Flashing Nozzle Design

Sizing and analysis tools for flashing (two-phase) nozzles and turbine expanders in partial-evaporation Rankine cycle (ORC) power systems.

The package covers the calculations needed to size a preliminary ORC system around a flashing nozzle or turbine: thermodynamic cycle evaluation, choked (sonic) flow conditions, droplet size and slip velocity estimation at the nozzle throat, and rig sizing across candidate working fluids.

Project layout

flashing_nozzle_design/
├── src/
│   └── flashing_nozzle_design/   # installable package (import as `import flashing_nozzle_design`)
│       ├── __init__.py
│       ├── functions.py          # cycle, choking, droplet-size and rig sizing calculations
│       └── graphics.py           # matplotlib styling and plotting helpers
├── cases/                        # runnable scripts + input configuration files, one folder per case
└── pyproject.toml                # Poetry project and dependency configuration

Installation

1. Install Poetry

This project uses Poetry for dependency management and packaging. If it is not already installed, install it with the official installer:

Linux / macOS:

curl -sSL https://install.python-poetry.org | python3 -

Windows (PowerShell):

(Invoke-WebRequest -Uri https://install.python-poetry.org -UseBasicParsing).Content | py -

After installation, restart your terminal and verify it worked:

poetry --version

See the official installation guide if you encounter problems.

2. Clone the repository

git clone https://github.com/turbo-sim/flashing_nozzle_design.git
cd flashing_nozzle_design

3. Install the project and its dependencies

poetry install

This creates an isolated virtual environment, installs all runtime and development dependencies declared in pyproject.toml, and installs the project itself in editable mode so that import flashing_nozzle_design works everywhere.

4. Verify the installation was successful

The quickest way to check everything is working is to run the minimal example in cases/demo. Run the case through Poetry to make sure it uses the project's virtual environment:

poetry run python cases/demo/run_flashing_nozzle_sizing.py

If the installation succeeded, this will:

• print a report of the thermodynamic states and sizing results
• opens a plot window with the fluid's temperature-entropy (T-s) diagram