Hybrid Simulation of Electromagnetic Field Interaction with Metallic Structures Showing Massive Nonlinear Loading

该项目的目标是在三个不同研究领域的交叉领域做出科学贡献：(1)电磁场与非线性载荷、电大尺寸结构和表面相互作用的物理，(2)此类结构和表面的新工程应用，以及(3)此类结构和表面的高效和稳定的数值建模和模拟。金属结构的大规模加载，即数百个非线性负载在一个很大的电面积上的连接，近年来引起了人们的高度关注，并给基础研究带来了新的挑战和机遇。这些结构和表面可以预见或已经看到的例子和应用包括能量选择性屏蔽、波形相关吸收、表面波的自聚焦、RF限幅器、亚波长成像、非线性雷达和开关、以及时间域窗口等等。由于这种高度的兴趣，很可能在不久的将来，对用于非线性载荷结构和表面的设计和优化的高效和有效的数值方法的需求将会越来越大。基于汉堡理工大学(TUHH)舒斯特教授和都灵理工大学(Polito)Griveet-Talocia教授团队之前的工作，提出了一种新的混合模拟技术来解决这一需求。该技术将使用基于积分方程式的矩量法(MoM)来描述问题的线性部分(即金属结构和表面)，并结合模型降阶(MOR)和波形松弛(WR)来处理包含许多非线性载荷的完整系统。研究的挑战在于如何将这些著名的方法(MOM、MOR、WR)进行适当的组合和适应，以满足大规模非线性载荷(即1000个或更多的非线性载荷)、电大尺寸结构和表面的数值模拟对精度、稳定性和效率的要求。

The proposed project aims to contribute scientifically at the intersection of three different research areas: (1) the physics of electromagnetic field interaction with nonlinearly loaded, electrically large structures and surfaces, (2) novel engineering applications for such structures and surfaces, and (3) efficient and stable numerical modeling and simulation of such structures and surfaces. The massive loading of metallic structures, i.e. the connection of several hundreds of nonlinear loads over an electrically large area, has been of high interest in the recent past and poses new challenges and opportunities for fundamental research. Examples and applications that are foreseen or already looked at for these kind of structures and surfaces include energy-selective shielding, waveform-dependent absorption, self-focusing of surface waves, RF limiters, subwavelength imaging, nonlinear radar and switching, and time-domain windowing among others. Due to this high interest it is very likely that there will be an increasing demand for efficient and validated numerical methods for design and optimization of nonlinearly loaded structures and surfaces in the near future. Based on previous work of the groups of Prof. Schuster at Hamburg University of Technology (TUHH) and the group of Prof. Grivet-Talocia at Politecnico di Torino (POLITO) it is proposed to generate a novel hybrid simulation technique addressing this need. The technique will use the integral equation based Method of Moments (MoM) for characterization of the linear part (i.e. the metallic structures and surfaces) of the problem and a combination of Model Order Reduction (MOR) and Waveform Relaxation (WR) for dealing with the complete system including many nonlinear loads. The research challenge lies in the suitable combination and adaption of these well-known methods (MoM, MOR, WR) for meeting the demands on accuracy, stability, and efficiency of the numerical simulation of massively nonlinearly loaded (i.e. 1000 and more nonlinear loads), electrically large structures and surfaces.