OpenFAST-DLC-Runner

A Python-based automation script for running sequential OpenFAST Design Load Case (DLC) simulations by updating input files, executing OpenFAST, and organizing simulation outputs.

This tool was developed for project-specific DLC studies where a large number of wind seeds and wind speeds must be simulated without manual intervention.

---

Overview

Running multiple OpenFAST simulations for a single DLC often requires repetitive manual steps such as updating wind files, modifying HydroDyn inputs, executing OpenFAST, and organizing output files.

OpenFAST-DLC-Runner automates this workflow by iterating over a set of wind files, updating the corresponding OpenFAST input files, launching simulations via a batch file, and systematically renaming and storing outputs for post-processing.

The script is designed as a project-level automation utility, not as a general-purpose OpenFAST framework.

---

Key Capabilities

• Iterates over multiple .bts wind files
• Extracts wind speed and seed information from filenames
• Automatically updates:
  • Inflow wind file references (InflowFile.dat)
  • HydroDyn input files based on wind speed
  • HydroDyn references in the .fst file
• Executes OpenFAST simulations via a Windows batch file
• Automatically handles command prompt interaction
• Organizes and renames output files by wind speed and seed
• Reduces the need for manual supervision during long DLC runs

---

Typical Use Cases

• Running many wind seeds for a single DLC
• Automating repetitive OpenFAST input updates
• Overnight or long-duration simulation campaigns
• Academic and research-based DLC studies

---

Installation

Requirements

• Windows operating system
• Python 3.x
• OpenFAST installed and accessible via batch file

Python Dependencies

Install required packages: pyautogui

pip install pyautogui

Required libraries include:

• pyautogui

• os, shutil, subprocess (standard library)

---

Usage

1. Prepare Input Files

• Place all wind files (.bts) in the Wind directory

• Place HydroDyn input files in the Wave directory

• Ensure wind file names follow a consistent naming convention (used to extract wind speed and seed)

2. Configure Script Paths

Edit the following paths in the script:

wind_directory = "../Wind"
hydrodyn_directory = "../Wave"
main_directory = "path/to/DLC_directory"

Ensure that:

• InflowFile.dat

• .fst file

• start_OpenFAST_v3-41.bat

exist in the main directory.

3. Run the Script

Execute the script from a terminal or IDE (VS Code recommended):

python project.py

VS Code is recommended for better scrollback and monitoring of long runs.

---

Output Organization

Simulation outputs are automatically:

• Moved to the Outputs/<DLC> directory corresponding to the DLC being run

• Renamed using the format that is needed

Example:

OPT-MP-V{WindSpeed}_S{Seed}.out
OPT-MP-V{WindSpeed}_S{Seed}.outb

This structure simplifies post-processing and traceability.

---

Project Structure

📂 OpenFast-DLC-Runner ├── 📁 DLC12 # Main Directory │ └── 📂 Outputs # Outputs are generated here │ └── 📂 DLC12 # Organized simulation results │ └── OpenFast-DLC-Runner.py # Main script for automation │ └── start_OpenFAST_v3-41.bat │ └── openfast related files and directories ├── 📁 Wind # Contains .bts wind files ├── 📁 Wave # Contains HydroDyn input files

⚠️ Note: The exact file names and folder arrangement may vary depending on your project setup.
Ensure that `OpenFast-DLC-Runner.py`, OpenFAST input files, and the batch file are located in the same DLC folder when running the script.

---

Limitations

• Designed for a specific turbine and directory structure

• File names and paths are project-specific

• Uses Windows batch execution and pyautogui

• Runs simulations sequentially (not parallel)

• Requires manual adaptation for other turbines or DLCs

---

Related Tools

This tool is part of a broader OpenFAST automation workflow:

• OpenFAST-DLC-Runner Automates generation and execution of individual DLC cases https://github.com/Araz-m/OpenFAST-DLC-Runner

• OpenFAST-Output-Monitor Real-time and post-processing visualization of OpenFAST outputs https://github.com/Araz-m/OpenFAST-Output-Monitor

---

User Guide / PDF Manual

A detailed PDF manual (Download the PDF manual ) is included for step-by-step instructions, particularly useful for users who are new to OpenFAST or Python scripting.

---

License

This project is licensed under the MIT License. See the LICENSE file for details.

---

Author

Developed by Araz Hamayeli Mehrabani
Flensburg University of Applied Sciences