Output Control Panel¶

Output Options for a simulation can be brought up by clicking the Output button on the main tool bar. This presents a multi paged configuration dialog with all output related options. Generally the pages are broken up by object type.

Statistics¶

The time interval at which text data is printed to the disk [Seconds]

Data output refers to text-only data, including forces, torques, species concentrations, system temperatures, inlet/outlet velocities, blending results, etc.

In general, text data should be output every 20-100 timesteps to properly balance the computational cost associated with printing the data with the need for sufficient temporal resolution during post-processing.

See Output Data Structure for a complete list of the output files produced by the solver.

Write Time Interval: Interval at which the statistics write will occur. Can be a UDF.
Start Time: Start time of statistics writes
Output Condition: Statistics can be output ad hoc at runtime. Use this expression to set the “output” variable to true at specific times.

Planes¶

Time in seconds between VTK slice, surface, and particle output [Seconds]

Slice output refers to visual data output, including planes, particles, free surfaces, and moving surfaces. Slice data can be rendered as a movie or converted into a spreadsheet to analyze flow fields/transport.

In general, slice data should be output every 100-1000 timesteps to properly balance the computational cost associated with printing the data with the need for sufficient temporal resolution.

See Output Data Structure for a complete list of the output files produced by the solver.

When producing real-time animations using slice, particle, or free surface data, the animation frame rate should match the Slice Output Interval value set here to produce a real-time animation.

Write Time Interval: Interval at which the plane/slice writes will occur. Can be a UDF.
Start Time: Start time of plane/slice writes
Output Condition: Plane data can be output ad hoc at runtime. Use this expression to set the “output” variable to true at specific times.

Volumes¶

Tip

These files can be large. To minimize the size of these files, consider downselecting data channels and reducing output frequency

In general, volume data should be output every 1,000-10,000 timesteps to properly balance the computational cost associated with writing the data to disk with the need for sufficient temporal resolution.

Write Time Interval

Interval at which the volume writes will occur. Can be a UDF.

Start Time

Start time of volume writes

Output Condition

Volume data can be output ad hoc at runtime. Use this expression to set the “output” variable to true at specific times.

Stop Time

End of simulation
Custom stop time

Restart/Checkpoint Files¶

These files are used to restart a simulation.

In addition to these user-specified intervals, a final checkpoint file

is produced at the last simulation timestep.

Checkpoint files are binary internal files that cannot be visualized or post-processed. Data for post-processing is printed at the Data, Slice, and Volume Output Intervals.

In general, the checkpoint interval can be much larger than any output data frequency.

Write Interval

The interval at which to save checkpoint files

Number of Check Points Kept

Number of the most result check point files to keep. The solver retains only this number check points in order to save disk space. For example if this value is set to 3, when the solver writes the 4th restart file, the oldest restart file will deleted, in order to maintain a maximum of 3 check point files.

Start Time

Start time of writes

Output Condition

Restart data can be output ad hoc at runtime. Use this expression to set the “output” variable to true at specific times.

Fluid¶

VOF isosurface contour value: The volume of fluid isosurface value. Must be between 0 and 1.

Static Bodies¶

Enable Output Forces: Compute and output force data on static bodies
Enable Output Time Avg Forces: Compute time averaged forces on static bodies
Compute Wetted Area: Compute wetted area
Enable Y Plus: Compute Y plus values on static bodies

Moving Bodies¶

Time Avg Stresses: Enable time average stress on moving body
Volume Fraction: Enable volume fraction output for moving body

Particles/Bubbles¶

Down Selection: Use this parameter to down select particle output to every Nth particle
Exit Statistics: Track and report exit statistics for particles when they leave the domain
Enable Particle Writes Config: Customize the write interval for particles/bubbles. This will override the default slice/volume write intervals.

Storage Estimate¶

Estimate necessary storage for all output. Pretty rough estimate.