Numerical analysis of interior ballistics through eulerian-lagrangian approach

A numerical code for interior ballistics using the Eulerian-Lagrangian approach was developed to analyze polydisperse systems. The internal flows in a gun barrel and the compressibility effects were calculated using the semi-implicit method for pressure-linked equations algorithm. Ghost cell extrapolation was used for the moving boundary with projectile movement. The numerical scheme and moving boundary method were verified through the free piston motion problem. The developed code, including the combustion of the propellant, was compared with simulations of 40 mm gun firings. The results of numerical analysis agree with the simulation results, confirming the reliability of the developed code. Comparative studies were conducted with the results of the interior Ballistics of high-velocity guns code (version 2) according to porosity and propellant size. The numerical analysis of the combustion and movement of individual propellants provides deeper insight into the mechanism of gun firing and the significant factors that influence muzzle velocity.     

浅谈火炮身管加工工艺

身管是火炮武器的重要部件,身管制造材料和加工工艺直接影响身管的质量。身管质量严重影响身管寿命,低质身管会导致火炮内弹道性能降低,射击精度下降,制约着武器效能的发挥。深入研究身管问题,分析了身管使用材料发展历程,归纳总结出身管的典型加工工艺,为身管的设计和使用提供参考。     

火炮身管精密加工与在线检测技术研究

火炮身管是火炮的关键零部件,由于其长径比大、要求精度高,它的加工属于深孔精密加工范畴,而国内对此加工的生产水平落后,加工效率低、质量差。火炮身管药室高效精密数控镗床的设计制造满足药室加工多锥段、高精度要求,加工效率较传统工艺提高数倍。该设备能够实现多品种、小批量、高精度加工生产的需求。火炮身管缠度检测原理样机由炮膛爬行器、缠度测头和计算机控制与数据处理系统3部分构成,经检测可实现较低的测量误差。     

Development of three-dimensional numerical model for combustion-flow in interior ballistics

Interior ballistics analysis is required for the development of the gun system. Interior ballistics is a complex phenomenon containing the propellant combustion and gas flow and is completed in tens of milliseconds during gun firing. Thus, some data cannot be directly measured by experiment. Numerical analysis is therefore traditionally used to understand the complex gun firing phenomena. In previous studies, the two-dimensional axisymmetric numerical method for interior ballistics using the Eulerian-Lagrangian approach has been developed. There are some limits in depicting the actual phenomena with two-dimensional models. Therefore, a three-dimensional numerical model has been built in the present study. Unlike the conventional method, the calculation has been conducted by separating the physical phenomena into the combustion part and the flow part for simplicity and efficiency. The internal flow in the gun barrel has been calculated by using the STAR-CCM+ and the source terms produced by the propellant combustion has been computed by utilizing the existing code. The developed numerical model has been compared with the AGARD gun results and the simulation of 40 mm gun firings. The reliability of the developed model has been confirmed because the results of the numerical analysis greatly agree with the simulation results. The basis of the three-dimensional analysis of the interior ballistics has been formed through this study.     

Numerical and experimental studies on the dynamic behaviors of a gun that uses the soft recoil system

The conventional recoil mechanism of guns provides the retarding force on the gun to stop the rearward motion in the firing cycle. The concept of the soft recoil mechanism has been developed. This mechanism was introduced to reduce the firing shock and the reaction force due to the forward momentum of the recoiling parts prior to firing. This paper verifies the theory of the soft recoil mechanism and demonstrates its feasibility on a large-caliber gun system. Numerical simulation on recoil dynamics and shock response analysis were utilized in this study. A FORTRAN program, which was developed in a previous study, was employed for simulation. The shock response analysis utilized the shock response spectrum and the pseudo-velocity shock spectrum. As a result, a newly developed recoil system was proven to be applicable for guns in the near future with further refinements.     

火炮身管寿命研究

身管是火炮自动武器的重要部件,身管损伤严重影响身管寿命,导致火炮内弹道性能降低,射击精度下降,制约着武器效能的发挥。深入研究身管寿命问题,分析了影响身管寿命的各种因素,归纳总结出身管延寿的主要措施,为身管的设计和使用提供参考。     

弹性胶泥冲击加载缓冲器设计

在进行火炮后坐运动动态模拟实验时,为了使被试火炮产生与实弹射击相同的后坐动态响应,需要对冲击加载载荷进行控制。通常可在冲量发生器和后坐部分之间加装缓冲器,利用缓冲器的刚度特性,控制传递到后坐部分的载荷,以实现与火药燃气形成的炮膛合力相同的变化规律。根据火炮后坐动态模拟实验的需求,应用新型弹性胶泥材料,设计了用于冲击载荷控制的加载缓冲器。利用被试火炮后坐运动的数学模型,在MATLAB/Simulink中建立了后坐动态模拟试验的仿真模型,对后坐运动及缓冲器参数进行了仿真计算。仿真结果表明,弹性胶泥缓冲器可以较好地实现火炮发射的炮膛合力,满足火炮后坐动态模拟实验的要求。     

某超高射速武器身管设计方法

超高射速武器是一种新概念武器,其显著特点是射速高。身管是其关键部件,直接制约着武器效能的发挥。为了设计合理可用的身管,首先使用matlab软件进行数值模拟,得出了在给定条件下身管的受力情况。再对各种强度理论进行分析,在此基础上,采用平均压力法来设计身管。给出了某超高射速武器身管结构尺寸的设计结果。该技术研究可为超高射速武器结构设计提供一定理论参考。     

空间光学载荷探测器组件抗冲击隔振设计

针对广角极光成像仪整机Z向冲击试验后探测器损坏的问题,提出在镜头组件与头部框架间设置隔振器的解决方法。首先,确定隔振方案为被动局部隔振;然后,从材料、刚度和安装方式等方面完成金属橡胶隔振器的设计。接着,运用有限元方法对结构进行模态分析和冲击载荷响应仿真分析。最后,对广角极光成像仪整机产品进行了力学实验,实验结果与仿真分析结果一致。实验结果显示:安装隔振器后,探测器位置测点的正弦振动加速度响应最大降低了26.2%,随机振动加速度响应最大降低了72%,冲击加速度响应最大降低了48%,说明该隔振器具有显著的减振效果。在实验完成后对产品进行检测,发现产品并无异常,说明结构设计满足要求。     

基于电磁作动的冲击振动主动控制技术

针对恶劣的振动冲击环境,提出一种基于电磁作动的冲击振动主动控制技术,并研制了一套电磁执行装置。对实验样机的数值份真和试验结果表明,系统可以兼顾振动与冲击控制,具有无谐振峰和较宽的频率响应范围、较大的位移响应范围和较为理想的隔振率的优点。     

双光谱热成像摄像机在输油管道智能监控的探讨

本文针对现有输油管道监控方式的不足,提出了基于双光谱热成像摄像机和智能分析监控系统,解决传统人工巡线和可见光视频监控无法全面有效监控的缺陷,并对其技术特点和应用进行了分析探讨。     

考虑耳轴间隙的自动炮射击过程动态响应分析

基于多体动力学理论建立了考虑耳轴轴承间隙非线性的某型步兵战车自动炮刚柔耦合发射动力学模型.应用ANSYS有限元分析软件建立了双炮身管结构有限元模型并结合自动炮射击过程中力学特性和约束特性分析建立了自动炮刚柔耦合发射动力学模型;应用有限单元法对耳轴轴承间隙非线性进行了参数辨识,并准确分析了自动炮射击过程中耳轴轴承间隙对炮口扰动的影响,分析结果表明基于有限单元法的间隙非线性参数辨识方法能准确描述含间隙耳轴轴承的接触特性,为分析自动炮射击精度提供了准确的模型基础.     

汽车三级分段变刚度双质量飞轮非线性振动研究

分析了三级分段变刚度双质量飞轮（DMF）刚度随扭转角变化的特征,考虑刚度非线性因素建立了搭载DMF的汽车传动系非线性扭转振动模型和对应的微分方程,采用平均法和Runge-Kutta数值积分方法编制算法程序,推导和分析扭转角非线性频率特性近似解析解,并对不同转矩频率下的强迫振动响应进行仿真分析,以进一步探究三级分段变刚度DMF在传动系统中的非线性振动特性。     

基于AWE对星形截面身管的强度分析

针对防空武器的发展,设计星形身管并对其进行强度校核。考虑到发射过程中身管内壁压力的变化特点,对传统身管和星形身管进行了有限元分析。由于身管可以简化为二维轴对称结构,故将身管内表面分段,分别施加膛压,分析身管强度。     

Microscopic Cracking and Spalling Behavior of the Duplex Layer of a Gas-Nitrided Gun Bore Surface

In the present study, the initial wear behavior of the duplex layer consisting of an oxide film and a compound layer on gun bores was investigated. The duplex layer was produced by the gas-nitriding and the post-oxidization to the surface of the 5.56mm gun bores. The thickness of the duplex layer was measured from the specimen taken from a new gun barrel with an optical microscope. After real firing, the specimens were cut from the barrels. The microscopic wear behavior and phase identification of the duplex layer were observed by using a SEM and a XRD, respectively. A lot of surface cracks linked together to form the network of the cracks on the surface and the parallel cracks occurred in the interface between the oxide film and the compound layer. When the surface cracks and the parallel cracks join orthogonally, the spalling takes place.     

弹丸膛内运动研究

弹丸膛内运动是火炮发射过程的重要组成部分,其显著特点是过程极短,受力复杂。身管与弹丸的相互作用,严重影响火炮射击精度,直接制约着武器效能的发挥。对近年来国内外膛内运动情况进行了深入分析,最后指出关键性的待解决问题与发展方向,可为身管与弹丸设计提供一定理论参考。     

Numerical and experimental analysis of coupled transverse and longitudinal vibration of a marine propulsion shaft

An appropriate assessment of the dynamic behavior of marine propulsion shaft in ships is essential to enable optional delivery of power to the propeller and to minimize unnecessary vibration. Various vibrations coupling with each other can significantly influence the dynamical behavior of the shaft and threaten the reliability of ships. This paper presents a finite element analysis model with multiple constraint conditions to analyze the coupled transverse and longitudinal vibrations of a marine propulsion shaft. Based on this model, in addition to the coupled natural frequencies of each direction, the maximum acceleration are also determined. Furthermore, the simulation of an idling and loading vibration analysis is discussed and validated against experimental results, over a range of rotational speeds. The output of numerical simulation is found to agree with the corresponding results from experimental tests. Finally, an accurate and applicative FEA model for coupled transverse-longitudinal vibration of shaft has been obtained.     

多功能便携式火炮身管内膛擦拭机的设计

介绍了火炮身管内膛擦拭机的结构组成、工作原理与特点。分析了火炮身管内膛擦拭机的设计要点。试验样机的测试结果表明,本文设计的火炮身管内膛擦拭机携带方便、安装简易、操作便捷、自动化程度高、擦拭效果好、适用范围广,达到了预期的设计效果。     

基于知识的枪管CAD系统的研究与开发

知识的表示与数据库的构造是开发基于知识的枪管 CAD系统的关键。本文采用规则与框架混合的方法表达设计知识 ,以面向对象的方法构造数据库 ,并在专家系统工具 CL IPS上加以实现。采用参数化设计的方法使设计结果实现了数据与图形的结合。通过综合运用上述技术开发的基于知识的枪管 CAD系统较好地解决了枪械主要零部件——枪管的自动化设计问题     

薄壁身管强度分析

某型号步兵战车配有100mm低膛压火炮,该炮身管距炮口945mm的范围内为薄壁圆筒.文章以该段薄壁身管为研究对象,将其简化为内压薄壁圆筒,在只考虑切向应力的情况下,通过静力学理论分析和有限元分析(软件ANSYS)对其强度进行了求解和对比,结果证实两种方法虽均切实可行,但相比之下理论公式更为精确.