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近几年美军针对网络电磁空间不断出台新的政策和联合条令,但是相关规定在网络空间作战、电子战、频谱管理行动的定义上有交叠,为了进一步提高作战能力,防止冲突的发生,美军提出网络电磁行动的概念对三者进行整合,针对美军提出的网络电磁行动进行了介绍和分析并提出了对我国的一些启示。 相似文献
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用有限体积法求解三维完全气体的Navier-Stokes方程,并将通量守恒的分区计算方法和B-L湍流模型修正结合在一起,捕捉到了间断处的分离涡、激波、膨胀波等流场信息 相似文献
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EMC是C3I系统的一项重要性能指标。文章从C3I系统EMC实际存在的问题出发, 论述了EMC与EW 的关系及C3I系统EMC值得考虑的若干问题。 相似文献
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为研究前缘转捩对钝前缘三角翼涡结构的影响,采用高阶精度加权紧致非线性格式和γ-Reθ转捩模型对VFE-2中等半径钝前缘三角翼进行数值模拟。将计算结果与试验结果进行详细对比,结果表明:钝前缘三角翼的前缘分离涡发生在翼尖下游,在特定雷诺数下其具体发生位置受转捩因素影响,采用全湍流模型计算会推迟分离,而耦合转捩模型后的计算结果和试验结果吻合良好。运用耦合转捩模型方法,对钝前缘三角翼涡结构随迎角变化进行模拟。计算结果与试验结果吻合,表明在较小的迎角下,前缘不会产生分离诱导涡;随迎角不断增大,分离诱导涡在三角翼后缘附近产生并向上游移动。 相似文献
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《防务技术》2020,16(4):753-761
A hypersonic aerodynamics analysis of an electromagnetic gun (EM gun) launched projectile configuration is undertaken in order to ameliorate the basic aerodynamic characteristics in comparison with the regular projectile layout. Static margin and pendulum motion analysis models have been applied to evaluate the flight stability of a new airframe configuration. With a steady state computational fluid dynamics (CFD) simulation, the basic density, pressure and velocity contours of the EM gun projectile flow field at Mach number 5.0, 6.0 and 7.0 (angle of attack = 0°) have been analyzed. Furthermore, the static margin values are enhanced dramatically for the EM gun projectile with configuration optimization. Drag, lift and pitch property variations are all illustrated with the changes of Mach number and angle of attack. A particle ballistic calculation was completed for the pendulum analysis. The results show that the configuration optimized projectile, launched from the EM gun at Mach number 5.0 to 7.0, acts in a much more stable way than the projectiles with regular aerodynamic layout. 相似文献
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针对传统化学发射的空间碎片清除技术成本过高、难以实施的问题,提出应用地基电磁发射方式的空间碎片清除新方法。通过地面电磁发射的方式以低成本将射弹运送至空间,并通过释放空间微粒云团控制空间碎片离轨,进而实现对空间碎片的清除。由于取消使用占绝大部分成本的化学推进剂,所提出的应用地基电磁发射的空间碎片清除技术为空间碎片低成本清除提供了有效解决途径。 相似文献
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《防务技术》2020,16(2):348-353
The design of solid armature of railgun should take full account of its operating conditions and material properties because the armature is subjected to dynamic loading conditions and experiences a complicated electrical, thermal and mechanical process in the interior ballistic cycle. In this paper present, we first introduced a multi-physical field model of railgun, followed by several examples to investigate the launching process. Especially, we used the explicit finite element method, in which material nonlinearity and geometric nonlinearity were accounted, to investigate the deform behaviors of solid armature. The results show that the dynamic mechanical process of armature is dependent on the armature geometry, material and exciting electric current. By the numerical simulation, the understanding of the fracture mechanism of solid armature was deepened. 相似文献
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《防务技术》2020,16(1):107-118
The phenomenon of static electricity is unpredictable, particularly when an aircraft flying at high altitude that causes the accumulation of static charges beyond a threshold value leading to the failure of its parts and systems including severe explosion and radio communication failure. The accumulation of static charges on aircraft is generated by the virtue of interaction between the outer surface of aircraft and the external environmental attributes encompasses air particles, ice, hail, dust, volcanic ash in addition to its triboelectric charging. In the recent years, advanced polymer-based composites or nanocomposites are preferred structural constituents for aircrafts due to their light weight and comparable mechanical properties, but such composite systems do not render low impedance path for charge flow and are subsequently vulnerable to effect of lightning strike and precipitation static. In this context, it is essential to develop conductive composite systems from non-conductive polymer matrix by nanofiller embodiments. The advent of carbon-based nanocomposite/nanomaterials have adequately addressed such issues related to the nonconductive polymer matrix and further turned into an avant-garde genre of materials. The current review envisioned to illustrate the detailed exploitation of various polymer nanocomposites in addition to especially mentioned epoxy composites based on carbon fillers like carbon black, carbon nanotube (single walled carbon nanotube and multi walled carbon nanotube) and graphene the development of antistatic application in aircraft in addition to the static charge phenomenon and condition for its prevalence in avionic systems. 相似文献