DT
This floating point variable has to
be set to an elementary time interval.
In order not to degrade the code performance, DT should be set to a
value
much larger than the time step allowed by the CFL criterion. The code
will
split the interval [t,t+DT] in as many time steps as necessary so as to
fulfill
the CFL criterion (this latter is recomputed each time). The last
time step
will be performed so that the new date is exactly t+DT (the
corresponding
time increment can therefore be much smaller than what is allowed by
the
CFL criterion, for this last time step). An output is performed every Ninterm*DT, and the total time over which a
simulation
is run is Ntot*DT. A line is added in the
torque files 'tqwk[i].dat'
every DT, as well as in the planet file 'bigplanet[i].dat' and 'orbit[i].dat' (where i is the planet number), so DT can
be considered as the time interval sampling of all diagnostic files.
At runtime, a dot is sent to the standard output for every elementary
hydrodynamic time step performed. A carriage return is sent every time
a
time interval of length DT has been completed.