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.

../../_images/output-volumes.png

Output Panel

General

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

Tip

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

Write Time Interval

Interval at which the volume writes will occur. This can be a System UDF.

Start Time

s | 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

Stop time of volume writes.

End of simulation

Custom stop time

Output

Fluid Properties

▢ Velocity Magnitude [m/s]

▢ Velocity Vector [m/s]

▢ Time-Averaged Velocity Vector [m/s]

▢ Pressure [Pa]

▢ Density [kg/m^3]

▢ Fluid Viscosity [m^2/5]

▢ Volume Fraction [-]


Fluid Energy Cascade

▢ Total Kinetic Energy [J/kg]

▢ Time-Averaged Turbulent Kinetic Energy [J/kg]

▢ Energy Dissipation Rate [W/kg]

▢ Time-Averaged Energy Dissipation Rate [W/kg]


Fluid Kinematics

▢ Resolved Shear Stress [Pa]

▢ Time-Averaged Effective Shear Stress [Pa]

▢ Resolved Strain Rate [1/s]

▢ Resolved Strain Rate Tensor [1/s]

▢ Vorticity Magnitude [1/s]

▢ Vorticity Vector [1/s]


Mixing Properties

▢ Sub-Grid Turbulent Viscosity [m^2/s]

▢ Micromixing Timescale [s]

▢ Kolmogorov Length Scale [m]


Thermal Properties

▢ Temperature [K]


Custom Variables

▢ Mean Age [s]

▢ Porosity [-]


Scalar Fields

▢ Concentration [mol/L]

▢ Volume Fraction [-]

▢ Concentration [g/L]

▢ Diffusion Coefficient [m^2/s]