stability and the reliability of time source. On the basis of the method, the double mode time source based on GPS/BD system was designed, and its performance was verified. The verified results show that the time source performances can satisfy the requirement of ITU-G811 criterion and be used as benchmark clock of CDMA Dase station.

Application of Adaptive Stochastic Jump Filter to Missile Guidance

WANG Hong-qiang, FANG Yang-wang, YIN Hong-wu

2008, 29(11):  1335-1340.  doi:10.3969/j.issn.1000-1093.2008.11.011

Asbtract ( )   PDF (5429KB) ( )  

References | Related Articles | Metrics

Taking aim at the influence of target maneuvering on line of sight (LOS) angular rate be?tween missile and target, an adaptive stochastic jump filter was designed by the information measured with the seeker for filtering the LOS angular rate. The filter can satisfy the requirement of nltering for variable maneuvering modes in the case of computational quantity increased less. Simulated results show that the filter can exactly estimate target maneuvering mode and filter the LOS angular rate ef?fectively, and the filtering results satisfy the performance indexes of the missile guided system.

Effect of the Zn-Al Alloy Microstructures on Adiabatic Deformation Character

GUO Chun-huan, SHI Hai-ming

2008, 29(11):  1341-1346.  doi:10.3969/j.issn.1000-1093.2008.11.012

Asbtract ( )   PDF (5525KB) ( )  

References | Related Articles | Metrics

Adiabatic deformation character of the Zn-Al alloys at higher loading rate was investigated. The thermal viscoplastic constitutive eauation was established by the impact compression and the im?pact shearing tests by the split Hopkinson pressure bar (SHPB), the process of local plastic instability at higher strain rates was analyzed, the criterion of plastic instability was obtained, and the nature of the high strain rate sensitivity for local plastic instability was revealed. It is suggested that the local plastic instability of Zn-Al alloys composed of face-centered CUDIC (FCC) phase a and hexagonal close- packed (HCP) phase η is sensitive to strain rate in plastic deformation; the more the η-phase fraction in microstructures exists, the more intensively the effect of the incoordination in plastic deformation shows and the higher the strain rate sensitivity of local instability is.

Research on Strain Rate Effects of AZ31B Magnesium Alloy of Different Orientation Samples

YANG Yong-biao, WANG Fu-chi, TAN Cheng-wen,WU Yuan-yuan, CAI Hong-nian

2008, 29(11):  1347-1351.  doi:10.3969/j.issn.1000-1093.2008.11.013

Asbtract ( )   PDF (6667KB) ( )  

References | Related Articles | Metrics

Dynamic mechanical properties of the samples with compression axis 90°，45° or 0° from the normal direction of the AZ31B plate were tested using split riopkinsoh bar. The microstructure evolu?tions were analyzed using optical microscope and transmission electron microscope. The analyzed re?sults indicate that the twinned area fraction increases gradually with the increment of the strain, the twinning is main deformation mechanism, its stress-strain curve is concave, for the sample with 90° angle between compression axis and normal direction at a strain rate 1 200 s 一1; the main plastic defor?mations are dislocation and slip, their stress-strain curves are approximate line and convex respectively, for the samples with the angles of 45°，0° between compression axis and normal direction at a strain rate of 28OO s-1; the curves change from concave to convex for 90°sample at a strain rate of 2 800 s-1，due to rapidly increasing twinned area fraction, which changes the orientations of most grains and makes slipping more easily.

Tribological Behaviour and Mechanism of Zirconia Toughened Mullite Composite Ceramic at Elevated Temperatures

TAN Ye-fa, ZHOU Zhao-xia, YU Ai-bing, CAI Wen-Ii, TAN Hua, WANG Xiao-Iong

2008, 29(11):  1352-1357.  doi:10.3969/j.issn.1000-1093.2008.11.014

Asbtract ( )   PDF (6849KB) ( )  

References | Related Articles | Metrics

In order to apply engineering ceramics to inction parts at high temperature conditions, the tribological behaviour and mechanism of zirconia toughened mullite composite ceramic (ZTM) worn a- gainst Y2O3 stabilized zirconia (TZP) ceramic were investigated. The results show that the wear rate of ZTM decrease with the increase of temperature; negative wear phenomenon results from the for?mation of a transferred layer on the worn surface of ZTM, at the condition of that the temperature is higher than 400 °C，the wear rate of TZP increase with the increase of temperature and a severe wear emerges when temperature is higher than 400 °C . The essence of the transferred layer is the surface diffusion of Zr atoms from TZP to ZTM surface. The wear mechanism of ZTM gradually changes from micro-cracking at 25 °C to adhesive wear at elevated temperatures. The wear mechanism of TZP varies from micro-cutting accompanied by plastic deformation at 25 °C to brittle fracture with the elevation of temperature.

Experimental Techniques and Analysis

Study of Environmental Factors of Crew Reliability of Amphibious Armored Vehicles

CAO Wei-guo, LIU Wei-ping, SUN Wei, LI Sheng-dong

2008, 29(11):  1358-1361.  doi:10.3969/j.issn.1000-1093.2008.11.015

Asbtract ( )   PDF (4719KB) ( )  

References | Related Articles | Metrics

The crew reliability of amphibious armored vehicles is affected by both inner factors and out-er ones, of which the environmental factor is an indispensable component. On the basis of the human behavior patterns, the influences of the environmental factors on crew reliability were analyzed, and verified by investigating the crew for the influences in the form of question-and- answer papers. The analyzed and verified conclusions have guiding significance for training armored forces.

A New Method for Measuring the Rifling Angle of Artillery Pipe Based on Template Matching

FENG Zhong-wei, JIAO Kai-he, XU Chun-guang, ZHU Wen-juan，XIAO Ding-guo

2008, 29(11):  1362-1366.  doi:10.3969/j.issn.1000-1093.2008.11.016

Asbtract ( )   PDF (5740KB) ( )  

References | Related Articles | Metrics

In regard to the measurement of rifling angle of artillery barrel, a new method based on template matching was proposed. The measuring system consists of optical sensor, centering device, drive component and controlling computer. The cross section contour of gun barrel was formed by in?tersecting the ring structure light from laser device with the inner wall of gun barrel, and the contour image was obtained by a CCD camera. The rotation angle between sections was obtained by template matching. The rifling equation is fitted based on the distance and the rotation angle between different sections, and the rifling angles at diverse positions were calculated by the equation. Compared with the method using Radon transform, there is no need of edge-detection and high image quality. The results of theoretical analysis and experimental data show that the method has higher measuring accuracy and repeatability.

Real Time Detection Technique for Calculating Angular Velocity of Spinning Projectile in Exterior Trajectory Based on Two-axis Accelerometer

GUO Ze-rong, WU Ri-heng, LI Shi-yi,LI Hong-qi, ZHENG Peng-chao

2008, 29(11):  1367-1372.  doi:10.3969/j.issn.1000-1093.2008.11.017

Asbtract ( )   PDF (5618KB) ( )  

References | Related Articles | Metrics

Real-time calculating projectile’s angular velocity in the outer trajectory is an important part of trajectory resolver design in the trajectory correction fuze. The basic method of the detection is out?side measure or telemetering by rotation speed sensor, which can’t measure every projectile to supply real time data for DSP. The new method of measuring angular velocity of spinning projectile in exterior trajectory was proposed. It is the principle of the new method that the power spectrum of cross accel?eration sample signal is extracted by two-axis accelerometer, a stries of discrete co-t are obtained by combining FIR filter and FFT. Jine tested results can consist with theoretical analysis and meet the need for projectile-borne fuze resolving angular velocity in real-time.

Research Notes

Model of the Estimation of Fire Intersection Based on Vertical Launch Weapons

GUI Qiu-yang, QIU Zhi-ming

2008, 29(11):  1373-1378.  doi:10.3969/j.issn.1000-1093.2008.11.018

Asbtract ( )   PDF (5522KB) ( )  

References | Related Articles | Metrics

It was studied how to establish firepower dispersion model and estimate fire intersection for the vertical launch weapons. The ballistic simulation model of vertical launch missile was established by using quaternion method, and the effect on the ballistic distribution caused by different reasons was an?alyzed through the model. The influence of initial disturbance was discussed and the function, which describes the change of the radius of the distribution along with the time, was given. The model of the distribution of the missiles with the ideal ballistic as the axes and concerned time as one of the control element was built, and the method to solve it was presented. The model can describe the distribution of weapons exactly and estimate the appearance of the firepower intersection.

Research on Optimization Generation Technology for Multiple Fault Diagnostic Strategy

YANG Peng, QIU Jing, LIU Guan-jun

2008, 29(11):  1379-1383.  doi:10.3969/j.issn.1000-1093.2008.11.019

Asbtract ( )   PDF (5332KB) ( )  

References | Related Articles | Metrics

Fault diagnosis strategy generation is a key problem in design for testability (DFT). A sin?gle fault assumption is usually made for existing testability analyses and diagnostic tools, which is not suitable for a complex system. Taking aim at the above mentioned problem, a optimization generation algorithm of multiple fault isolation strategy was presented. The complete minimal cut-set after exe?cuting each step of test was generated by the Boolean logic operation, and the suboptimal multiple fault isolation strategies were generated by the information heuristic algorithm. A test case was given to ver?ify the presented algorithm. The computation results show that the proposed algorithm can efficiently generate multiple fault diagnostic strategies. Since the tests and faults are generalized, so this algo?rithm can be used in optimization generation for multiple fault diagnostic strategies at system, unit and component level.

A New Fast and Intelligent Electronic Image Stabilization Method

ZENG Xue-lian, SHANG Fei

2008, 29(11):  1384-1388.  doi:10.3969/j.issn.1000-1093.2008.11.020

Asbtract ( )   PDF (5288KB) ( )  

References | Related Articles | Metrics

A fast and intelligent electronic image stabilization method for moving camera devices acquir?ing stabilized video was presented to solve well the problems of camera jitter automatic detection and image compensation. The global motion vectors between successive frames were calculated by an im?proved image-interpolation algorithm and thresholds were set to detect if unwanted vibrations existed. An image compensation algorithm, consisted of camera jitter compensation and local motion compensa?tion, was used to translate and rotate the shaky image to the right place so as to achieve a stabilized video. The feasibility of the method was verified by the image stabilization results of the real video se?quences. The experimental and analyzed results show that the method improves the intelligence of the electronic stabilization system.

Analysis and Application of “J” Series Message Format in TADILs

WANG Shun-man, TAO Ran, XU Kai

2008, 29(11):  1389-1394.  doi:10.3969/j.issn.1000-1093.2008.11.021

Asbtract ( )   PDF (6548KB) ( )  

References | Related Articles | Metrics

Based on the important effects in informationization combat and development status in abroad of tactical digital information link (TADIL), as the typical application, J series message for?mat was analyzed. From message head, message content and message encapsulation points of view, tne typical characters and application of fixed format, VMF, free message package and RTT were ana-lyzed and it is pointed out that the development strategy of TADIL standard plays an important role in its application. TaKing aim at the construction status of TADIL in our country, the construction ideas from the technical and management point of view were offered, to promote our army s technique and level of TADIL and infomationization combat through the latecomer surpassing the old-timers.

Modal Analysis of Missile，s Equivalent Density Finite Element Model

ZHAN Qi, LIU Li

2008, 29(11):  1395-1399.  doi:10.3969/j.issn.1000-1093.2008.11.022

Asbtract ( )   PDF (4695KB) ( )  

References | Related Articles | Metrics

For investigating the structural vibration of slender missile, the simplified analysis model needs to be established to analyze structural dynamics characteristics of slender missile containing many non-structural masses. Considering shortcomings of past methods that non-structural mass was equiva?lent to O-D point element or 3-D solid element, the method of equivalent density was proposed, name?ly, according to equivalence theory of density and stiffness, non-structural mass was distributed to the shell elements, and corresponding material density of shell was modified to ensure mass invariaole.the finite element models were respectively established by the three methods, modal test of missile model was accomplished. The comparisons of modal frequencies between experimental and calculating values show that the model established by equivalent density method is more reasonable and easy to use.

Non-linear Predictive Control in the Process of Missile Erecting

YU Chuan-qing, GUO Xiao-song, MA Chang-lin, ZHANG An

2008, 29(11):  1400-1404.  doi:10.3969/j.issn.1000-1093.2008.11.023

Asbtract ( )   PDF (4898KB) ( )  

References | Related Articles | Metrics

To solve the conflict between the speed and the stability in the process of missile erecting, a design of nonlinear predictive control based on neural network was proposed. The nonlinear single gen?eralized predictive control model of missile erecting process was built based on BP neural network. The algorithm for optimal output of the model was deduced, and the specific steps achieving nonlinear sin?gle generalized predictive control were given. The simulated results by the typical nonlinear mathemat?ical model and the missile model, show that the control design is satisfied.

Study on Pressure Control Strategy of High-altitude Multi-Environmental Parameter Simulation Cabin System

CHANG Hai-juan, PANG Li-ping

2008, 29(11):  1405-1408.  doi:10.3969/j.issn.1000-1093.2008.11.024

Asbtract ( )   PDF (4334KB) ( )  

References | Related Articles | Metrics

The high-altitude multi-environmental parameter (temperature, pressure and humidity) simulation cabin is of far reaching significance for studying the plane environmental control system. It is very difficult for the traditional test approach and control method to realize decoupling control of pressure and other environmental parameters and multi- parameter simulation fast and exactly. For this reason, the testing method in which the environmental cabin pressure is controled only by an air evacu?ation valve and the two degree of freedom PID pressure control strategy based on nonlinear compensa?tion were proposed to control pressure in the cabin fast. The controller can overcome the nonlinear flow character of the air evacuation valve with the nonlinear compensation part and pressure control over?shoot with the two degree of freedom PID structure. The simulation results show that the multi-pa?rameters simulation and decoupling control can be realized and the pressure control precision and re?spond speed can be improved by the new test approach and pressure control strategy, which is also suitable for other occasions of controlling the pressure.