diff --git a/examples/maxwell/weak_FEM_BEM_coupling/README.md b/examples/maxwell/weak_FEM_BEM_coupling/README.md index 5e876f9403adc096aeecae03e54f35633d0af697..7b2775dffed50eb68e32646e49c731cbc5071beb 100644 --- a/examples/maxwell/weak_FEM_BEM_coupling/README.md +++ b/examples/maxwell/weak_FEM_BEM_coupling/README.md @@ -1,12 +1,23 @@ -#The electromagnetic transmission-scattering problem +## The electromagnetic transmission-scattering problem Dependencies: * GmshFEM, commit: bd0fb7ebb6b76f0541e25212b9cbcc42e7a0d0b7 * Gmsh, commit: 2db112186d43fab77fca9d2b546c8f76b3ea6169 -* GmshDdm, commit: 1e539b2a25293011fd80a8b0600a2a55c27fdfbf +* GmshDdm, commit: 2a2746ca938924279ad9efbe15e4dc000370ed7f * Bempp-cl, commit: 293135531f385f39ba29cf1c52cc2dba84614e6b + +## Problem description +Let $` \Omega_{-} `$ be a unit sphere (the scatterer) and $`\Omega_{+} `$ the exterior domain. The boundary of $` \Omega_{-} `$ is denoted by $`\Gamma`$. +We consider an incident electromagnetic plane wave propagating in $`\Omega_{+}`$. The total wave field $` \mathbf{E}`$ verifies the following three-dimensional electromagnetic transmission-scattering problem: + +```math +\mathbf{curl}((k_{-}\mathcal{Z}_{-})^{-1}\mathbf{curl }~\mathbf{E})- k_{-}\mathcal{Z}_{-}^{-1}\mathbf{E} = \textbf{0} \text{ ~in~ } \Omega_{-}, \\ +\mathbf{curl}\mathbf{curl }~\mathbf{E}- k_{+}^{2}\mathbf{E} = \textbf{0} \text{ ~in~ } \Omega_{+},\\ +``` +with $` k_\pm`$ and $`\mathcal{Z}_\pm`$ the wavenumbers and the impedances associated with $` \Omega_\pm`$ respectively. The total electric field satisfied the transmission conditions on $`\Gamma`$. For the exterior problem to be well posed and physically admissible, we assume that the scattered field verifies the Silver-Muller radiation condition at infinity. + ## Method overview: The method is an efficient weak coupling formulation between the boundary element method @@ -15,22 +26,6 @@ domain decomposition method involving quasi-optimal transmission operators. The transmission boundary conditions are constructed through a localization process based on complex rational Padé approximants of the nonlocal Magnetic-to-Electric operators (see I. Badia, B. Caudron, X. Antoine, C. Geuzaine. "A well-conditioned weak coupling of boundary element and high-order finite element methods for time-harmonic electromagnetic scattering by inhomogeneous objects". SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2022) -## Problem description -Let ```math \Omega_{-} ``` be a unit sphere (the scatter) and ```math \Omega_{+} ``` the exterior domain. -We consider an incident electromagnetic plane wave propagating in ```math \Omega_{+} ```. The total wave field ```math \mathbf{E}``` verifies the following three-dimensional electromagnetic transmission-scattering problem: -```math -\begin{subequations} -\begin{align} -\curl \left(\frac{1}{k_{-}\mathcal{Z}_{-}}\curl\E\right) - k_{-}\mathcal{Z}_{-}^{-1}\E &= \textbf{0}, \text{ ~in~ } \Omega_{-}, \\ -\curl\curl\E - k_{+}^{2}\E & = \textbf{0}, \text{ ~in~ } \Omega_{+}, \\ -\frac{1}{\iota k_{+}}\curl \textbf{E}_{\textbf{sc}} \times \frac{\textbf{x}}{\left\lVert\textbf{x} \right\rVert}-\textbf{E}_{\textbf{sc}} &= \underset{r \to +\infty}{\mathcal{O}}(r^{-2}), \\ -\boldsymbol{\gamma}^{-}_{t}\E &=\boldsymbol{\gamma}^{+}_ {t}\E, \text{ ~on~ } \Gamma, \\ -\boldsymbol{\gamma}^{-}_{t} \left(\frac{1}{k_{-}\mathcal{Z}_{-}}\curl\E\right) &=\frac{1}{k_{+}\mathcal{Z}_{+}}\boldsymbol{\gamma}^{+}_ {t}\left(\curl\E\right), \text{ ~on~ } \Gamma, -\end{align} -\end{subequations} -``` -with ```math k_\pm``` and ```math \mathcal{Z}_\pm``` the wavenumbers and the impedances associated with ```math \Omega_\pm``` respectively. - ## Installation Run @@ -39,23 +34,24 @@ Run mkdir build && cd build cmake .. make + cd .. ``` ## Usage -Simply run: +Run: ``` - ./example [PARAM] + ./build/example [PARAM] ``` with `[PARAM]`: * `-pade [x]` (with `[x]` equal to 1 or 0) is a parameter to indicate to use Padé or not * `-pointsByWl [x]` where `[x]` is the mesh size. -* `-FEorderAlpha [x]` is the order of the finite element hierarchical basis of the interior electric field. -* `-FEorderAlpha [x]` is the order of the finite element hierarchical basis of some fields. +* `-FEorderAlpha [x]` is the order of the finite element hierarchical basis associated with the interior electric field. +* `-FEorderAlpha [x]` is the order of the finite element hierarchical basis associated with certain fields. * `-help` to display all other available parameters The folder contains * the main script (`main.cpp`) * A python script for the BEM part (`bem.py`) -* The pybind11 folder for information exchange between python and C++ +* A folder for information exchange between python and C++ (`pybind11`)