大中口径舰炮敏捷供弹系统虚拟样机仿真研究

文中提出了一套完整的大中口径舰炮敏捷供弹系统。应用三维实体建模软件PRO/E完成了整个供弹系统各个子系统的模型设计及建立;进行了装配检查,排除了零部件之间的干涉,完善了零部件设计;再利用PRO/E和ADAMS相结合,建立供弹系统各部分的驱动系统,并与实体模型结合,对此系统进行机构的运动学、动力学和驱动系统仿真,对设计的可行性和合理性进行深入研究.通过以上研究,建立了一个完整的大中口径舰炮敏捷供弹系统虚拟样机,为供弹系统的进一步深入研究以及实际生产提供了坚实的基础,同时给军械设计提供了一条高效率、低成本的设计方法.     

面向信息化战争模拟的体系对抗交互模型研究

从研究信息化战争模拟体系对抗交互模型的有关问题入手,界定了体系对抗交互概念,分析了体系对抗交互的复杂性特征及体系对抗交互作用的主要途径.在探讨体系对抗交互仿真建模内容以及与之相适应的新型建模方法的基础上,对体系对抗总体交互建模、实体交互建模、交互效果建模等问题进行了研究,并给出了有关交互模型的实例.     

非线性随机动态响应的高效模拟方法

提出了一种分析多自由度非线性系统在随机激励下响应的高效模拟方法。该方法以蒙特卡罗方法为基础,针对动态问题,建立了有效的重要性判别准则,采用俄罗斯轮盘赌与分裂方法来处理响应样本,增加了样本在低失效概率区域出现的几率,提高了模拟效率。通过两个算例表明,该方法操作简单,可以大大地减少计算量,能够适用于实际的工程问题。     

带壳体云爆弹药液体燃料抛撒的数值模拟

建立了带壳体云爆弹药数值模拟模型,分析了圆柱壳体的断裂准则。壳体材料采用Johnson-Cook热粘性本构方程,断裂准则采用Taylor断裂应力准则,应用Autodyn软件进行了数值模拟,给出了内部爆炸载荷下液体燃料的压力曲线和速度曲线,并进行了分析。     

随移动窗推进的带电粒子束团长程传输模拟分析

直接采用粒子模拟方法较难实现带电粒子束团千米量级的长程传输模拟,针对此问题以静电模型为基础,引入移动窗技术,使百米量级的粒子传输窗口与束团同步推进运动,建立了带电粒子束团的长程传输模型。将模拟得到的带电粒子束团径向膨胀特性同包络方程的计算结果进行对比,两者吻合较好,证明了在带电粒子束团长程传输模拟研究中结合移动窗技术的可行性及所建模型的合理性。利用此模型分析了100 MeV相对论电子束团的长程传输过程,发现传输过程中束团的自生电场和磁场在径向上呈高度对称分布,轴向上则呈轻微前冲分布;同时,束团内部粒子的轴向速度分布也会发生变化。利用此模型分析了100 MeV电子束团的长程传输过程及其内部参数和自生场量的变化。     

数值模拟气液针栓式火箭发动机喷雾燃烧对声学激励的响应

为研究气液针栓式火箭发动机的声学振荡特性并为其优化设计提供指导,加工了具有矩形燃烧室的LOX/GCH₄针栓式发动机,采用Euler-Lagrange方法仿真横向速度扰动产生的声学响应,以期在热试前了解声学激励频率对非稳态喷雾燃烧过程的影响。仿真结果表明,采用的横向速度扰动能在燃烧室内产生同频率的一阶横向声学振荡响应。喷雾燃烧对声学激励的响应强弱受扰动频率与燃烧室一阶横向振荡模态固有频率的相对大小影响较大。当扰动频率与该固有频率相等时,压力和燃烧释热随速度扰动出现同相振荡,压力振荡幅值显著增高导致燃烧室前半段的喷雾和火焰同步摆动;同时,燃烧室内存在扩散燃烧变为预混燃烧的趋势,甲烷在更短的距离内燃烧完全且燃烧室温度趋于均匀。     

人机共融的远程态势智能感知系统

针对人与远程无人设备协同精准配合的迫切需求,以机器人操作系统为基础构建了一种人机共融的远程态势感知系统,并开展了实验与分析。该系统以视觉定位技术为基础,以人机感知共融为切入点,通过实时三维场景重建技术与场景一致性融合方法,将无人设备探测到的环境及目标信息进行三维重构,并通过增强现实设备进行显示,与人的视觉信息进行一致性融合,实现无GPS条件下远程无人设备与人所佩戴的增强现实设备之间的协同定位。实验结果表明,系统在近距离时具有较好的人机协同定位准确度,定位精度随着距离的增加而逐渐降低。所构建的系统使无人设备成为人眼的延伸,在不干扰人员正常行动的情况下实现了穿障碍、跨视距的感知能力,在未来信息化作战中可发挥重要作用。     

Simulation of the plasticizing behavior of composite modified double-base (CMDB) propellant in grooved calendar based on adaptive grid technology

The frequent occurrence of safety accidents during the calendering process is caused by the flammable and explosive properties of composite modified double-base (CMDB) propellant. Optimization of process parameters with the aid of fluid simulation technology could effectively ensure the safety of the calendering process. To improve the accuracy of the simulation results, material parameters and model structure were corrected based on actual conditions, and adaptive grid technology was applied in the local mesh refinement. In addition, the rheological behavior, motion trajectories and heat transfer mechanisms of CMDB propellant slurry were studied with different gaps, rotational rates and temperatures of two rollers. The results indicated that the refined mesh could significantly improve the contour clarity of boundaries and simulate the characteristics of CMDB propellant slurry reflux movement caused by the convergent flow near the outlet. Compared with the gap, the increased rotational rate of roller could promote the reflux movement and intensify the shear flow of slurry inside the flow region by viscous shear dragging. Meanwhile, under the synergistic effect of contact heat transfer as well as convective heat exchange, heat accumulated near the outlet and diffused along the reflux movement, which led to the countercurrent heat dissipation behavior of CMDB propellant slurry. The plasticizing mechanism of slurry and the safety of calendering under different conditions were explored, which provided theoretical guidance and reference data for the optimization of calendering process conditions. Based on the simulation results, the safety of the CMDB propellant calendering process could be significantly improved with a few tests conducted during a short research and development cycle.     

Mitigation of the blast load effects on a building structure using newly composite structural configurations

In this study, a nonlinear three-dimensional hydrocode numerical simulation was carried out using AUTODYN-3D to investigate the effect of blasting of a high explosive material (TNT) against several configurations of the composite structure. Several numerical models were carried out to study the effect of varying the thickness of the walls and the effect of adding an air layer or aluminum foam layer inside two layers of concrete in mitigating the effect of blast waves on the structure walls. The results showed that increasing the thickness of walls has a good effect on mitigating the effect of blast waves. When a layer of air was added, the effect of blast waves was exaggerated, while when a layer of aluminum foam was added the blast wave effects were mitigated with a reasonable percentage.     

面向两类典型分析仿真的多样本任务调度工具的设计

当在多台计算机上调度很多样本并行运行时,采用手工操作效率低且极易出错。设计一个自动化的任务分发与调度工具可以有效地提高仿真运行效率。蒙特卡罗仿真和粒子群优化算法仿真是两类典型的分析仿真,介绍了面向这两类仿真的多样本任务调度工具的实现原理和关键技术,这些方法具有很好的通用性和可扩展性,可以广泛应用于解决各类仿真任务的自动分发与调度问题。