Fast Fourier transform-volume integral: a smart approach for the electromagnetic design of complex systems in large fusion devices

Abstract

A volume integral (VI) equation method based on the fast Fourier transform (FFT) is proposed for the electromagnetic simulation of complex systems in large magnetic confinement fusion (MCF) devices. Such FFT-VI allows for dramatically reducing the time and the human effort required to adapt the CAD input files to models suited for electromagnetic simulations. Moreover, with FFT-VI the mesh generation is performed automatically and is very efficient and robust. The adoption of the FFT allows for significantly reducing the computation time and the memory requirements, therefore making simulations with several millions of unknowns feasible. Numerical results show that, in terms of numerical performances, the FFT-VI method applied to challenging electromagnetic problems in representative MCF devices is markedly superior with respect to the state of the art VI techniques. A sample implementation of FFT-VI is made publicly available.

A fast tool for the parametric analysis of human body exposed to LF electromagnetic fields in biomedical applications

“…First, in Section 2.1, the formulation is shortly described. Then, in Section 2.2, the discretization procedure is performed according to [33,31,32] in order to exploit the translational invariant property of the integral kernel, drastically speeding-up the simulation and dramatically reducing the memory requirement.…”

“…Then, in Section 2.3, a solution technique based on an Algebraic Multigrid (AMG) preconditioner is presented, leading to a significant reduction of the overall computational cost required by humanbody EM simulations [32,34].…”

“…where R and L are the (sparse) resistance and (dense) inductance matrices, respectively, whose coefficients are given in [32]. In (7), G is the volumes-faces incidence matrix whereas e ext is the array corresponding to the incident external electric field, and j ext is the array corresponding to injected currents (which can be used to model human model connections to electrodes injecting positive or negative currents).…”

“…The proposed formulation takes advantage of the regularity of this discretization by reducing the memory requirement and speeding-up the computational procedure. Moreover, it exploits recent advancements in the solution of IE by means of iterative preconditioned solvers [31,32].…”

Digital Visual Sensing Design Teaching Using Digital Twins

“…It converts the measured quantity into a certain physical quantity convenient for application according to a certain law. A sensor includes the sensitive element, conversion element, and measuring circuit [6]. It has four concepts, and one of them is the working principle of the sensor, as shown in Figure 2.…”