Table of Content

31 October 2016, Volume 37 Issue 10

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Paper

Backstepping Controller Design for Nonlinear Active Vehicle Suspension Based on Model Reference Control

PANG Hui, CHEN Jia-nan, LIANG Jun, CHEN Ying

2016, 37(10):  1761-1769.  doi:10.3969/j.issn.1000-1093.2016.10.001

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The parameter uncertainties of vehicle suspension system are studied, and a novel backstepping controller design method based on model reference control (MRC) is proposed for nonlinear active vehicle suspension A nonlinear dynamics model of the suspension system is established, and high-pass and low-pass filters are introduced. The pass bandwidths of the high-pass and low-pass filters are changed according to suspension dynamic deflection. An ideal MRC system is designed. On this basis, both the tracking errors of vehicle body displacement and vertical velocity are constructed for the controlled suspension system and MRC system, and a backstepping controller of tracking error is proposed based on backstepping technique and Lyapunov stability theory. The effectiveness and tracking accuracy of the proposed approach are verified through numerical simulation.

Study of Scheme Characteristics of 4-DOF Planetary Gear Transmission Mechanism

LI Shen-long, MAO Ming, GAI Jiang-tao, LIU Shu-cheng

2016, 37(10):  1770-1777.  doi:10.3969/j.issn.1000-1093.2016.10.002

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In order to solve a huge amount of complex optimization calculation of 4-DOF planetary gear mechanism schemes, the scheme characteristics of four-degrees-of-freedom planetary gear transmission mechanism are studied. According to the kinematic relationship among the components of four degrees-of-freedom planetary gear transmission, a mathematical model is established for the coefficients of braking component, clutch and auxiliary component, the gear ratios, the characteristic parameter of planetary gear row, the relative speed of planetary gear, the control torque and efficiency in scheme model. For all possible scheme models with same mechanism, the internal rules of the performance indexes are analyzed to provide a theoretical basis for model classification. A method of component group model classification based on the same control logic principle is put forward. The same kind of component group models can be calculated for one time by using the proposed method for choice of feasibe transmission schemes. The calculated results shows that the proposed method can be used to reduce the optimization calculation of planetary transmission schemes, and improve its efficiency.

Effect of High Pressure Fuel Pipe Structure on Performance of Electronic Unit Pump Fuel System

LYU Xiao-chen， LI Guo-xiu， SUN Zuo-yu， GAO Qing-xiu ， WANG Jie， HE Shuang-yi， CUI Sui-xian

2016, 37(10):  1778-1787.  doi:10.3969/j.issn.1000-1093.2016.10.003

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An one-dimensional hydrodynamic simulation model of electronic unit pump fuel system is established using AMESIM software, and the experimental verification is made for the proposed model. The effects of length, inner diameter and roughness high pressure fuel pipe structure on oil supply pressure, injection pressure and fuel injection quantity of electronic unit pump fuel system are analyzed through numerical simulation. The simulated results show that the structural change in high pressure fuel pipe leads to high pressure volume, flow resistance，throttling loss and dissipation of system, which affect the performance of fuel system. Irregular change in system performance would appear if the high pressure fuel pipe is too long or its inner diameter is too small.

Measurement and Numerical Simulation of Transient Electromagnetic Field in Railgun

LIN Qing-hua， LI Bao-ming

2016, 37(10):  1788-1794.  doi:10.3969/j.issn.1000-1093.2016.10.004

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A 3D transient electromagnetic field model is developed to investigate the characteristics of magnetic field in railgun. The proposed model is solved by a time-domain finite element and boundary-element coupling method. The kinematic process of armature in bore and the space-time distributions of current density and magnetic flux density were obtained. Velocity shin effect due to sliding electrical contact between armature and rails during current diffusion is discussed. In the launch experiment, a B-dot probe is used to measure the armature motion and magnetic filed. The characteristics of change in transient magnetic filed during launch are analyzed. 3D transient electromagnetic filed model of railgun is validated by comparison of experimental results with numerical simulation.

Optimization of Muzzle Disturbance of Overhead Weapon Station Based on Kriging Model

DENG Wei, MAO Bao-quan, FENG Shuai, LI Cheng

2016, 37(10):  1795-1802.  doi:10.3969/j.issn.1000-1093.2016.10.005

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Muzzle disturbance is an important factor to affect the firing accuracy of overhead weapon station (OWS). In order to study the approach to inhibite the muzzle disturbance, an OWS rigid-flexible coupling dynamic model is established based on finite element theory, of which accuracy is verified by the firing accuracy test. The synthetic function of muzzle disturbance is defined as optimization objective to construct an optimization design model of OWS muzzle disturbance, and the Kriging sequential optimization method is used to solve the optimization problem. The simulated results show that the finite element model, considering the flexible deformation of parts , is a good approximation of the vibration characteristics of real system, and Kriging sequential optimization method can be applied to solve the optimization problems of OWS muzzle disturbance. The global optimal solutions searched in optimization problems can be used to suppress OWS muzzle disturbance.

Research on Coupled Thermo-mechanical Model During Rotating Band Engraving Process

LI Miao， QIAN Lin-fang， SUN He-yang

2016, 37(10):  1803-1811.  doi:10.3969/j.issn.1000-1093.2016.10.006

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To investigate the mechanism of engraving process and the rule of initial motion of projectile during lauching process, the engraving process of rotating band of large-caliber howitzer is simulated. The gas pressure distribution of propellant in the tapered chamber is taken into consideration to get the interior ballistic equation during engraving process, and the solution of the equation is taken as the boundary condition of coupled thermo-mechanical analysis of engraving process. Meanwhile, the friction between the rotating band and the barrel is modeled using modified Coulomb model in which the temperature at the interface is taken into consideration. Uncoupled internal ballistic engraving process and adiabatic engraving process are calculated to verify the necessity of the coupled analysis. The resistance, projectile velocity, propellant gas pressure and projectile attitude are got by considering the changes in clearance between projectile and barrel, initial velocity and initial projectile attitude. The calculated results show that the clearance between projectile and barrel plays an important role in determining the resistance and projectile velocity, and the initial projectile attitude has a great effect on the projectile attitude in the process of engraving.

Parameter Estimation of Axial Dual-spin System in a Trajectory Correction Projectile with Decoupled Canards

CHENG Jie， WANG Xiao-ming, YU Ji-yan, JIA Fang-xiu

2016, 37(10):  1812-1819.  doi:10.3969/j.issn.1000-1093.2016.10.007

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The concept of dual-spinning becomes a new approach to upgrade a conventional spin-stabilized projectile, wherein an actuator is used to control the phase of forward canards. To design and analyze the inner control channel efficiently, a dual-spin ordinary differential equation, including a quasi-steady aerodynamic model and an optimized LuGre friction model, is established. All aerodynamic and kinematic data in time-domain, as input in least square estimation, is obtained in transient numerical model and dynamic wind tunnel test. The results indicate that the side force and roll moment supplied by canards are affected by phase angle and roll rate, and the estimated accuracy of quasi-steady aerodynamics is lower than 4×10^-3. The friction between forward and aft parts is a function of axial pressure and relative roll rate, which can be estimated by the optimized LuGre model. The feasibility of using the dual-spin model to predict the canard movement is validated by measurement in a flight test. The proposed approach promotes the pace of engineering application of dual-spin projectiles.

Research on Modeling and Simulation of Echo Signal of Pulse Doppler Fuze and Judgment Criterion of Its Impact

XIAO Ze-long， ZHANG Heng， DONG Hao， NI Bi-xue， XU Jian-zhong

2016, 37(10):  1820-1827.  doi:10.3969/j.issn.1000-1093.2016.10.008

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The existing two-dimensional missile-target encounter model is difficult to simulate accurately the echo signal of fuze for attack. In order to accurately give a judgment criterion for “impact priority” of pulse Doppler fuze, a three-dimensional missile-target engagement model is used to establish fuze echo model, and the mathematical formula of echo signal is derived. The short-time fractional Fourier transform is used to analyze the impact and proximity bursts in the three-dimensional missile-target engagement model. The judgment criteria for pulse Doppler fuze to adaptively select impact function or proximity function are obtained. Matlab simulation results are usedverify the accuracy of the analytical model and the judgment criterion.

Mesh Size Effect and Its Mechanism Research in Numerical Calculation of Rock Dynamics

WANG Hai-bing， ZHANG Hai-bo， TIAN Zhou， OU Zhuo-cheng， ZHOU Gang

2016, 37(10):  1828-1836.  doi:10.3969/j.issn.1000-1093.2016.10.009

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In rock dynamics calculation, the mesh size has an important influence on the reliability of numerically calculated results. A numerical experimental method is used to research the mesh size effect and its sensitivity mechanism in the numerical simulation of propagation of explosion stress wave in rock. The research results show that a proper mesh size should be specified both by the load characteristics and the property of wave propagation medium. When the number of mesh is up to 16 within one load wavelength, the waveforms and peak values of all calculated physical quantities trend to be stable.The relationships between the values of physical quantities and the different mesh densities are also presented. With the increase in distance from explosive source, the sensitivity of physical quantities to mesh size decreases. This is because high-frequency components attenuate gradually, and the wavelength of load becomes longer with the increase in distance from explosive source. The time step coefficient also has a great influence on computational results. When the time step coefficient equals to 0.05, the stable value of displacement tends to converge.

Wideband Compressed Blind Sensing without Reconstruction Based on Expectation Deviation and Generalized Likelihood RatioTest

JIAO Chuan-hai, LI Yong-cheng, XIE Kai, YANG Yun-fu

2016, 37(10):  1837-1843.  doi:10.3969/j.issn.1000-1093.2016.10.010

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A scheme of cooperative wideband compressed blind sensing without reconstruction based on expectation deviation （ExD）and generalized likelihood ratio test (GLRT) , called ExD-GLRT， is proposed to overcome the disadvantages of the traditional wideband spectrum sensing algorithms. The test statistic is extracted from the numerical characteristics of the compressed samples for local mixed spectrum sensing. The cognitive base station (CBS) categorizes the local detection results into two groups and makes a credibility fusion of soft detection results based on GLRT without reconstruction. A global decision is made in CBS. Theoretical analysis and simulated results show that the proposed method is a blinding sensing method which does not require a priori knowledge of signal or noise variance, and can enhance the spectrum sensing capability with low computational complexity.

Individual Communication Transmitter Identification Based on Dempster-Shafer Evidence Theory

GUO Xiao-tao, WANG Xing, ZHOU Dong-qing

2016, 37(10):  1844-1851.  doi:10.3969/j.issn.1000-1093.2016.10.011

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A novel multi-sensor information fusion identification method is proposed for the low accurate rate of the transmitter individual identification caused by the various jamming signals and sensor error, which can enhance the stability and accurate recognition rate of the transmitter individual identification in the complicated environment. The proposed method integrates the Dempster-Shafer evidence theory and feature extraction to get the utmost out of feature information and decrease the influence of uncertain factors in the signal processing. The features are extracted from the detected signals. The self-adaptive fusion rule based on the decision vector is utilized to fuse the evidences transformed by features. The recognition results can be obtained by judgment rules. The simulation analyses of self-adaptive fusion rule and fusion identification method are performed, respectively. The results show that the self-adaptive fusion rule can achieve a great balance between computational efficiency and accurate identification rate. Compared with other identification methods, the proposed fusion identification method can provide more accurate and stable recognition results.

The Evolution of Gas-liquid Flow of Multiple Combustion Gas Jets in a Cylindrical Water-filled Chamber

ZHAO Jia-jun, YU Yong-gang

2016, 37(10):  1852-1859.  doi:10.3969/j.issn.1000-1093.2016.10.012

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The injection process of multiple high-pressure combustion gas jets is observed experimentally and simulated numerically during gun firing underwater. The gas is generated by gunpowder burning and injected into a cylindrical water-filled chamber through simulated bullet. In experiment, a high-speed camera system is used to record the injecting process of air. The volume-of-fluid method is used to describe the expansion of the gas cavities in water. The numerical results show a good agreement with experimental observations. Numerical simulations show that the gas pressure along the axis of orifice reaches a steady value after declining and rising. A pressure peak appears in the water near the gas cavity under the effect of combustion gas, and then is gradually attenuated. During the expansion of the gas cavities, the pressure distribution of gas-water flow field on a cross section away from nozzle is relatively uniform, and the average pressure on the section decreases with the expansion in the cavity. The area fraction of gas on the section could be up to 70% over time.

Research on Ricochet Process of Small-angle Water-entry Vehicle

LI Yong-li, LIU An, FENG Jin-fu， HU Jun-hua， YU Zong-jin， QI Duo

2016, 37(10):  1860-1872.  doi:10.3969/j.issn.1000-1093.2016.10.013

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In order to study the ricochet phenomenon of trans-media vehicle entering into water at small angle, a numerical model is built based on CFX, and the accuracy and applicability of the model are verified. The ricochet progress of the vehicle with different vertex angles, different densities and variable truncated annular grooves while entering into water at small angle are simulated. The whole ricochet progress and the change rules of angular acceleration, angular velocity and displacement during the progress are analyzed. The research results show that small vertex and density of vehicle would lead to the upward curving of ballistic trajectory, thus the ricochet phenomenon is more likely to occur, and the angular velocity mutation is due to the strike of the tail of vehicle on the water surface in the inundation stage; the truncated annular groove ogive has certain inhibitory effect on the ricochet of vehicle, and the position of the annular groove is very influential to the process of water entry, which can be chosen according to the task demands.

Matching Analysis of Piston Motion Law of Opposed-piston Two-stroke Gasoline Engine

MA Fu-kang, ZHAO Chang-lu, ZHAO Zhen-feng, WANG Hao

2016, 37(10):  1873-1880.  doi:10.3969/j.issn.1000-1093.2016.10.014

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A three-dimensional computational fluid dynamics mode for a scavenging system is established to study the scavenging flow in opposed-piston two-stroke (OP2S) gasoline engine. The boundary and initial conditions are obtained from the simulated results of one-dimensional working process. As the opposed-piston relative dynamic characteristics of OP2S gasoline engine depend on different design and operating parameters, such as phase difference of opposed-piston motion and crank radius-connecting rod length ratio, a numerical simulation program is built using MATLAB/Simulink to define the opposed-piston motion profiles based on equivalent crank angle of opposed crank-connecting rod mechanism. The phase difference of opposed-piston motion only affects scavenging timing while crank radius-connecting rod length ratio affects scavenging timing and duration. Scavenging timing and duration are main factors which affect scavenging performance. The analysis results indicate that the optimal matching of phase difference of opposed piston motion and crank radius-connecting rod length ratio has the potential to achieve high scavenging and trapping efficiencies with a right flow in cylinder. Around the inner dead center, the phase difference of opposed-piston motion affects the relative velocity of opposed piston and minimum working volume, and the crank radius-connecting rod length ratio only affects the relative velocity of opposed-piston.

Optimization of Operational Mission-oriented Carried Spares Allocation of Armored Equipment

WANG Tie-ning, LI Hao, WANG Sheng-feng, HAN Chao-shuai

2016, 37(10):  1881-1888.  doi:10.3969/j.issn.1000-1093.2016.10.015

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An optimization model of operational mission-oriented carried spare parts allocation for armored equipment is established to improve the pertinence of carried spare parts allocation scheme. In the proposed model, the armored equipment that perform the multi-stage operational mission are taken as the study object, the effects of operational mission, equipment and preset spare parts depot on urgent repair strategy are taken into comprehensive consideration, which plans as a whole of the accompanying maintenance support capacity and spare parts demand. The feasibility and effectiveness of the proposed model are demonstrated through an example.

Variable Value Control Technology of Genetic Algorithm for WTA of Ground Target Attacking

WANG Ran-hui， WANG Chao

2016, 37(10):  1889-1895.  doi:10.3969/j.issn.1000-1093.2016.10.016

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Research on weapon-target assignment (WTA) of ground target attacking is very difficult due to a wide variety of targets and weapons. A reasonable WTA scheme is developed to optimize the allocation of limited resources, which brings the maximum battlefield gains with minimum costs. For this reason, a mathematical model is established, and the genetic algorithm is used to resolve the optimal result of weapon-target assignment. But the convergence rate of genetic algorithm is slow and can't even give a feasible solution in solving WTA. A state variable control method is designed to overcome the insufficient of the genetic algorithm. The proposed method can reduce the search space and improve the search efficiency by restraining and controlling the value range of the initial population variables, and ensure the quality of the solution by improving the mutation strategy to expand the value range of the variables. The simulated result shows that the improved genetic algorithm can solve the WTA problem of attacking the ground targets on a large scale effectively.

Detection and Identification of Axial and Radial Impacts on Pneumatic Muscle

WANG Bin-rui, REN Jie, XU Hai-dong, BAO Chun-lei

2016, 37(10):  1896-1901.  doi:10.3969/j.issn.1000-1093.2016.10.017

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Impact detection is a challenge in research of bionic driver. Axial and radial impact characteristics of pneumatic muscle are analyzed based on the tube cavity effect, and the differential pressure signal is modeled using the fluid impedance method. An impact test platform is established and used to gain the effects of load, pressure, impact intensity and radial impact position on the differential pressure signal. The periodic changes in the phase frequency curves of differential pressure signal under axial and radial impacts are compared. Autocorrelation function method is used to extract the periodic characteristics of the differential pressure signal. Forty groups of validation experiments are implemented. The experimental results show that the axial and radial impacts can be detected and identified by the autocorrelation function method of differential pressure signal. The identification accuracy is 97.5%.

Comprehensive Review

An Overview of Developmentand Research on Bottom Protection Capability of Military Vehicle

SHI Bing-liang， WANG Xian-hui， ZHANG Yun， HE Jian-qing

2016, 37(10):  1902-1914.  doi:10.3969/j.issn.1000-1093.2016.10.018

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Bottom protection，which is of great significance for improving the survivability of military vehicles and providing effective protection for crew，has become one of the research hotspots of the military vehicles. The research on bottom protection technique of military vehicles, the analysis of protection capability and optimization of structure based on numerical simulation, the evaluation of bottom protection capability, the bottom protection strategies and their applications, the technical measures and protection capability of typical vehicles are reviewed. The technical measures which include V-shape bottom hull, tabulate bottom floor made of new type material, interior structure of vehicle and crew restraint systems are expatiated. The application and research status of numerical simulation technology which is used to analyze the protection capability of military vehicle and optimize the bottom structure of vehicle are discussed. The research status of the effects of explosion shock on vehicle and its crew and the test evaluation of the bottom protection abilities of vehicle are analyzed. Simple local protection, locally added protection kits, special protection body with protection kits, and integrated protection solution are summed up. The bottom protection measures and capability of typical vehicles are analyzed. In addition，the future research direction and priorities of bottom protection , and how to develop the protection capability of military vehicles are suggested.

Research Notes

Research on the Starting Response of Heavy-duty Off-road Vehicle on Plateau

HUANG Mian-dun, ZHANG Fu-jun, CUI Tao, LIU Xue-yuan

2016, 37(10):  1915-1925.  doi:10.3969/j.issn.1000-1093.2016.10.019

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To study the starting response of heavy-duty off-road vehicle on plateau, a full vehicle model is established using GT-SUITE. The effects of altitude, gear shifting moment of and front gear ratio on the starting-up process of heavy-duty off-road vehicle are studied through simulation. The research results show that the starting process of vehicle takes 14.7 s on plain, while it takes 27.2 s at the altitude of 4 500 m; in comparison with the gear shifting at 1 000 r/min, the response time of starting is decreased by 3.9 s at 2 000 r/min. Therefore, the vehicle starting response can be improved by shifting gear at high engine speed. With the increase in front gear ratio, acceleration increases during starting, but the vehicle speed decreases at steady state. Therefore, the starting response of vehicle can be improved by choosing an apposite front gear ratio. Due to the influence of air-fuel ratio limit, the common input characteristics of hydraulic torque converter and engine during starting are different from the common input characteristics of hydraulic torque converter corresponding to engine full load characteristics at the altitude of 4 500 m.

Barrel Life Prediction of Rotating Barrels Machine Gun Based on Fatigue Damage of Chromium-steel Interface

XU Ning, WU Yong-hai, WANG Yong-juan, XU Cheng

2016, 37(10):  1926-1933.  doi:10.3969/j.issn.1000-1093.2016.10.020

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To predict the life of a gun barrel, the theories of thermal-solid coupled stress, the impact fatigue and fatigue cumulative damage are used to derive the life prediction of a gun barrel based on fatigue damage of chromium-steel interface. A 3D finite element model for a 3-barrels rotating machine gun is built to calculate the coupling stress of chromium-steel interface. The barrel life of the rotating barrels machine gun is estimated. The estimated result is basically consistent with the experimental result. The analysis results show that the fatigue damage life at chromium-steel interface almost determines the life of the gun barrel. The effect of the thickness of chromium coating on the life of gun barrel is studied. The research result shows that the life of gun barrel can be improved by increasing the thickness of chromium coating properly.

Design Scheme Evaluation Based on Fuzzy Decision Maps and Grey Relational Analysis

YAN Yan， HAO Jia ， CHEN Zhong-ming， WANG Guo-xin， SHA Jin-long

2016, 37(10):  1934-1940.  doi:10.3969/j.issn.1000-1093.2016.10.021

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A scheme evaluation method based on fuzzy decision maps and grey relational analysis is proposed to solve the problem of mutual influence of the design scheme evaluation indexes. The proposed method takes grey relational analysis as a main evaluation progress, and uses fuzzy cognitive map to represent the mutual influence of the evaluation indexes. The fuzzy decision maps are used to calculate the influence relationship among the evaluation indexes. The grey relational grades of all alternatives are calculated to determine the optimal scheme. The feasibility of the proposed method is verified by taking the design scheme evaluation of small arms for example.

Establishment and Simulation of Two-dimensional Interior Ballistics Model of Large Caliber Davis Gun Considering the Axial Movement of Tubular Charge Clusters

JIANG Shu-yuan, WANG Hao, LIN Chang-jin, WANG Jin-long

2016, 37(10):  1941-1948.  doi:10.3969/j.issn.1000-1093.2016.10.022

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Considering that the length of the tubular charge for the large caliber high speed Davis gun is long, the traditional pseudo-fluid hypothesis in two-phase flow model may cause errors. In order to solve this problem, Eulerian coordinate system is used to settle the gas field, and the Lagrangian coordinate system is used to settle the solid field. It is assumed that the tubular charge clusters are linearly configured along radial direction, these clusters move along axial direction，and gas moves along radial and axial directions. Based on this assumption, a two-dimensional interior ballistics model is established for a 480 mm Davis gun with tubular modular charge. Then through the comparison of the simulated and experimental results, the proposed model is verified to be effective. The distribution of gas pressure along two directions and the movement rules of tubular charge clusters along axial direction were obtained by further analysis of the simulated results.

Simulation for Launch Process of Ultrahigh Firing Rate Guns Based on Two-way Coupling of FLUENT and Interior BallisticModel

LUO Qiao, ZHANG Xiao-bing

2016, 37(10):  1949-1955.  doi:10.3969/j.issn.1000-1093.2016.10.023

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The numerical simulation accuracy of interior ballistics of ultrahigh firing rate guns depends on the accuracy of calculating the drag force acting on projectile nose. In order to improve the numerical simulation accuracy of interior ballistics of ultrahigh firing rate gun, the secondary development tool UDF is used to couple FLUENT and the classic interior ballistic (CIB) model for the calculation of flow field in front of projectile. The nose drag force of the second launched projectile is obtained, and the variation law of nose drag force at different firing rates is analyzed. The simulated results show that the propellant gas flow field distribution can be obtained by the two-way coupling of FLUENT and CIB model, and the accuracy of calculating the nose drag force is improved. The nose drag force increases quickly after launching, and then decreases after it reaches a maximum value until the projectile leaves the muzzle. This variation law is common at different firing rates. When the firing rate reduces, the increased amplitude of nose drag force decreases at the earlier stage of projectile movement, and its decreased amplitude also decreases at the later stage of projectile movement.

Error Separation and Surface Topography Prediction of Shaft and Hole Based on Harmonic Theory

SU Chang-qing， SUN Ye-xiang， QU Li-gang， YE Bai-chao， YANG Ye-guang

2016, 37(10):  1956-1963.  doi:10.3969/j.issn.1000-1093.2016.10.024

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As one of the most widely used core parts in mechanical products, the shaft and hole parts tend to develop towards high precision, high strength and diversity. The quality control and quality evaluation are very important for shaft and hole parts. For the shape error separation of the shaft and hole parts, a harmonic separation method is proposed based on the research on the traditional error separation technique and the harmonic theory. According to the periodic data measured on the parts, the generation mechanism of each harmonic error is analyzed, and the measures to reduce the error are put forward. The actual position of the measuring point is obtained by using the space point vector method, and the surface topographies of the parts are predicted by combining with the surface fitting algorithm. The accuracy and rationality of the harmonic separation and surface topography prediction method are verified by experiments. Those methods provide a new idea for the surface quality evaluation and prediction of shaft and hole parts.

Research on Approaches to Processing of Measured Thickness Data of Transparent Material Based on Polychromatic ConfocalTechnology

AN Zhe, XU Xi-ping, QIAO Yang, ZHANG Ning, LYU Yao-wen

2016, 37(10):  1964-1968.  doi:10.3969/j.issn.1000-1093.2016.10.025

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In order to meet the requirement of measuring thickness of transparent materials for precision optical lens and glass container, etc., the polychromatic confocal method is used to measure the thickness of transparent material. The measuring principle of confocal system is introduced. A measuring structure scheme is proposed, and an experimental device is constructed and calibrated. The linear regression method is adopted to process the experimental data. The proposed method is to use linear prediction function to construct a mathematical model. The parameters in the model are determined using the measured data. The thickness model is improved by compensating error. The experimental results show that the measuring range of confocal system can reach 15 mm, and the accuracy of measurement is ±3 μm. The compound color confocal method is a kind of online non-contact measurement technique with high precision.