Introduction#

This library is conceived to be a collection of solvers to be used in OpenFOAM-v6.

Four algorithms have been implemented (with their extensions):

  1. Proper Orthogonal Decomposition (POD): with projection for the online phase

  2. Empirical Interpolation Method (EIM)

  3. Generalised Empirical Interpolation Method (GEIM)

  4. Parameterised-Background Data-Weak (PBDW) formulation

Moreover, some useful routines have been implemented in the src/MOR/MOR folder to compute the following:

  • Scalar product in \(L^2\) for scalar and vector fields:

\[\begin{equation*} \langle \phi, \psi\rangle = \int_\Omega \phi \cdot \psi\,d\Omega \qquad \qquad \langle \mathbf{u}, \mathbf{v}\rangle = \int_\Omega \mathbf{u} \cdot \mathbf{v}\,d\Omega \end{equation*}\]
  • Norm in \(L^2\) for scalar and vector fields:

\[\begin{equation*} \|\phi\|_{L^2}^2=\int_\Omega \phi^2\,d\Omega \qquad \qquad \|\mathbf{u}\|_{L^2}^2=\int_\Omega \mathbf{u}\cdot \mathbf{u}\,d\Omega \end{equation*}\]
  • Norm in \(H^1\) for scalar and vector fields:

\[\begin{equation*} \|\phi\|_{H^1}^2=\int_\Omega \phi^2\,d\Omega + \int_\Omega \nabla\phi\cdot \nabla \phi\,d\Omega \qquad \qquad \|\mathbf{u}\|_{H^1}^2=\int_\Omega \mathbf{u}\cdot \mathbf{u}\,d\Omega + \int_\Omega \nabla\mathbf{u}: \nabla \mathbf{u}\,d\Omega \end{equation*}\]
  • Norm in \(L^\infty\) for scalar and vector fields:

\[\begin{equation*} \|\phi\|_{L^\infty} =\max\limits_\Omega |\phi|\qquad \qquad \|\mathbf{u}\|_{L^\infty} =\max\limits_\Omega \|\mathbf{u}\|_2 \end{equation*}\]