diff --git a/examples/1ptracer/main.cc b/examples/1ptracer/main.cc
index 0325eeac465862445fcd2a6b55c1278cd57cb03d..5ee3a9152df1aa6683003016a33693f849fda4c8 100644
--- a/examples/1ptracer/main.cc
+++ b/examples/1ptracer/main.cc
@@ -30,15 +30,19 @@
// and another one for in- and output.
#include <iostream>
-// Dumux is based on DUNE, the Distributed and Unified Numerics Environment, which provides several grid managers and linear solvers. So we need some includes from that.
+// Dumux is based on DUNE, the Distributed and Unified Numerics Environment, which provides several grid managers and linear solvers.
+// Here, we include classes related to parallel computations, time measurements and file I/O.
#include <dune/common/parallel/mpihelper.hh>
#include <dune/common/timer.hh>
#include <dune/grid/io/file/dgfparser/dgfexception.hh>
#include <dune/grid/io/file/vtk.hh>
-// In Dumux, a property system is used to specify the model. For this, different properties are defined containing type definitions, values and methods. All properties are declared in the file `properties.hh`.
+// In Dumux, the property system is used to specify classes and compile-time options to be used by the model.
+// For this, different properties are defined containing type definitions, values and methods.
+// All properties are declared in the file `properties.hh`.
#include <dumux/common/properties.hh>
-// The following file contains the parameter class, which manages the definition of input parameters by a default value, the inputfile or the command line.
+// The following file contains the parameter class, which manages the definition and retrieval of input
+// parameters by a default value, the inputfile or the command line.
#include <dumux/common/parameters.hh>
// The file `dumuxmessage.hh` contains the class defining the start and end message of the simulation.
#include <dumux/common/dumuxmessage.hh>
@@ -60,7 +64,7 @@ int main(int argc, char** argv) try
{
using namespace Dumux;
- // We define the type tags for the two problems. They are created in the individual problem files.
+ // Convenience aliases for the type tags of the two problems, which are defined in the individual problem files.
using OnePTypeTag = Properties::TTag::IncompressibleTest;
using TracerTypeTag = Properties::TTag::TracerTestCC;
@@ -75,7 +79,11 @@ int main(int argc, char** argv) try
Parameters::init(argc, argv);
// ### Create the grid
- // A gridmanager tries to create the grid either from a grid file or the input file. We solve both problems on the same grid. Hence, the grid is only created once using the type tag of the 1p problem.
+ // The `GridManager` class creates the grid from information given in the input file.
+ // This can either be a grid file, or in the case of structured grids, by specifying the coordinates
+ // of the corners of the grid and the number of cells to be used to discretize each spatial direction.
+ // Here, we solve both the single-phase and the tracer problem on the same grid.
+ // Hence, the grid is only created once using the grid type defined by the type tag of the 1p problem.
GridManager<GetPropType<OnePTypeTag, Properties::Grid>> gridManager;
gridManager.init();
@@ -83,7 +91,7 @@ int main(int argc, char** argv) try
const auto& leafGridView = gridManager.grid().leafGridView();
// ### Set-up and solving of the 1p problem
- // In the following section, we set up and solve the 1p problem. As the result of this problem, we obtain the pressure distribution in the problem domain.
+ // In the following section, we set up and solve the 1p problem. As the result of this problem, we obtain the pressure distribution in the domain.
// #### Set-up
// We create and initialize the finite volume grid geometry, the problem, the linear system, including the jacobian matrix, the residual and the solution vector and the gridvariables.
// We need the finite volume geometry to build up the subcontrolvolumes (scv) and subcontrolvolume faces (scvf) for each element of the grid partition.
@@ -103,13 +111,13 @@ int main(int argc, char** argv) try
auto A = std::make_shared<JacobianMatrix>();
auto r = std::make_shared<SolutionVector>();
- // The grid variables store variables on scv and scvf (volume and flux variables).
+ // The grid variables store variables (primary and secondary variables) on sub-control volumes and faces (volume and flux variables).
using OnePGridVariables = GetPropType<OnePTypeTag, Properties::GridVariables>;
auto onePGridVariables = std::make_shared<OnePGridVariables>(problemOneP, gridGeometry);
onePGridVariables->init(p);
// #### Assembling the linear system
- // We created and inizialize the assembler.
+ // We create and inizialize the assembler.
using OnePAssembler = FVAssembler<OnePTypeTag, DiffMethod::analytic>;
auto assemblerOneP = std::make_shared<OnePAssembler>(problemOneP, gridGeometry, onePGridVariables);
assemblerOneP->setLinearSystem(A, r);
@@ -157,16 +165,17 @@ int main(int argc, char** argv) try
// ### Computation of the volume fluxes
// We use the results of the 1p problem to calculate the volume fluxes in the model domain.
-
using Scalar = GetPropType<OnePTypeTag, Properties::Scalar>;
std::vector<Scalar> volumeFlux(gridGeometry->numScvf(), 0.0);
using FluxVariables = GetPropType<OnePTypeTag, Properties::FluxVariables>;
auto upwindTerm = [](const auto& volVars) { return volVars.mobility(0); };
- // We iterate over all elements.
+ // We iterate over all elements
for (const auto& element : elements(leafGridView))
{
+ // Compute the element-local views on geometry, primary and secondary variables
+ // as well as variables needed for flux computations
auto fvGeometry = localView(*gridGeometry);
fvGeometry.bind(element);
@@ -176,28 +185,17 @@ int main(int argc, char** argv) try
auto elemFluxVars = localView(onePGridVariables->gridFluxVarsCache());
elemFluxVars.bind(element, fvGeometry, elemVolVars);
- // We calculate the volume flux for every subcontrolvolume face, which is not on a Neumann boundary (is not on the boundary or is on a Dirichlet boundary).
-
+ // We calculate the volume fluxes for all sub-control volume faces except for Neumann boundary faces
for (const auto& scvf : scvfs(fvGeometry))
{
- const auto idx = scvf.index();
-
- if (!scvf.boundary())
- {
- FluxVariables fluxVars;
- fluxVars.init(*problemOneP, element, fvGeometry, elemVolVars, scvf, elemFluxVars);
- volumeFlux[idx] = fluxVars.advectiveFlux(0, upwindTerm);
- }
- else
- {
- const auto bcTypes = problemOneP->boundaryTypes(element, scvf);
- if (bcTypes.hasOnlyDirichlet())
- {
- FluxVariables fluxVars;
- fluxVars.init(*problemOneP, element, fvGeometry, elemVolVars, scvf, elemFluxVars);
- volumeFlux[idx] = fluxVars.advectiveFlux(0, upwindTerm);
- }
- }
+ // skip Neumann boundary faces
+ if (scvf.boundary() && problemOneP->boundaryTypes(element, scvf).hasNeumann())
+ continue;
+
+ // let the `FluxVariables` class do the flux computation.
+ FluxVariables fluxVars;
+ fluxVars.init(*problemOneP, element, fvGeometry, elemVolVars, scvf, elemFluxVars);
+ volumeFlux[scvf.index()] = fluxVars.advectiveFlux(0, upwindTerm);
}
}
@@ -244,7 +242,7 @@ int main(int argc, char** argv) try
vtkWriter.write(0.0);
- // For the time loop we set a check point.
+ // We define 10 check points in the time loop at which we will write the solution to vtk files.
timeLoop->setPeriodicCheckPoint(tEnd/10.0);
// #### The time loop
@@ -302,13 +300,15 @@ int main(int argc, char** argv) try
// ### Final Output
-
if (mpiHelper.rank() == 0)
DumuxMessage::print(/*firstCall=*/false);
return 0;
}
+// ### Exception handling
+// In this part of the main file we catch and print possible exceptions that could
+// occur during the simulation.
catch (Dumux::ParameterException &e)
{
std::cerr << std::endl << e << " ---> Abort!" << std::endl;