坦克射击三维视景实时立体显示研究

通过对人体生理学和计算机图形学的分析,阐述了三维视景实时立体显示的原理,提出了实现方法,并基于 AGC—ProV三维图形卡,对三维视景实时立体显示开发进行了论述.     

Gas metal arc welding of high nitrogen stainless steel with Ar-N2-O2 ternary shielding gas

High nitrogen stainless steel with nitrogen content of 0.75％was welded by gas metal arc welding with Ar—N2-O2 ternary shielding gas. The effect of the ternary shielding gas on the retention and improvement of nitrogen content in the weld was identified. Surfacing test was conducted first to compare the ability of O2 and CO2 in prompting nitrogen dissolution. The nitrogen content of the surfacing metal with O2 is slightly higher than CO2. And then Ar—N2-O2 shielding gas was applied to weld high nitrogen stainless steel. After using N2-containing shielding gas, the nitrogen content of the weld was improved by 0.1 wt％. As N2 continued to increase, the increment of nitrogen content was not obvious, but the ferrite decreased from the top to the bottom. When the proportion of N2 reached 20％, a full austenitic weld was obtained and the tensile strength was improved by 8.7％. Combined with the results of surfacing test and welding test, it is concluded that the main effect of N2 is to inhibit the escape of nitrogen and suppress the ni-trogen diffusion from bottom to the top in the molten pool.     

Hazard evaluation of ignition sensitivity and explosion severity for three typical MH2 (M＝Mg,Ti, Zr) of energetic materials

MgH2, TiH2, and ZrH2 are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent years. To evaluate ignition sensitivity and explosion severity, the Hartmann device and spherical pressure vessel were used to test ignition energy and ex-plosion pressure, respectively. The results showed that the ignition sensitivity of ZrH2, TiH2 and MgH2 gradually increased. When the concentration of MgH2 is 83.0 g/m3 in Hartmann device, the ignition energy attained a minimum of 10.0 mJ. The explosion pressure of MgH2 were 1.44 times and 1.76 times that of TiH2 and ZrH2, respectively, and the explosion pressure rising rate were 3.97 times and 9.96 times that of TiH2 and ZrH2, respectively, through the spherical pressure vessel. It indicated that the reaction reactivity and reaction rate of MgH2 were higher than that of TiH2 and ZrH2. In addition, to conduct in-depth theoretical analysis of ignition sensitivity and explosion severity, gas production and combus-tion heat per unit mass of ZrH2, TiH2 and MgH2 were tested by mercury manometer and oxygen bomb calorimetry. The experimental results revealed that MgH2 had a relatively high gas production per unit mass (5.15 mL/g), while TiH2 and ZrH2 both had a gas production of less than 2.0 mL/g. Their thermal stability gradually increased, leading to a gradual increase in ignition energy. Furthermore, compared with theoretical combustion heat, the combustion ratio of MgH2, TiH2 and ZrH2 was more than 96.0%, with combustion heat value of 29.96, 20.94 and 12.22 MJ/kg, respectively, which was consistent with the explosion pressure and explosion severity test results.     

Numerical and experimental study on the response characteristics of warhead in the fast cook-off process

The response characteristics of the warhead under thermal stimuli conditions are important to the safety improvement. The goal of this study is to obtain data on the warhead in the fast cook-off process. In this paper, a numerical calculation method is proposed, whose reliability is supported by comparison with experimental results. Through the numerical calculation, the temperature distribution, temperature change, and ignition time are acquired. The numerical results show that the ignition time is 76 s after the warhead started to burn and that the maximum temperature of the explosive's outer surface is 238.3 C at the ignition time. The fast cook-off experiment of the warhead is implemented so as to get the flame temperature and reaction grades that are not available through numerical calculation. The experimental results show that the overpressure fails to reach the preset minimum value which is equivalent to 6 kg of TNT and that the reaction grade is deflagration. The research results have reference value for the design of the warhead and the reduction of detonation risks.     

A reusable planar triggered spark-gap switch batched-fabricated with PCB technology for medium-and low-voltage pulse power systems

Triggered spark-gap switch is a popular discharge switch for pulse power systems. Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems. Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion. Additionally, these switches did not employ any structures in securing internal gas composition, resulting in inconsistent performance under harsh atmospheres. In this work, a novel planar triggered spark-gap switch (PTS) with a hermetically sealed cavity was batched-prepared with printed circuit board (PCB) technology, to achieve reusability with low cost. The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision. The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times. The calculated switch voltage and circuit current were consistent with those derived from real-world measurements. Finally, PCB PTS was used to introduce hexanitrostilbene (HNS) pellets in a pulse power system to verify its performance.     

阻燃型宽温域阻尼材料的分子设计

本文在大量研究成果的基础上,从材料分子结构的角度提出了阻燃型阻尼材料分子设计的两个关键问题,一是拓宽材料的玻璃化转变范围,二是采取合理的阻燃措施。     

核动力折中稳态运行方案下稳压器压力控制的模糊控制器

运用模糊控制理论,针对稳压器压力控制的特点,为解决核动力装置折中稳态运行方案下低工况运行时一回路压力随负荷变化波动较大的问题,设计了压力模糊控制器。即利用模糊控制器实现稳压器压力调节系统工作参数的在线优化自整定,并以某核动力装置为对象进行了仿真实验。仿真结果表明,本控制器在对原系统不作大改动的前提下,能有效地抑制一回路压力波动,比原有调节系统具有好得多的调节品质。     

自适应跳频通信受扰信道无源确认技术

及时确认被干扰信道是自适应跳频通信躲避干扰的前提。本文提出了一种受扰信道无源自适应预测评估算法 ,无需发射信号就可以识别干扰信道并预先躲避 ,从而提高了系统的抗干扰性能 ,方法简单 ,易于实现。     

高炮武器训练/评价模拟系统设计方案

系统地介绍了高炮武器训练／评价模拟系统的设计方案。本系统是一套用于模拟高炮射击并评价射击效果的半物理仿真系统。它可以作为雷达、指挥仪、高炮的操作手和指挥员的基本操作训练,模拟真实射击环境,对空中目标进行跟踪和射击之用,也可用于高炮火力综合体的性能评估。     

柱体大攻角入水弹道建模与仿真

基于CFD计算获得了柱体大攻角入水过程流体动力特性,进而建立了大攻角入水弹道模型,使用流场-弹道耦合计算结果验证了模型的适用性和精度,然后仿真分析了入水攻角和速度对入水弹道的影响规律。该模型能较准确地预测柱体大攻角入水弹道,对研究发射平台安全性问题和空投鱼雷等入水攻击性武器的入水弹道预测问题等有较强的指导意义。