Bembel

Logo

The BEM-based engineering library

View the Project on GitHub temf/bembel

Bembel

License: GPL v3 GitHub release (latest by date) DOI CircleCI

Table of contents

  1. Introduction
  2. What is a Bembel?
  3. Features
  4. How to Run our Code
  5. Structure of the Repository
  6. Documentation
  7. Known Bugs and Upcoming Features
  8. Publications, Preprints, and how to cite
  9. Contributers
  10. About the People
  11. Funding

1. Introduction

Bembel is the Boundary Element Method Based Engineering Library written in C++ to solve boundary value problems governed by the Laplace, Helmholtz or electric wave equation within the isogeometric framework [3,4,5,6]. It was developed as part of a cooperation between the TU Darmstadt and the University of Basel, coordinated by H. Harbrecht, S. Kurz and S. Schöps. The code is based on the Laplace BEM of J. Dölz, H. Harbrecht, and M. Multerer, [2,7] as well as the spline and geometry framework of F. Wolf. The code was extended by J. Dölz and F. Wolf in early 2018 to cover electromagnetic applications [5,6]. A short introduction to the code has been written [3]. If you utilise our code as part of a publication, we would appreciate it if you cite it.

2. What is a Bembel?

A traditional German ceramic, as depicted in our logo. Quoting Wikipedia:

Most establishments also serve Apfelwein by the Bembel (a specific Apfelwein jug), much like how beer can be purchased by the pitcher in many countries. The paunchy Bembel (made from salt-glazed stoneware) usually has a basic grey colour with blue-painted detailing.

3. Features

Current key features include

4. How to Run our Code

You need to install the Eigen3 library, see Eigen’s Documentation for help. We do not rely on any other external libraries, except for the standard template library. Thus, having installed Eigen, Bembel should run out of the box. If you want to use Bembel as part of your application, simply add the Bembel/ directory to your includes.

If you want to run the provided examples and tests, you can utilize the procided CMakeLists.txt. We recommend setting up a build/ directory in the root directory of the Bembel, to switch to it and then to call cmake .. and make debug or make release, respectively.

The CMake-File checks for installations of Eigen via the corresponding Eigen3Config.cmake. On Unix you may run apt install libeigen3-dev, or on Mac with Homebrew brew install eigen, and everything should work. Alternatively, you can delete the line find_package (Eigen3 3.3 REQUIRED NO_MODULE) and all lines of the type target_link_librarires(... Eigen3::Eigen) from CMakeLists.txt, and give a path to the eigen headers as an include directory manually.

Then, the examples and tests should compile without any issues. You may run all tests by calling make test from the build/ directory after a successful compilation.

The geometry files required to run the examples can be found in the geo/ folder.

5. Structure of the Repository

The general structure of the repository looks as follows.

The Bembel/src/ directory leads to folders corresponding to these modules, which include the actual implementation. The folder examples/ contains short and well documented examples for Bembels functionality and tests/ contains the tests for Bembel.

6. Documentation

A good place to start are the examples in the examples/ folder, together with publication [3]. Apart from that, a Doxygen documentation is available.

7. Known Bugs and Upcoming Features

For a list of known bugs and upcoming features, please have a look at the issue tracker on github.

8. Publications, Preprints, and how to cite

The following articles and preprints influenced the development of Bembel. We appreciate a citation of [3] if you use it in one of your articles.

[1] A. Buffa, J. Dölz, S. Kurz, S. Schöps, R. Vázques, and F. Wolf. Multipatch approximation of the de Rham sequence and its traces in isogeometric analysis. In: Numer. Math., 144, 201-236, 2020. To the paper. To the preprint.

[2] J. Dölz, H. Harbrecht, and M. Peters. An interpolation-based fast multipole method for higher-order boundary elements on parametric surfaces. In: Int. J. Numer. Meth. Eng., 108(13):1705-1728, 2016. To the paper.

[3] J. Dölz, H. Harbrecht, S. Kurz, M. Multerer, S. Schöps, and F. Wolf. Bembel: The Fast Isogeometric Boundary Element C++ Library for Laplace, Helmholtz, and Electric Wave Equation. In: SoftwareX, 11, 10476. To the paper.

[4] J. Dölz, H. Harbrecht, S. Kurz, S. Schöps, and F. Wolf. A fast isogeometric BEM for the three dimensional Laplace- and Helmholtz problems. In: Comput. Methods Appl. Mech. Engrg., 330:83-101, 2018. To the paper. To the preprint.

[5] J. Dölz, S. Kurz, S. Schöps, and F. Wolf. Isogeometric Boundary Elements in Electromagnetism: Rigorous Analysis, Fast Methods, and Examples. In: SIAM J. Sci. Comput., 41(5), B983-B1010, 2019. To the paper. To the preprint.

[6] J. Dölz, S. Kurz, S. Schöps, and F. Wolf. A Numerical Comparison of an Isogeometric and a Parametric Higher Order Raviart–Thomas Approach to the Electric Field Integral Equation. In: IEEE Trans. Antenn. Prop., 68(1), 593–597, 2020. To the paper. To the preprint.

[7] H. Harbrecht and M. Peters. Comparison of fast boundary element methods on parametric surfaces. In: Comput. Methods Appl. Mech. Engrg., 261-262:39-55, 2013. To the paper.

9. Contributors

Contributors include (alphabetically):

10. About the People

11. Funding

Work on Bembel was conducted with the following financial support (alphabetically):