A Study of Three Dimensional Edge and Corner Problems using the neBEM Solver

TL;DR

This paper demonstrates the use of the neBEM solver with triangular and rectangular elements to accurately analyze three-dimensional electrostatic problems involving edges and corners, achieving high precision in capacitance and charge density calculations.

Contribution

The paper introduces exact influence expressions for triangular elements and extends neBEM to handle complex geometries with high accuracy without new formulations.

Findings

Accurate capacitance estimates for complex conductors

Precise charge density distributions at edges and corners

Validation against analytical and numerical results

Abstract

The previously reported neBEM solver has been used to solve electrostatic problems having three-dimensional edges and corners in the physical domain. Both rectangular and triangular elements have been used to discretize the geometries under study. In order to maintain very high level of precision, a library of C functions yielding exact values of potential and flux influences due to uniform surface distribution of singularities on flat triangular and rectangular elements has been developed and used. Here we present the exact expressions proposed for computing the influence of uniform singularity distributions on triangular elements and illustrate their accuracy. We then consider several problems of electrostatics containing edges and singularities of various orders including plates and cubes, and L-shaped conductors. We have tried to show that using the approach proposed in the earlier paper on neBEM and its present enhanced (through the inclusion of triangular elements) form, it is possible to obtain accurate estimates of integral features such as the capacitance of a given conductor and detailed ones such as the charge density distribution at the edges / corners without taking resort to any new or special formulation. Results obtained using neBEM have been compared extensively with both existing analytical and numerical results. The comparisons illustrate the accuracy, flexibility and robustness of the new approach quite comprehensively.