Batch Processing

RfbFoam includes a Python automation framework for performing parametric sweeps of applied potentials and inlet velocities, making it straightforward to generate polarization curves. The scripts are located in the batch_run/ directory.

Overview

The batch processing system automates:

1. Running a single flow simulation for each inlet velocity
2. Sweeping applied potentials using the converged velocity field
3. Extracting macro results (current density, overpotential, power losses) from log files
4. Optional plotting and saving of results and residuals

Configuration

The main entry point is batch_run/MainControl.py. Define the following variables:

• case_directory: Path to the OpenFOAM case directory

Parametric Sweep Definitions

Define the parameters for the parametric sweep:

Parameter	Description
potentials	List of applied potentials to sweep (e.g., [-0.77, -0.8, -0.85, -0.9])
velocity	List of inlet velocity vectors as tuples (e.g., [(0, 0, -0.005), (0, 0, -0.01)])
results_folder_name	Index of the velocity component to use for naming result folders (0=x, 1=y, 2=z)

Script Behavior Flags

Control the script's execution by setting these flags in MainControl.py:

Flag	Description
run_fluid_dynamics	Enable/disable fluid dynamics simulations
run_electrochemistry	Enable/disable electrochemistry simulations
continuation_sweep	True: continue from latest results; False: use initial conditions from 0/ folder
plot_residual	Enable/disable plotting of residuals
save_residual_plot	Save residual plots as files
plot_result	Enable/disable plotting of electrochemistry results
save_results_plot	Save result plots as image files
save_results	Save the full simulation field results (set to False to reduce storage on clusters)

OpenFOAM Setup

Ensure the controlDict file is configured as follows for proper continuation sweeps:

startFrom       latestTime;
stopAt          writeNow;

Running a Parametric Sweep

cd batch_run
python MainControl.py

The script will iterate over the specified velocities and applied potentials, running each simulation and collecting results.

Output Structure

Results are organized in a directory hierarchy based on velocity and potential:

Case_Directory/
├── Ux0.05_Uy0.00_Uz0.00/          # Folder named after velocity components
│   ├── Results.txt                  # Extracted macro results (current density,
│   │                                # overpotential, power losses, etc.)
│   ├── residual_plot_X.svg          # (if enabled) Residual plot
│   ├── result_plot_X.svg            # (if enabled) Overpotential curve plot
│   │
│   ├── Potential_0.8V/              # Sub-folder for each applied potential
│   │   ├── log.electrochemistry     # Log file for the simulation
│   │   └── postProcessing/          # (if enabled) Post-processed results
│   │
│   └── Potential_1.0V/
│       └── ...
│
└── Ux0.10_Uy0.00_Uz0.00/
    └── ...

• The main output directory is named based on the velocity vector components (x, y, z). If velocity parameter lists are left empty, the folder name uses values from the 0/ directory.
• A Results.txt file in each velocity folder contains the macro results extracted from the log files.
• Intermediate time folders (e.g., 1, 2, ...) are deleted after each simulation, preserving only the final time step.

Script Architecture

The batch processing system is organized into modules in batch_run/Functions/:

Module	Purpose
main_funct.py	Core orchestration logic
run_funct.py	OpenFOAM case execution
control_funct.py	Control and configuration management
plot_funct.py	Result visualization and plotting