The following guidelines describes the main algorithm of the Notus program which pilots the overall execution.

Principal simulation algorithm

The principal Notus algorithm is located in the file notus.f90:

1. Setup
   1. Setup MPI communications.
   2. Read the command line.
   3. Write initialization information.

2. Read test case file and initialization

   Each block of the NTS file is read, associated variables and fields are set:

   1. System block
   2. Domain and grid block
   3. Modeling block
   4. Numerical methods block
   5. Post processing block
3. Finalization the initialization stage
   1. Finalize the initialization process
   2. Read the restart file (if requested in the input file)
   3. Write initial data for post-processing visualization

4. Time loop

   The following steps are executed at each time iteration:

   1. If requested, compute time step as a multiple of the CFL.
   2. If requested, prepare next iteration test case (for instance to set time dependent boundary conditions).
   3. Solve the selected equations among navier, energy, species_transport, phase_advection.
   4. Compute physical properties (density, viscosity, etc.) depending of temperature, volume fraction, etc.
   5. If requested, execute a special post processing tool (user post processing or specific to some test cases).
   6. If requested (turbulent flows), compute statistics.
   7. Execute some diagnostics (such as the computation of the Nusselt number, mean velocity magnitude, etc.).
   8. Error measurement.
   9. Stop tests.
   10. Time step switch.
   11. Print state for post-processing visualization.
5. Finalization of the execution
   1. If requested, check and compare the solution to a reference solution for validation purpose
   2. If requested, write grid convergence data