Zonal Analysis

Introduction

This analysis feature allows the user to define interrogation volumes by specifying the number of zones in the x, y, and z directions. The solver will then calculate the aggregate data for each zone and report it at each statistic time step. Examples of uses include:

• Mean property value (e.g., scalar, velocity magnitude, energy dissipation rate)

• Standard deviation of a given property

• Number of particles

• Mean particle size

A tutorial on using the Zonal Analysis Tool is available.

Property Grid

Analysis Type

Particle Size Histogram

Each of the defined volumes in the analysis will the number of particles categorized into the user defined number of bins. There are five features to select for this option:

Nx

User-defined number of zones in the X direction

Ny

User-defined number of zones in the Y direction

Nz

User-defined number of zones in the Z direction

Histogram Maximum Value

This is the maximum value of the histogram bins. Any particle larger than this value will be included in this bin.

Data Source Particle Name

User-selected particle source. Many times, there will only be one available selection because there is only one defined particle source, but there are times where there may be more (e.g., bubbles and particles)

Custom

The property being analyzed is defined by the user via a User Defined Function (UDF)

Nx

User-defined number of zones in the X direction

Ny

User-defined number of zones in the Y direction

Nz

User-defined number of zones in the Z direction

Components

Single Value

This option should be used when a single value is expected for each volume (e.g., count, mean)

Array Values

This value is used when multiple values are expected for each volume (i.e., Histogram)

Data Source

Fluid

This will allow fluid specific options available for analysis.

Particle

Data Source Particle Name

User-selected particle source. Many times, there will only be one available selection because there is only one defined particle source, but there are times where there may be more (e.g., bubbles and particles)

Reduction

Maximum

The maximum property value in the analysis zone

Minimum

The maximum property value in the analysis zone

Sum

The sum of the property values in the analysis zone

Mean

The mean property value in the analysis zone

Standard Deviation

The standard deviation of the property value in the analysis zone

RSD %

Property Standard Deviation / Mean

Data Type

Floating Point

Single precision floating point number

Integer

32-bit integer

Note

The integer option is a better choice for accuracy where high counts are expected.

Zonal Analysis UDF

user-defined units | This UDF defines the local value that will be reduced as part of the zonal analysis reduction. When the Component Type is Single Value, the UDF must define one floating-point output variable named value. When the component Type is Array, the UDF must define both an output integer variable named bin and an output floating-point variable named value. The bin variable defines which element of the array to populate with the data defined by the output value.

This feature is useful for defining local histograms. The units on the output variable depend on the UDF expression. The bin variable is unitless. This can be either a voxel-based or a particle-based local UDF, depending on the Data Source.

Download Sample File: Static Body Variable