海水中稳恒电流电场的点电极计算模型

根据点电极基本假设,利用均匀介质中稳恒电流场与静电场的相似性,分别采用分离变量法和镜像法计算了点电极稳恒电流场在空气 海水 海床三层介质平行界面模型下的电位分布,从而得到了海水中稳恒电流电场的计算模型.计算结果表明:点电极的电场分布具有明显的特征,可作为舰船电场电极阵列模拟的计算单元.     

基于静止标量磁强计的运动舰船定位问题的研究

建立了静止标量磁强计对运动舰船定位的模型,并给出了用遗传算法求全局较优解、然后用单纯形法进行精确局部搜索的求解参数的方法.仿真实验表明这种方法有效、可行.     

截面为任意形状的长直螺线管的磁场分析

用毕奥 萨伐尔定律和安培环路定理计算了截面为任意形状的无限长均匀密绕载流螺线管内外的磁场分布,其结果和截面为圆形的无限长均匀密绕载流螺线管内外的磁场分布相同.     

火炮装药温度分布的数值模拟

针对火炮弹药的特点,建立了弹药的二维轴对称模型,并在圆柱坐标系下,用控制容积积分法导出一组差分离散格式。采用收敛速度快的块迭代法解代数方程组。实验数据表明数值计算的结果和实测值基本一致,经进一步研究可以用于火炮装药的温度测量。     

电磁主动悬架的建模及仿真研究

根据电磁学原理,利用电磁铁作为主动悬架的作动器,构造出电磁作动器的一般结构.在1/4汽车悬架基础上,建立了电磁主动悬架的非线性模型,应用现代控制理论设计了该模型的次优控制器,对模型进行分析、仿真.结果表明,电磁悬架能够实现一般主动悬架的功能,满足车辆平顺性的要求,可以应用于汽车的悬架系统.     

升压变换装置研制过程中难点问题的解决

结合大功率数字式全电力炮控系统所用的升压变换装置(270 V/32 A)的研制,详细阐述了尖峰电压、偏磁现象、波形振荡产生的机理,并从理论上提出了解决上述问题的方法.研制过程中,通过推挽式变压器的合理设计、控制方案的完善、总体布局的优化等一系列技术措施,较好地抑制了尖峰电压、偏磁、波形振荡的产生;试验结果表明所采取措施的有效性和正确性.     

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。     

Hyperspectral imaging and remote trace detection of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5 d] imidazole (BCHMX) compared with traditional explosives using laser induced fluorescence

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d] imidazole (BCHMX) is an advanced energetic compound that expected to spread worldwide in the near future. Since, no approved remote detection methods were reported in current literature for this material, we performed hyper-spectral imaging and laser induced fluorescence (LIF) to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection systems. For this purpose, an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives, HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane), RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), PETN (2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate). The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 nm. When light source was replaced by a 405 nm laser diode illuminator, a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm². Finally, we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 μg/cm².     

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.