基于分簇理论的信息流优化算法研究

将导弹防御指控网络看作变拓扑结构网络,引入小世界网络中"簇"的概念,以最短作战响应时间为优化指标,提出了一种基于平均连接度自适应分簇算法的信息流优化算法。仿真结果表明,该算法在保证信息优裕度的前提下,提高了信息可达度和信息交互质量,提高了指控网络遭受打击时的重构能力。     

压力喷嘴常温下雾化特性实验研究

为了满足工程中对喷嘴雾化特性测量的高精度、低成本要求,建立了喷嘴雾化特性实验系统,以自来水为雾化工质,对蒸发冷却压力喷嘴在常温、常压下的雾化特性进行了实验研究。用容积法测量了喷嘴的流量,用最小二乘法对测量数据进行回归分析,得到了喷嘴流量、雾化压力和喷孔直径之间的关联式与流量系数;用机器视觉方法测量了喷嘴的雾化锥角与雾滴尺寸,得到了雾化锥角与雾滴尺寸随雾化压力变化的规律。结果表明:随着雾化压力的增大,喷嘴雾化锥角不断增加,雾滴尺寸不断减小;随轴向距离的增大,D0.632、D0.5、D32有不同幅度的增大,而D0.9则基本不变。     

基于1.5维谱的船舶轴频电场信号实时检测

为有效地从海洋环境电场中检测出船舶轴频电场信号,在采用正态概率图法分析海洋环境电场高斯性的基础上,利用1.5维谱在抑制高斯噪声和加强谐波信号基频分量等方面的优势,提取特征频段(1～7Hz)范围内的1.5维谱的平均值为特征值,利用滑动检测方法对信号进行了实时检测,并通过实测数据对该检测算法进行验证。结果表明:该方法在信噪比较高和较低的情况下均能较好地实时检测到目标信号,并且在没有目标信号的情况下不会出现虚警。     

舰船水下静态电场深度换算的格林函数法

为从有限深度、有限范围内的舰船水下静态电场数据获知实际舰船更大深度上的场分布特征,在对深海环境中舰船静态电场满足的拉普拉斯方程进行求解的基础上,提出静态电场深度换算的格林函数法,推导出了换算公式的边界积分表达式,给出了实际应用中换算公式的近似计算方法。以舰船静态电场的基本模拟体——单个水平电偶极子的场为例,采用数值仿真的方法对换算公式进行了验证,并对近似计算方法进行了讨论。研究结果表明:该方法可直接通过对测量平面上离散场量进行二重求和来实现静态电场的各类深度换算;与文献中已有的换算方法相比,其换算过程更为快捷。     

激光推力器液体工质注入系统设计

工质注入系统是液体推进剂激光推力器必不可少的一个组成部分。设计并加工了一套脉冲式液态工质注入系统,解决了工质注入和激光脉冲输出同步的问题;并实现了用相位多普勒粒子分析仪对脉冲式雾化液滴性能参数的测试。     

一种改进的遥感图像分形维数提取算法

基于离散分形布朗随机场的图像分数维提取方法,在综合分析和实验验证的基础上,提出了一种改进的图像分形维数计算方法。仿真实验证明,该算法相较于原算法计算结果稳定,不同地物的区分能力强,能够应用于遥感图像的地物分类。     

坦克传动装置润滑系统传动油的流动仿真研究

应用一维流体仿真软件FLOWMASTER2,对坦克传动装置润滑系统的流动进行了模拟,提出了基于FLOWMASTER2软件的传动装置润滑系统的稳态流动仿真模型,并对某型坦克液力机械传动装置润滑系统的流动进行了仿真,预测了润滑系统的流量、流速和压力分布。该研究为坦克及其它车用传动装置润滑系统的流动性能提供了一种有效的理论分析手段和仿真方法。     

Electronic warfare in the optical band: Main features,examples and selected measurement data

The paper presents the possibilities of, and methods for, acquiring, analysing and processing optical signals in order to recognise, identify and counteract threats on the contemporary battleground. The main ways electronic warfare is waged in the optical band of the electromagnetic wave spectrum have been formulated, including the acquisition of optical emitter signatures, as well as ultraviolet (UV) and thermal (IR) signatures. The physical parameters and values describing the emission of laser radiation are discussed, including their importance in terms of creating optical signatures. Moreover, it has been shown that in the transformation of optical signals into signatures, only their spectral and temporal parameters can be applied. This was confirmed in experimental part of the paper, which includes our own measurements of spectral and temporal emission characteristics for three types of binocular laser rangefinders. It has been further shown that through simple registration and quick analysis involving comparison of emission time parameters in the case of UV signatures in “solar-blind” band, various events can be identified quickly and faultlessly. The same is true for IR signatures, where the amplitudes of the recorded signal for several wavelengths are compared. This was confirmed experimentally for UV signatures by registering and then analyzing signals from several events during military exercises at a training ground, namely Rocket Propelled Grenade (RPG) launches and explosions after hitting targets, trinitrotoluene (TNT) explosions, firing armour-piercing, fin-stabilised, discarding sabots (APFSDS) or high explosive (HE) projectiles. The final section describes a proposed model database of emitters, created as a result of analysing and transforming the recorded signals into optical signatures.     

Adaptive phasefield modelling of crack propagation in orthotropic functionally graded materials

In this work, we extend the recently proposed adaptive phase field method to model fracture in orthotropic functionally graded materials (FGMs). A recovery type error indicator combined with quadtree decomposition is employed for adaptive mesh refinement. The proposed approach is capable of capturing the fracture process with a localized mesh refinement that provides notable gains in computational efficiency. The implementation is validated against experimental data and other nu-merical experiments on orthotropic materials with different material orientations. The results reveal an increase in the stiffness and the maximum force with increasing material orientation angle. The study is then extended to the analysis of orthotropic FGMs. It is observed that, if the gradation in fracture properties is neglected, the material gradient plays a secondary role, with the fracture behaviour being dominated by the orthotropy of the material. However, when the toughness increases along the crack propagation path, a substantial gain in fracture resistance is observed.     

垂直刚性面边界条件下水下爆炸气泡运动的理论研究

为研究垂直边界面对水下爆炸气泡脉动的影响,根据势流理论建立了垂直边界面条件下水下爆炸气泡运动的理论模型,编制计算程序进行求解。对水下爆炸气泡脉动运动的特点、流场的速度及压力的分布、气泡引起的载荷形式进行了分析,结果表明,此模型能够反映水下爆炸气泡和周围流体介质的运动规律,并能进行定量的计算。