Introduction

Welcome to the Advection Diffusion Reaction (ADR) Solver tutorial for the Nektar++ library. This tutorial is intended to show the main features of the ADR solver in a simple and user-friendly format. If you have not already downloaded and installed Nektar++, please do so by visiting nektar.info, where you can also find the User-Guide with the instructions to install the library. This tutorial requires:

• Nektar++ ADRSolver and pre- and post-processing tools,
• the open-source mesh generator Gmsh,
• the visualisation tool Paraview.

Goals

After the completion of this tutorial, the user will be familiar with:

• the generation of a simple mesh in Gmsh and its conversion into a Nektar++-compatible format;
• the visualisation of the Jacobian distribution across the mesh in Paraview;
• the setup of the initial and boundary conditions, the parameters and the solver settings;
• running a simulation with the ADR solver; and
• the post-processing of the data and the visualisation of the results in Paraview.

Resources

The files necessary to run this tutorial are included in ??. Specifically, two files with extension .xml are needed as input for Nektar++:

• a file containing the mesh: ADR_mesh.xml; and
• a configuration file with the simulation settings ADR_conditions_aligned.xml.

In the same folder it is possible to find also the following additional material:

• a Gmsh file to generate the mesh, ADR_mesh.geo;
• a .msh file containing the mesh in Gmsh format, ADR_mesh.msh;
• a .xml file containing the mesh in Nektar++ format without the edges aligned for the periodic boundary conditions (see section 1.3), ADR_mesh.xml;
• the 11 output .chk binary files generated by running the simulation, ADR_mesh_aligned_i.chk;
• the 11 output files converted in a Paraview readable format (.vtu), ADR_mesh_aligned_i.vtu;
• the output .fld binary file generated at the last time-step of the simulation, ADR_mesh_aligned.fld; and
• a bash script to automatically convert the 11 .chk files into .vtu files, convert.sh.