末端防御武器平台炮控性能检测方法

末端防御武器平台炮控系统性能的好坏直接影响首发命中率和射击反应时间等重要战技指标,在设计试验阶段,对其炮控性能进行检测是必不可少的环节。采用基于三棱锥模型的炮控性能检测方法,建立了三棱锥计算模型并进行Matlab仿真分析以及检测精度分析,从而验证了其工作原理及可行性,满足武器平台炮控性能检测的要求。     

基于不同叶片数目比的烟气涡轮多叶片通道数值模拟

基于定常假设,利用混合平面模型传递级间参数,运用Fluent软件对不同静动叶片数目比下的烟气涡轮多叶片通道流场进行了数值计算,得到了温度、压力、出口速度和马赫数等参数的变化规律,绘制了不同静动叶片数目比下各种参数的体积加权平均XY图,并通过数值分析确定了静动叶片最佳数目比为50∶74,最佳静叶安装角为35°。结果表明:叶片数目增减和静叶安装角的变化对烟气涡轮整体性能的影响须考虑多种因素,并不能以单一参数的变化来决定最佳叶片数目和静叶安装角。该结论可为烟气涡轮现有装备的科学管理和技术改进提供理论依据。     

Poland's national potential and its international position within the European Union – research remarks

This article examines Poland's national potential and its international position within the European Union (EU) with respect to security issues. It presents research results based on a comparison of Poland's national potential as it relates to other EU countries, which is useful when evaluating Poland's power within the EU. The article also evaluates Poland's crisis potential, i.e. it identifies those factors that may potentially be treated as threats to national and regional security. Finally, it enables the identification of challenges to Poland's security in the second decade of the twenty-first century. The research is conducted according to a multidimensional comparative analysis, which is perceived by the author as the best available to measure a country's power despite its weaknesses.     

Planning for the next Takur Ghar

The USA is currently facing an increasingly diverse range of threats, including non-state actors, particularly violent extremist organizations attempting to do harm. The national leadership has made it clear that for the near future it will employ Special Operations Forces (SOF) as the tool of choice in short-duration, high-intensity operations that have more in common with the battle of Takur Ghar, than those with a larger footprint. It is critical then that the lessons of the past are learnt now and are applied before employing SOF in the future. This becomes especially important given the short lead-time in concert with the short-duration/high-intensity tempo of their operations. In the Battle of Takur Ghar, during Operation Anaconda, rigid adherence to the joint functions, especially clearer and more robust Command and Control (C2) and Intelligence, Surveillance, and Reconnaissance (ISR) in the planning and execution of Operation Anaconda would have yielded a better operational outcome and saved lives. With the benefit of hindsight, many things could have been done differently, but several key issues stand out. The C2 structure must include all components from the outset to synchronize effects and rapidly re-task ISR. There must be multiple communications redundancies and adequate bandwidth. Finally, all SOF, conventional and interagency capabilities must be synchronized under one task force commander with a sufficiently robust C2 infrastructure to direct the entire effort. As our nation calls on SOF at an ever-increasing rate, we must take those lessons learned and apply them to future operations.     

基于保障时间窗的油料调拨运输模型

通过引入保障时间窗,同时考虑油料保障的时间约束和运力约束,建立了基于保障开始时间最早,并尽可能满足保障需求量的调度模型。针对问题的多目标性,基于理想点法将初始模型转化为单目标优化模型。采用粒子群算法对模型进行求解,并设计了算法编码和求解步骤。通过算例验证了模型和算法的可行性及有效性。     

基于改进粒子群优化算法的微电网孤岛选址定容

分析了在重要孤立系统中采用微电网供电的必要性,在此基础上提出了采用由非支配排序法和拥挤距离排序法改进的粒子群算法进行微电网选址定容,其目的是改进多目标微电网规划问题的优化结果。通过改进算法与基本算法算例结果的对比分析,验证了改进算法在求解孤岛选址定容问题上具有较强的寻优能力、较高的收敛精度和较稳定的最优解,为进一步研究微电网孤岛选址定容问题提供了思路。     

圆柱壳振动声辐射Jacobi-Ritz时域半解析法及特性分析

针对圆柱壳结构瞬态声振特性分析研究不足,结合Newmark-β积分法和Kirchhoff时域边界积分方程,提出一种圆柱壳受迫振动声辐射Jacobi-Ritz时域半解析法。基于一阶剪切变形理论和微元法思想,建立了圆柱壳振动声辐射分析模型,采取Jacobi多项式和Fourier级数表示轴向和周向位移容许函数,基于Rayleigh-Ritz法和Newmark-β积分法计算圆柱壳的受迫振动时域响应,在此基础上,基于Kirchhoff积分方程求解辐射噪声时域响应,分析圆柱壳受迫振动声辐射特性。与有限元方法/边界元方法数值结果对比表明,该方法具备收敛性好、精度高等优点,圆柱壳结构声振响应峰值随边界条件的刚度变弱存在左移现象,振动声辐射响应随厚度的增加呈现下降趋势;当随机载荷峰值频率与结构固有频率接近时,结构声振响应出现强特征线谱。     

多基准站相对定位算法及先验基线向量偏差影响分析

为提高单基准站短基线相对定位解算的可靠性,研究了多基准站约束的相对定位算法。将基准站间可提前测量的先验基线信息融入观测模型中,给出了多基准站相对定位的函数模型和随机模型,在此基础上推导了模糊度精度因子的解析表达式,揭示了基准站数量的增加对模糊度浮点解精度提升的作用;从理论上分析了基准站间先验基线信息中的偏差对模糊度解算的影响,分析表明,当先验基线各分量偏差的绝对值之和小于5 cm时,模糊度解算几乎不受影响;通过仿真和实测数据进行了验证。试验结果表明,增加基准站数量不仅能有效提升模糊度解算成功率和收敛速度,并且对先验基线信息中的偏差具有较好的抑制作用,当基线各分量偏差均增加到4 cm时,实测数据模糊度解算成功率仍能达到92%以上。研究结论为特殊场景下多基准站间的快速非精确标定提供了理论依据。     

超音速环形引射器空气引射启动特性试验

建立了超音速环形引射系统,对环形引射器空气引射启动特性进行了试验研究.试验结果表明:管道马赫数越大,则系统启动压强越高,同时盲腔真空度越高;混合室收缩比越小,系统启动压强越低;若管道马赫数较大,而第二喉部长径比和亚音速扩压段面积比过小,引射器启动过程可能不稳定,甚至无法启动;混合室收缩比、环型引射器扩压管道参数对盲腔压强无影响.     

空间引力波探测无拖曳技术现状与趋势

航天器无拖曳控制是实现引力波空间探测科学平台超静超稳运行的核心关键技术之一。目前,国内外各研究机构对航天器系统的动力学与控制进行了深入研究,并针对不同的探测频段需求提出了不同的探测任务。根据探测任务进行了航天器编队设计与控制的详细介绍和分析,对涉及的无拖曳与姿态控制、高精度惯性传感器与执行机构等原理和理论方法进行了深入的剖析。针对现已开展的空间引力波探测无拖曳航天器在轨飞行的演示验证整体情况进行详述和分析。在此基础上,提出后续开展相关研究中亟待解决的关键问题,指出未来无拖曳航天器系统动力学与控制的研究热点和趋势。