ThinCurr: An open-source 3D thin-wall eddy current modeling code for the analysis of large-scale systems of conducting structures

TL;DR

ThinCurr is an open-source 3D thin-wall eddy current modeling tool designed for large-scale, complex conducting structures in plasma devices, combining advanced numerical methods with user-friendly features.

Contribution

The paper introduces ThinCurr, a novel open-source code that integrates boundary finite element methods with hierarchical low-rank compression for scalable, accurate modeling of eddy currents in large, complex systems.

Findings

Validated against VALEN and Ansys software.

Achieves scalability for large models.

Provides accurate simulation of inductively-coupled currents.

Abstract

In this paper we present a new thin-wall eddy current modeling code, ThinCurr, for studying inductively-coupled currents in 3D conducting structures -- with primary application focused on the interaction between currents flowing in coils, plasma, and conducting structures of magnetically-confined plasma devices. The code utilizes a boundary finite element method on an unstructured, triangular grid to accurately capture device structures. The new code, part of the broader Open FUSION Toolkit, is open-source and designed for ease of use without sacrificing capability and speed through a combination of Python, Fortran, and C/C++ components. Scalability to large models is enabled through use of hierarchical off-diagonal low-rank compression of the inductance matrix, which is otherwise dense. Ease of handling large models of complicated geometry is further supported by automatic determination of supplemental elements through a greedy homology approach. A detailed description of the numerical methods of the code and verification of the implementation of those methods using cross-code comparisons against the VALEN code and Ansys commercial analysis software is shown.