Restart File Description

A restart.n file is generated by default at the conclusion of every execution and otherwise when requested in the Output Control Card with the Plot File Output Times input items. If a file named restart.n (where n refers to the time step extension) already exists in the current directory then the file will be erased and overwritten. The user is responsible for renaming previous restart.n files prior to executing the simulator. The user has the option to specify “no restart” or “final restart” as a plot variable. This can be useful for large problems with a large number of requested outputs.

Header

A restart file begins with a welcome statement, disclaimer, and banner, which should appear similar to

Data

All data values in restart files are in SI units with pressures expressed in gauge. The first data line of a restart file contains the following timing and simulation information: time, time step, maximum time step, minimum time step, time step acceleration factor, convergence criterion, time step cut factor, maximum number of Newton-Raphson iterations, number of time steps, and number of nodes, number of solutes, operational mode, and the solution control indices. The remaining lines are nodal data lines containing field variable data for the current time step for every node (one line per node). The variables written to the restart file are operational mode dependent, but they comprise the complete set of information needed to represent the state of the simulation at that timestep so that upon restart, the intial conditions are those of the saved timestep. All nodal data lines are terminated with an integer value for the phase condition.