Additional history and log information files
NSU3D also produces a set of history or log files which record the time run or convergence histories of various quantities including residuals and force coefficients. At the end of the run, these files are written to the restart.out directory. These are also written to any intermediate restart.# checkpoint directories created during the run. There are two variants for each file: the history based only on the current run (*.out file) and the history based on the current run appended to all previous runs used to restart
the current run (*.restart.out file). In the case where no restart is used for the current run, the *.out and *.restart.out files
will be identical.
All history files are written in a format which is directly readable in TECPLOT. Header lines with run-time information are preceded by a # character which results in them being ignored by TECPLOT.
The set of files includes:
Residual histories and one representative force coefficient history (CL or CZ)
History of wind axis force and moment coefficients (based on no slip boundary condition (RANS) or slip boundary condition (EULER):
History of wind axis force coefficients broken down by pressure and friction components (based on no slip boundary condition (RANS) or slip boundary condition (EULER):
History of grid/body axis force and moment coefficients (based on no slip boundary condition (RANS) or slip boundary condition (EULER):
Note: For ISPAN=1 cases, force3.* and force1.* values will be identical.
History of wind axis force coefficients broken down by geometry components (as specified in *.comp file used in mesh preprocessing):
History of grid/body axis force coefficients broken down by geometry components (as specified in *.comp file used in mesh preprocessing):
History of various flow quantities based on iteration count:
History of various flow quantities based on time step count:
NOTE: These files will be empty for steady-state runs. For time-dependent runs, the *ires.out files record the histories at each subiteration throughout the entire run, while the *istep files record the histories only at each time step.
A total of 64 quantities are monitored in the history* files.
A description of these quantities can be found here (link coming soon).
Mode of operation:
The rplot, force and history files are constructed and logged as follows during an NSU3D run:
1: The values for the current run are temporarily stored in memory as they accumulate and then periodically output to the *.out files. During the run in this manner, the *.out files are located in the ./WRK directory (as opposed to the ./WRK/restart.out directory). These files can be used to plot convergence history while the solver is still running, in order to assess whether the solver should be terminated (using the STOP_RUN file (link)).
2: The frequency for flushing the output to the *.out files is controlled by hardwired parameters (kflush_ires, kflush_istep, kflush_comp_force) which are set in the routine init_io.f. If periodic flushing is not desired, it can be turned off by setting these values to be vary large. However, the dimension of the buffers used to store this info within NSU3D must also be set large enough. Flushing will automatically occur when the size of the buffers exceeds the memory space allocated to these buffers. Buffer sizes are set through parameters mcount_ires, mcount_istep, mcount_comp_force which are set in common_dynamic.f. Flushing is also triggered when ever an intermediate runtime restart file (i.e. checkpointing in response to NCYC_CHECKPT parameter) is written out.
3: At the end of the NSU3D run, the *.out files are moved from the working directory (./WRK) to the restart.out directory. At the same time, if the current run was restarted from a previous solution, the history *.restart.out files contained in the directory used to restart the current solution are copied to the current restart.out directory and the history information from the current run is appended to the restart history information to produce the *.restart.out history files for the current run. In this manner, the *.restart.out files contain all the history including all previous restart runs used to produce the final solution. All history files are thus associated with the current solution values contained in the current restart.out directory and are therefore archived in that directory. This permits their use in future restart runs based on this solution. Additionally, all history files are removed from the current working directory (./WRK) since they are now archived in the restart.out subdirectory. For intermediate runtime restart outputs (i.e. solution checkpointing controlled by the NCYC_CHECKPT parameter), the requisite history files and restart history files are written to the intermediate restart directories labeled restart.#, where # denotes the cycle number of the run.
4: The names for all output directories and files are set in the source code in init_io.f These can be modified at compile time if alternate file names are desired. A list of source code configurable settings can be found here (link).