复杂平台下相控阵天线近场快速求解算法研究实现

提出基于高频算法的求解相控阵天线近场的快速求解方案。建立相控阵天线子阵列模型,成功应用有源单元法获取单个阵元在考虑耦合情况下的方向图特性数据。给出镜像源法在多三角面片上的射线寻径的实现方法,并成功获取了射线路径。提出基于面片的实时空间区域二分算法的射线寻径加速方法,加速射线寻径过程,提升了程序计算效能,能够快速获取较精确的相控阵天线近场。     

相控阵天线波束指向跟踪算法研究

根据舰载环境的特点,提出一种改进的由计算机控制相控阵天线跟踪波束指向的算法.仿真结果表明,该算法可显著地提高对目标的跟踪性能,并且计算量小,比较适合工程化.     

应用于舰载天线电磁兼容性分析的改进多层快速多极子算法

为解决舰载天线间互相干扰的问题,准确预测舰载天线在装舰前的电磁兼容性,在矩量法（MoM）的基础上,引入一种改进的新型算法,该算法应用多层快速多极子（MLFMA）技术, 并构造谱域两步预处理器结合广义最小留数法（GMRES）来加速矩阵矢量乘的求解。应用FEKO软件对某驱逐舰进行电磁建模,使用该算法对天线方向图及天线间的耦合度进行数值仿真。仿真结果表明：这种新的算法相比于原算法计算速度更快、内存占用更低、准确性更高,可显著减少方程组的迭代次数,改善矩阵方程的收敛性。     

基于矢量阵的近场小目标定位算法研究

针对水下近场预警问题,本文提出利用任意阵型的矢量水听器阵列对近场小目标声源定位。本文首先详细推导了平面矢量阵的近场测量模型,然后介绍了矢量阵常规波束形成和MVDR算法,最后通过仿真和实验进行验证算法的性能。结果表明矢量阵MVDR具有更高的目标分辨率,RMSE随SNR的增大误差不断减小,适合于水下近场区域预警防御。     

An experimental study on the dynamic response of a hull girder subjected to near field underwater explosion

An experiment of hull girder model subjected to near field underwater explosion at midship is implemented. High-speed photography is applied to achieve the time history of hog displacement of the hull girder model subjected to shock wave of undex. The determination method of hog distortion using these show-motion pictures is presented. The experiment also achieves the local plate distortion of the hull girder model. Based on these works, the damage mechanism and mode of hull girder subjected to near field undex at midship are discovered. Finally, the coupling effect between whole motion of hull girder and distortion of local structure is discussed.     

基于函数语言的并行FDTD算法新实现及其在航空母舰甲板表面电磁场分布问题仿真中的应用

传统的基于过程语言的算法实现很难应用于大规模并行计算,OpenMP和MPI等现有并行框架存在着并行实现困难、开发成本大和灵活度差等诸多问题。通过应用基于函数语言的并行新方法,有效简化并行代码的设计,提升并行算法的开发自由度,并可支持动态分区等复杂并行需求。通过将其应用于具有天然并行属性的FDTD剖分及仿真算法,发现可实现高达50%加速比的高效并行,并在26 h内成功求解高达6.9亿未知量的电大尺寸航空母舰甲板模型电磁全波仿真问题。     

An updated fast continuous contact detection algorithm and its implementation in case study of ice-structure interaction by peridynamics

Peridynamics is a mesh-free particle method that has been proposed in the last two decades. Contact between bodies in Peridynamics is a challenging and critical phenomenon that not only affects the computational efficiency of the algorithm, but is also closely related to the accuracy of the calculations. Therefore, it is important to develop a contact detection algorithm that is efficient, accurate, easy to extend to coupled numerical methods, and conducive to parallel computation. This study proposes a fast and continuous contact detection algorithm (FCCDA) that consists of two main parts. The first involves establishing a regular box bounding the entire target of collision to avoid the unnecessary calculation of material points that are not in contact with it, where this critically reduces the number of time-consuming calculations. The second part is a graphics-based algorithm to identify specific particles that penetrate the target. Both the numerical strategies and the mathematical methodologies of the FCCDA are discussed here. It was embedded into a Peridynamics system and examined in the context of a benchmark case for verification. Ship–ice interaction and propeller–ice interaction are also demonstrated using the proposed algorithm as examples of its applications to engineering.