基于HLA的防区外空面导弹攻防对抗仿真

针对HLA/RTI在接口规范、对象模型模板等关键技术建立分布式仿真平台的复杂性,提出了利用数字武器开发平台进行开发的方法,构建防区外空面导弹攻防对抗系统体系结构,实现了该体系结构联邦成员划分、设计联邦/仿真对象模型表等HLA仿真关键技术,并采用面向对象建模与仿真技术建立了各联邦成员的数学模型.该仿真结果表明,各联邦成员的数学模型与底层支撑环境能够相互分离,仿真模型具有良好的交互性和互操作性,可通过添加或删除联邦成员仿真不同的复杂战场想定,并可作为验证不同算例的仿真平台.     

基于循环平稳的卫星信道多普勒频移估计

基于线性调制信号的循环平稳特性,卫星信道多普勒频移的估计可以通过求解发送信号与接收信号的循环相关函数关系得到.借助循环谱函数推导出发送信号的循环相关函数,接收信号的循环相关函数则对信号本身及其有限差分进行计算.仿真结果说明了该算法对信道中的干扰与噪声不敏感,在多普勒频移较大时,该算法具有良好的估计精度;同时该算法还具有低复杂度和应用灵活的特点.     

战术导弹靶场试验风险分析与处理方法

从战术导弹靶场试验风险因素存在的主要环节分析入手,建立了风险因素指标体系,结合靶场试验特点阐述了风险辨识、评估、处理的原则和方法,结合某型舰空导弹试验靶标保障的工程问题,对该靶标供靶风险进行了辨识,对风险发生的概率和后果严重性作出了评估,并在此基础上提出了解决问题的基本途径.     

稀薄气体动理论中介观尺度数值模拟的加速方法

针对滑移流、早期过渡流区域采用离散速度法(discrete velocity method, DVM)求解Boltzmann方程收敛速度极慢、计算资源消耗大的难题,提出全流场耦合介观/宏观方程加速方法。在介观层面基于有限差分的DVM求解Boltzmann方程,在宏观层面基于有限体积的压力耦合方程组半隐式方法求解矩方程,充分利用纳维-斯托克斯-傅里叶/R26矩方程在低克努森数下的快速收敛特性,对介观方程进行加速。基于高阶Hermite多项式重构分布函数,完成宏观方程与介观方程之间的数据传输。仿真结果表明:全流场耦合介观/宏观方程的加速方法在滑移流、早期过渡流区域具有显著加速性能,最大降低了95.28%的计算时长;但对中、大克努森数流域,加速性能大幅度下降。     

Investigations on influence of rifle automatics system action on values of energetic efficiency coefficient of muzzle brakes

The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems. Special laboratory stand designed for investigating the recoil process was used. The motion of the rifle was detected by the use of the laser interferometer and the optical camera. The recoil velocity time courses were determined by smoothing and differentiation of experimental position records. The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient: the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle. The values of the coefficient, calculated using these two values of the recoil velocity, distinctly differ. However, it was shown that their values indicate the same relation between the efficiency of various muzzle brakes. The value of the efficiency coefficient, determined on the basis of the final recoil velocity value, is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system.     

Investigation of the shock compression behaviors of Al/PTFE composites with experimental and a 3D mesoscale-model

The responses of AI/PTFE reactive materials (RMs) under shock compression were investigated by a single-stage gas gun.A 3D mesoscale-model was established based on micro-computed tomography(micro-CT) slice images and confirmed with experimental results.In the high-pressure stage,the com-posites reacted partially,whereas there were no deviations between the partially reacted Hugoniot and the inert simulation results.The simulation reveals that the Teflon matrix melting on the high shock pressure.Melts and decomposition of the PTFE accelerated the diffusion of the atoms.Thus,the reactions of the Al/PrFE composites are more like a combustion rather than a detonation.     

On the Road to the 2015 NPT Review Conference

The second session of the Preparatory Committee for the 2015 Review Conference (RevCon) of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) highlighted two issues in particular—progress toward a Middle East Weapons of Mass Destruction–Free Zone and the Joint Statement on the humanitarian impact of nuclear weapons—that may not only greatly affect the health and vitality of the NPT and the 2015 RevCon, but possibly also have implications for the international nonproliferation regime as a whole. Dr. William Potter, director of the James Martin Center for Nonproliferation Studies, interviewed Ambassador Cornel Feruta, chairman of the 2013 PrepCom, to discuss these and other issues related to the meeting and the future of the treaty and its review process.     

Investigating the Desirability of Navy Aircraft Service Life Extension Programs

Building on prior work on optimal replacement of aging aircraft, this paper presents three methodologies to evaluate prospective aviation Service Life Extension Programs (SLEPs) and applies these methodologies to US Navy F/A-18E/F data. While considerable uncertainty remains as to the values of key parameters (e.g. the cost of F/A-18E/F SLEPs), the preponderance of the evidence available at this juncture favors undertaking SLEPs on F/A-18E/Fs rather than replacing them with new Joint Strike Fighters.     

弹道修正弹射程偏差预测与阻力板展开时机优化

根据弹道修正弹阻力板的展开控制对于射程偏差预测要求的实时性,提出基于摄动原理的射程偏差预测算法.为解决阻力板修正能力在线计算数据量大的问题,提出在弹载计算机上装定阻力板修正能力表格的方法,给出发射前计算修正能力表格的过程和飞行中使用修正能力表格的步骤,提出阻力板展开时机的优化判断条件,并采用该方法对某型弹道修正火箭弹射程修正控制进行仿真试验和飞行试验.仿真试验结果表明,当目标射程为33 565.4m时,经修正后火箭弹的射程偏差能控制在20m以内;飞行试验结果表明,弹道修正火箭弹的射程偏差实测为24m,射程精度得到明显提高.     

基于FEM/SPH算法的弹丸侵彻土体数值模拟

基于有限元法(FEM)和光滑粒子流体动力学(SPH)结合的算法,用数值模拟了钢质弹丸对钢筒约束土体的侵彻过程。基于ANSYS/LS-DYNA显式动力分析和LS-PrePost后处理软件,形象再现了钢质弹丸冲击作用下土体飞溅形成漏斗坑和直线通道的物理过程。侵彻深度计算结果与实验数据吻合较好,钢质弹丸的速度和加速度时程曲线图与理论分析一致,体现了FEM/SPH算法的精确性。研究结果表明FEM/SPH算法在模拟侵彻土体方面具有可行性和有效性。