All output files generated by PetIBM during a simulation are by default saved into the folder output of the current working directory. The path of the output folder can be configured via the command-line option -output <path of the folder>; the path is relative to the current working directory.

List of output files:

grid.h5: HDF5 file containing the gridline stations in the x, y, and z directions (datasets x, y, and z) for each fluid variables (group p for the pressure and groups u, v, and w for the velocity components).
forces-<idx>.txt: ASCII file that contains the hydrodynamic forces acting on the immersed body at each time-step. (<idx> in the file name is replaced by the initial time-step index of the run.) The first column contains the time values. The next two columns (or three columns for 3D runs) contains the forces in the x and y directions (and in the z direction for 3D runs). If there is a second immersed boundary in the domain, the force columns will be append to the right. (Note that this file does not exist for pure Navier-Stokes simulations, i.e. when there is no immersed boundary in the computation domain.)
iterations-<idx>.txt: ASCII file reporting the number of iterations to converge and the residuals for each linear solver: velocity solver, Poisson solver, and forces solver (when using the decoupled version of the immersed-boundary projection method). (<idx> in the file name is replaced by the initial time-step index of the run.) The first column contains the time-step index; the second and third columns contains the number of iterations to converge and the residuals for the first linear solver (velocity); etc.
<timestep>.h5: HDF5 file containing the numerical solution at a specific time step. The frequency of saving is prescribed in the YAML configuration file via the parameter nsave. For example, the numerical solution after 100 time steps is saved in the file 0000100.h5. The velocity field, the pressure field, the boundary forces (when bodies are present in the domain). In addition, the convection and diffusion terms are also saved in the file when the time-step index is a multiple of nrestart (which can be defined in the YAML configuration file); these terms will be used to restart a simulation from a non-zero time-step index.
logs: folder containing PETSc logging files saved at certain time steps. (Whenever the numerical solution is written into a HDF5, we also save the PETSc logging information of the run.)