phasicFlow/utilities/postprocessPhasicFlow

postprocessPhasicFlow Utility

This is a documentation for the postprocessPhasicFlow utility. This utility is designed to perform post-simulation processing on completed simulation data.

Table of Contents

• 1. Overview
• 2. When to Use postprocessPhasicFlow
• 3. Basic Usage
• 4. Command Line Options
  • 4.1. Available Options
  • 4.2. Examples
• 5. Configuration
  • 5.1. Important Configuration Parameters for Post-Simulation Processing
• 6. Difference Between In-Simulation and Post-Simulation Processing
• 7. File Structure
• 8. Advanced Features
• 9. Example Configuration
• 10. Troubleshooting
• 11. See Also

1. Overview

postprocessPhasicFlow is a utility for performing postprocessing analysis on completed simulation data. It allows you to extract statistical information, track specific particles, and analyze regional particle behavior without needing to re-run your simulations. This utility leverages the functionality provided by phasicFlow's PostprocessData module to analyze data stored in time folders.

2. When to Use postprocessPhasicFlow

You should use this utility when:

1. Your simulation has completed and you want to analyze the results
2. You want to try different postprocessing configurations on the same simulation data
3. You need to extract additional information that wasn't included in real-time processing
4. You want to focus on specific time periods or regions of your simulation domain

3. Basic Usage

To use the postprocessPhasicFlow utility, navigate to your simulation case directory and run:

postprocessPhasicFlow

This will read the postprocessDataDict file from your case's settings directory and perform the configured postprocessing operations on all available time folders.

4. Command Line Options

The postprocessPhasicFlow utility supports several command line options that allow you to customize its behavior:

postprocessPhasicFlow [OPTIONS]

4.1. Available Options

Option	Description
-o, --out-folder <path>	Specify the output directory path where postprocessing results will be written. Default is ./postprocessData/
-t, --time <times>	Process only specific time folders. Accepts multiple formats: - Space-separated list of times (e.g., 0.1 0.2 0.3) - Strided range with format <begin>:<stride>:<end> (e.g., 0.1:0.1:0.5) - Interval with format <begin>:<end> (e.g., 0.1:0.5)
-z, --zeroFolder	Include the zero folder (initial state) in the processing. By default, the zero folder is not processed.
-h, --help	Display help message with all available options

4.2. Examples

Process all available time folders (except zero folder):

postprocessPhasicFlow

Process only specific time steps:

postprocessPhasicFlow -t 0.1 0.2 0.5

Process a range of time steps from 0.1 to 1.0 with 0.1 increments:

postprocessPhasicFlow -t 0.1:0.1:1.0

Process all time steps including the initial state (zero folder):

postprocessPhasicFlow -z

Write output to a custom directory:

postprocessPhasicFlow -o /path/to/custom/output

5. Configuration

The postprocessPhasicFlow utility is configured through the same postprocessDataDict file used for in-simulation postprocessing. This file should be placed in the settings directory of your case.

5.1. Important Configuration Parameters for Post-Simulation Processing

When using postprocessPhasicFlow for post-simulation processing, pay special attention to these settings:

// For post-simulation, runTimeActive should be set to "no"
// This indicates that you're doing post-simulation processing
runTimeActive no;

// Specify the correct shape type used in your simulation
// This is essential for post-simulation processing
shapeType sphere; // Options: sphere, grain, etc.

The shapeType parameter is particularly crucial for post-simulation processing as it tells the utility what kind of particles were used in the simulation, allowing it to correctly interpret the stored data.

6. Difference Between In-Simulation and Post-Simulation Processing

Feature	In-Simulation Processing	Post-Simulation Processing with postprocessPhasicFlow
When it runs	During simulation execution	After simulation is complete
How to activate	Set runTimeActive yes in postprocessDataDict, set auxFunctions postprocessData in settingsDict and add library	Run the postprocessPhasicFlow utility
Data access	Direct access to simulation data in memory	Reads data from time folders
Performance impact	May slow down simulation	No impact on simulation performance
Iterations	Can only run once per simulation step	Can be run multiple times with different settings

7. File Structure

The results of the postprocessing will be written to files in your case directory (by default, under postprocessData folder), with timestamps and naming that matches your configured components and operations. These files can then be used for further analysis or visualization.

8. Advanced Features

postprocessPhasicFlow supports all the features of the PostprocessData module, including:

• Different processing methods (arithmetic, uniformDistribution, GaussianDistribution)
• Various region types (sphere, multipleSpheres, line, centerPoints)
• Multiple operation types (average, sum, avMassVelocity)
• Special field functions (component, abs, square, magnitude, etc.)
• Particle filtering with includeMask

but it disables/ignores the effect of all timeControl settings in postprocess components.

For detailed information about these features, refer to the PostprocessData module documentation.

9. Example Configuration

Here's a simple example of a postprocessDataDict file configured for post-simulation processing:

/* -------------------------------*- C++ -*--------------------------------- *\ 
|  phasicFlow File                                                            | 
|  copyright: www.cemf.ir                                                     | 
\* ------------------------------------------------------------------------- */  
objectName   postprocessDataDict;
objectType   dictionary;;
fileFormat   ASCII;
/*---------------------------------------------------------------------------*/

// Set to "no" for post-simulation processing
runTimeActive no;

// Required for post-simulation processing - specify the shape type used in the simulation
shapeType sphere;

// Default time control settings
defaultTimeControl
{
    timeControl         timeStep;
    startTime           0;
    endTime             1000;
    executionInterval   20;
}

// List of postprocessing components
components
(
    // Track specific particles by ID
    particleTracker
    {
        processMethod    particleProbe;
        processRegion    centerPoints;
        selector         id;
        field            velocity;
        ids              (10 42 87);
        timeControl      default;
    }
    
    // Analyze particle behavior in a spherical region
    centerRegionAnalysis
    {
        processMethod    arithmetic;
        processRegion    sphere;
        
        sphereInfo
        {
            radius  0.05;
            center  (0 0 0.1);
        }
        
        timeControl default;
        
        operations
        (
            velocityMagnitude
            {
                function        average;
                field           mag(velocity);
                threshold       5;
                divideByVolume  no;
                fluctuation2    yes;
            }
            
            particleDensity
            {
                function        sum;
                field           mass;
                divideByVolume  yes;
            }
        );
    }
);

10. Troubleshooting

If you encounter issues with the postprocessPhasicFlow utility, check the following:

1. Make sure your postprocessDataDict file specifies the correct shapeType
2. Verify that the time folders contain all the required field data
3. Check that field names referenced in your configuration exist in the simulation data
4. Ensure that the simulation case structure is intact and not modified

11. See Also

• PostprocessData module documentation
• phasicFlow simulation tutorials