Output Configuration

3.5. Output Configuration#

Outputs control what data Flow360 writes during and after a simulation. You can export flow field data on volumes, surfaces, slices, isosurfaces, and at probe points—each with configurable fields and save frequency. Additionally, you can configure force and moment outputs, including total forces on specific models and custom force distributions along arbitrary directions. Results are saved in ParaView (.vtu/.vtp), Tecplot (.szplt), or CSV formats.

Important

Outputs must be configured before running the simulation. Data that was not requested in the output configuration cannot be retrieved after the simulation completes. You would need to re-run the case with the desired outputs enabled.

Available Outputs#

The table below lists all available output types. It also contains links to the documentation of each type for both the GUI and the Python API interfaces. The File column shows the path to the file that contains the data produced by each output for custom post-processing.

Table 3.5.1 Available Output Types#

Output Type

Data

Availability

File

Volume Output

Flow field data throughout the computational volume

GUI, API

volumes.tar.gz → volume

Time-averaging Volume Output

Time-averaged flow field data throughout the volume

GUI, API

volumes.tar.gz → volume_time_avg

Surface Output

Flow field data on geometry or volume mesh boundaries

GUI, API

surfaces.tar.gz → surface_<boundary_name>

Time-averaging Surface Output

Time-averaged flow field data on surfaces

GUI, API

surfaces.tar.gz → surface_<boundary_name>_time_avg

Slice Output

Flow field data on user-defined slice planes

GUI, API

slices.tar.gz → slice_<slice_name>

Time-averaging Slice Output

Time-averaged flow field data on slice planes

GUI, API

slices.tar.gz → slice_<slice_name>_time_avg

Probe Output

Flow field data monitoring during simulation

GUI, API

monitor_<output_name>_v2.csv

Time-averaging Probe Output

Time-averaged monitoring data

GUI, API

monitor_<output_name>_v2.csv

Surface Probe Output

Flow field data at specific points projected onto surfaces

GUI, API

monitor_<output_name>_v2.csv

Time-average Surface Probe Output

Time-averaged data at specific surface points

API

monitor_<output_name>_v2.csv

Surface Slice Output

Flow field data on slices of surfaces

API

surfaces.tar.gz → surface_slice_<slice_name>

Isosurface Output

Flow field data on surfaces of constant variable value

GUI, API

isosurfaces.tar.gz → isosurface_<isosurface_name>

Time-averaging Isosurface Output

Time-averaged flow field data on isosurfaces

GUI, API

isosurfaces.tar.gz → isosurface_<isosurface_name>_time_avg

Surface Integral Output

Surface integral data

GUI, API

monitor_<output_name>_v2.csv

Aeroacoustic Output

Data for aeroacoustic analysis at observer positions

GUI, API

total_acoustics_v3.csv

Force Output

Force and moment coefficient outputs with optional statistics

GUI, API

force_output_<output_name>_v2.csv + force_output_<output_name>_moving_statistic_v2.csv

Force Distribution Output

Custom force and moment distribution along a specified direction

GUI, API

<output_name>_forceDistribution.csv

Time-averaging Force Distribution Output

Time-averaged custom force and moment distribution

API

Time-averaging<output_name>_forceDistribution.csv

Streamline Output

Streamline visualization data

GUI, API

N/A

Time-averaging Streamline Output

Time-averaged streamline visualization data

GUI, API

N/A

Output Fields#

Note

The fields listed below are the default output fields provided by Flow360. All values are non-dimensional unless otherwise noted. See Non-Dimensional Outputs for dimensionalization formulas.

Important

Custom and Dimensional Outputs: Use User Variables to define custom output expressions or to output existing fields in dimensional units (e.g., velocity_m_per_s, pressure_pa, wall_shear_stress_magnitude_pa). See Units & Expressions for details.

Universal Fields#

Available for all output types (Volume, Surface, Slice, Isosurface, Probe):

Name

Description

Cp

Coefficient of pressure Eq.(3.8.10)

Cpt

Coefficient of total pressure Eq.(3.8.12)

gradW

Gradient of primitive solution

kOmega

k and omega when using the kOmegaSST model

Mach

Mach number

mut

Turbulent viscosity

mutRatio

Ratio between turbulent viscosity and freestream dynamic viscosity \(\mu_t/\mu_\infty\)

nuHat

Spalart-Allmaras variable, nuHat

primitiveVars

Primitive solution: rho, u, v, w, p (density, 3 velocities and pressure)

qcriterion

Q criterion

residualNavierStokes

5 components of the N-S residual

residualTransition

Residual for the transition model

residualTurbulence

Residual for the turbulence model

s

Entropy

solutionNavierStokes

Solution for the N-S equation in conservative form

solutionTransition

Solution for the transition model

solutionTurbulence

Solution for the turbulence model

T

Temperature

velocity

Velocity vector

velocity_magnitude

Velocity magnitude

pressure

Pressure

vorticity

Vorticity vector

vorticityMagnitude

Vorticity magnitude

wallDistance

Wall distance

numericalDissipationFactor

Sensor showing where the numericalDissipationFactor has been increased

residualHeatSolver

Residual for the heat equation solver

VelocityRelative

Velocity vector from which velocity of a non-inertial frame is subtracted. Equals 0 on any no-slip walls within rotational blocks.

lowMachPreconditionerSensor

Low-Mach preconditioner factor

Surface-Specific Fields#

Available only for Surface Output and Surface Probe Output:

Name

Description

Cf

Skin friction coefficient magnitude

CfVec

Skin friction coefficient vector Eq.(3.8.8)

yPlus

Non-dimensional wall distance (y⁺)

nodeForcesPerUnitArea

Total force per unit area (pressure + friction)

nodeNormals

Wall normal direction

heatFlux

Heat flux

heatTransferCoefficientStaticTemperature

Heat transfer coefficient (static T reference)

heatTransferCoefficientTotalTemperature

Heat transfer coefficient (total T reference)

wallFunctionMetric

Wall model quality indicator (beta)

wall_shear_stress_magnitude

Wall shear stress magnitude

Volume and Slice-Specific Fields#

Available only for Volume Output and Slice Output:

Name

Description

betMetrics

BET disk metrics: VelocityRelative, AlphaRadians, CfAxial, CfCircumferential, TipLossFactor, etc. (with overlap)

betMetricsPerDisk

Same as betMetrics but each BETdisk has its own output (no overlap)

linearResidualNavierStokes

Linear residual of Navier-Stokes solver

linearResidualTurbulence

Linear residual of turbulence solver

linearResidualTransition

Linear residual of transition solver

SpalartAllmaras_hybridModel

Hybrid RANS-LES output for Spalart-Allmaras solver (supports both DDES and ZDES)

kOmegaSST_hybridModel

Hybrid RANS-LES output for kOmegaSST solver (supports both DDES and ZDES)

localCFL

Local CFL number

Hybrid RANS-LES Model Outputs#

The SpalartAllmaras_hybridModel and kOmegaSST_hybridModel output fields provide diagnostic variables for hybrid RANS-LES simulations (DDES and ZDES). These fields are available for Volume Output and Slice Output only.

Important

Requirements:

  • SpalartAllmaras_hybridModel can only be specified when using the Spalart-Allmaras turbulence model with hybrid RANS-LES enabled (DDES or ZDES).

  • kOmegaSST_hybridModel can only be specified when using the kOmegaSST turbulence model with hybrid RANS-LES enabled (DDES or ZDES).

  • Hybrid models require unsteady simulations—they are not available for steady-state cases.

The specific variables included in each hybrid model output depend on the shielding function used:

DDES Variables#

When shielding_function="DDES", the hybrid model output includes five variables:

  1. ``f_d`` — The shielding function that delineates RANS and LES regions. When f_d = 0, RANS is fully applied; when f_d = 1, LES is used. Intermediate values represent a smooth transition between regimes.

  2. ``r_d`` — A modified ratio of the modeled length scale to the wall distance, from which f_d is derived.

  3. ``DDES_lengthRANS`` — The wall distance from the computational cell to the nearest solid boundary.

  4. ``DDES_lengthScale`` — The characteristic DES length scale: \(\tilde{d} \equiv d - f_d \max(0, d - C_{DES}*\Delta)\)

  5. ``DDES_lengthLES`` — The characteristic LES length scale: \(C_{DES}*\Delta\)

Among these variables, f_d is the most significant for identifying and visualizing regions dominated by RANS vs. LES behavior.

ZDES Variables#

When shielding_function="ZDES", the hybrid model output includes four variables:

  1. ``ZDES_fp`` — The enhanced shielding function that determines whether RANS or LES is used. When ZDES_fp = 0, RANS is active; when ZDES_fp = 1, LES is active. This function is computed from ZDES_fd, ZDES_fR, and ZDES_fp2.

  2. ``ZDES_fd`` — Original DDES shielding function used in computing ZDES_fp.

  3. ``ZDES_fR`` — Component that disables or inhibits the secondary shielding function in regions where vorticity magnitude increases away from walls (designed to disable the secondary shielding where a shear layer is detected above a wall). Used in computing ZDES_fp.

  4. ``ZDES_fp2`` — Causes the model to revert to RANS mode in the outer portion of boundary layers. Used in computing ZDES_fp.

See also

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