4.3 Time and data input/output control
The OpenFOAM solvers begin all runs by setting up a database. The database controls I/O and, since output of data is usually requested at intervals of time during the run, time is an inextricable part of the database. The controlDict dictionary sets input parameters essential for the creation of the database. The keyword entries in controlDict are listed in Table 4.4. Only the time control and writeInterval entries are truly compulsory, with the database taking default values indicated by † in Table 4.4 for any of the optional entries that are omitted.