output Output

The Output Panel controls both the types of data written to disk and the frequency at which that data is generated for analysis and visualization. Output data includes all information produced by the solver, such as statistics files, two- and three-dimensional rendering data, particle visualizations, and static or moving body surface forces. This panel also controls the checkpoint (restart) file output frequency, which is used to restart or continue simulations.

The output panel can contain up to eight tabs, depending on the composition of the model.

  • Statistics: The statistics tab shows which text-based simulation data (such as forces, concentrations, temperatures, velocities, and blending results) will be written during a run.

  • Planes/Probes: The output planes tab control the timed and conditional export of visual simulation data (such as VTK slices, planes, particles, and free or moving surfaces) to support real-time animation and post-processing of flow and transport behavior.

  • Volumes: Output volume controls when full-domain volume data are written, using time-based or conditional triggers to balance file size, disk I/O cost, and temporal resolution during post-processing.

  • Fluid: Output fluid defines the volume-of-fluid (VOF) isosurface contour value used to extract and visualize the fluid interface in the simulation.

  • Static Bodies: Output static bodies controls the calculation and export of forces, time-averaged forces, wetted area, and wall-function metrics on static geometry, with optional diagnostics that increase mesh and memory requirements.

  • Moving Bodies: Output moving bodies controls the export of time-averaged stress and volume fraction data for moving bodies to support detailed analysis of their fluid–structure interactions.

  • Bubbles/Particles: Output bubbles/particles controls how particle and bubble data are written, including output down-selection, exit tracking, and customized write intervals for efficient, targeted post-processing.

  • Restart Files: Output restart files controls the creation of binary checkpoint files used to restart simulations, including their timing, conditional output, and retention, balancing disk usage with recovery capability.

Output File Formats

Output data can be divided into three categories: ASCII text files, VTK visualization files, and HDF restart files. The Statistics data are saved as ASCII text files. ASCII text files are tab-separated columns of data used for plotting or post-analysis. These files are human-readable and can be opened with any standard text editor or plotting software. The Plane/Probe, Volume, Fluid, Static Body, Moving Body and Bubble/Particle data are all stored in the VTK file format. VTK files are binary files used for 2D and 3D rendering and visualization. They can be opened in M-Star Post or other software that supports the VTK format. The Restart Files are HDF checkpoint files used to restart simulations. They contain the complete state variables of the entire system. These binary files can only be read by M-Star Solve.