航空电子综合系统作战飞行程序的研究

本文研究了作战飞行程序的开发及开发环境的基本原理,并对开发环境的基本软件组成、硬件结构及其应用进行了讨论。     

新型扫雷装药爆炸场特性分析及应用

基于爆破法扫雷爆破筒扫雷作用原理,设计了8.2 kg一次引爆型固态FAE扫雷装置。通过改变起爆位置和设置方式,多次野外近地面爆炸试验,采用反射压力传感器在装药正向与侧向离爆点不同位置进行压力测试,同时在正向测线压力传感器的对应位置设置某型防步兵地雷,得到爆炸场不同位置处的爆炸参数以及防步兵雷扫雷范围。结果表明:水平设置扫雷装药的扫雷范围明显大于垂直设置的装药,最佳炸高约为0.60 m;且其爆炸场正压区作用时间曲线呈“V”形,产物作用范围达63倍装药半径,与等当量的TNT的作用时间有明显的优势;本装置的扫雷范围约为目前扫雷爆破筒爆破扫雷范围的1.8～3.85倍,正向可靠扫雷范围可达其装药半径的77倍,侧向达69倍。由于该装药爆炸作用区域正压作用时间明显加长,因此有利于各种地雷的清除,是一种潜在高效的爆破法扫雷装药。     

激光辐照下45#钢板响应特性

采取实验和数值模拟相结合的方法对激光辐照45#钢板的响应特性进行研究。基于连续光纤激光发射系统,开展钢板的激光辐照实验,得到温度场分布及靶板的烧蚀穿孔特性;基于ANSYS建立靶板有限元模型,模拟激光辐照下靶板的热响应过程,得到了靶板厚度、激光功率和光斑直径等因素对靶板温度分布及靶板穿孔特性的影响规律。     

Numerical studies on four-engine rocket exhaust plume impinging on flame deflectors with afterburning

This paper studies the four-engine liquid rocket flow field during the launching phase. Using three-dimensional compressible Navier-Stokes equations and two-equation realizable k-epsilon turbulence model, an impact model is established and flow fields of plume impinging on the two different shapes of flame deflectors, including wedge-shaped flame deflector and cone-shaped flame deflector, are calcu-lated. The finite-rate chemical kinetics is used to track chemical reactions. The simulation results show that afterburning mainly occurs in the mixed layer. And the region of peak pressure occurs directly under the rocket nozzle, which is the result of the direct impact of exhaust plume. Compared with the wedge-shaped flame deflector, the cone-shaped flame deflector has great performance on guiding exhaust gas. The wedge-shaped and cone-shaped flame deflectors guide the supersonic exhaust plume away from the impingement point with two directions and circumferential direction, respectively. The maximum pressure and temperature on the wedge-shaped flame deflector surface are 37.2% and 9.9% higher than those for the cone-shaped flame deflector. The results provide engineering guidance and theoretical significance for design in flame deflector of the launch platforms.     

铜包钢绞合导体与铜钢混绞导体的耐蚀性比较

通过电化学腐蚀原理的分析,认为被复线用铜包钢绞合导体是用铜钢混绞导体耐蚀性的3倍,有效提高了被复线的野外使用性能.与装备电缆通用的钢丝、铜丝混绞或混编导体或屏蔽层相比,铜包钢丝还兼有更好的耐蚀性、导电性、导磁性和力学性能,是一类优良的电磁屏蔽用导体材料,为装备线缆的设计采用和性能提高提供了防腐依据.     

扩频系统中一种FFT算法的快速捕获方法

针对高动态、大频偏的扩频系统采用了一种基于快速傅氏变换(FFT)算法的伪码快速捕获方法,该捕获方法是在搜索伪码相位的同时,通过频率扫描的方式搜索载波频率偏移值,将原来的伪码相位、载波频偏的二维搜索过程变成只搜索伪码相位的一维搜索过程,从而大大减少了高动态、大频偏扩频系统中的同步伪码的搜索的复杂度。理论分析和仿真结果都证实在不增加硬件复杂度的情况下,基于FFT算法的伪码快速捕获方法能够大幅度地缩短捕获时间,降低系统复杂度。     

高频电磁注入替代辐照耦合装置的设计研究

为提高电磁注入法的应用频带范围,提出基于定向耦合原理的电磁注入方法,并以某天线及其射频前端构成的互连系统为试验对象,利用单定向耦合器作为注入装置进行了辐照和注入试验,试验证明该注入方法能够准确替代连续波辐照效应试验．进而,理论分析耦合装置的特性并对该装置进行改进,提高其工程实用性．最后,设计耦合装置的指标并计算了对应的散射矩阵,制作完成注入装置的样机．结果表明：耦合装置监测端电压与等效源之间的关系会受到受试设备状态的影响．将两单定向耦合器级联作为注入装置,并以监测端的功率作为等效依据,可保证监测结果在高频时不受线缆上驻波的影响,提高试验的准确性．     

油-水旋流器流场数值模拟研究

采用改进后的双方程湍流模型和SIMPLE计算方法,对切流式单入口油-水旋流器内部流场进行了模拟研究。结果表明:旋流器内部三维流场各向异性,即同一位置流体在不同方向的流动参数变化很大,流体质点在不同条件下的运动轨迹、速度、分离特性等方面都有较大差别;圆柱段与圆锥段的流场在柱锥结合面发生变化,旋流器的主要分离过程在圆锥段完成;单入口旋流器的流场中心与几何中心有偏差,对流场的稳定和分离会产生影响。该模拟结果与他人所做实验结果比较接近,说明该模型和算法是可靠的,为旋流器的实际应用提供了参考。     

供油挂车泵机油温度变化规律实验研究

通过实验研究了100 mm野战输油管线供油挂车泵运行时及停运后机油温度随时间的变化规律。采用数据拟合、回归分析等数学方法,分别研究了供油挂车泵空载和带负荷两种情况下机油温度的变化规律;针对供油挂车泵各种工作状态,分析了影响机油温度变化的主要因素,建立了温度变化数学模型。研究结果为100 mm和150 mm野战输油管线供、输油挂车泵机组模拟器的研制提供了一定参考。     

Newsvendor problems with sequentially revealed demand information

This article analyzes a capacity/inventory planning problem with a one‐time uncertain demand. There is a long procurement leadtime, but as some partial demand information is revealed, the firm is allowed to cancel some of the original capacity reservation at a certain fee or sell off some inventory at a lower price. The problem can be viewed as a generalization of the classic newsvendor problem and can be found in many applications. One key observation of the analysis is that the dynamic programming formulation of the problem is closely related to a recursion that arises in the study of a far more complex system, a series inventory system with stochastic demand over an infinite horizon. Using this equivalence, we characterize the optimal policy and assess the value of the additional demand information. We also extend the analysis to a richer model of information. Here, demand is driven by an underlying Markov process, representing economic conditions, weather, market competition, and other environmental factors. Interestingly, under this more general model, the connection to the series inventory system is different. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 2012