flow-state-calculator 0.4.0

Lightweight utility for computing flow states

flow_state

Compressible flow state calculations for Python.

Install

pip install flow-state-calculator

Quick Start

from flow_state import solve

# From Mach and altitude
state = solve(mach=2.0, altitude=10000)

# From Mach and stagnation conditions (wind tunnel)
state = solve(mach=6, pres_stag=(140, "psi"), temp_stag=420)

# From Mach and target unit Reynolds number
state = solve(mach=5.3, re1=12.8e6)

# Access results
print(state)  # Full summary
print(state.pres, state.temp, state.re1)

Features

• Smart solver: Automatically selects the right equations based on your inputs
• Unit support: Use SI or provide tuples like (30000, "ft"), (140, "psi")
• Atmosphere models: US Standard Atmosphere 1976 and CIRA-86
• Gas models: Perfect gas (air, nitrogen, custom)
• Transport: Sutherland viscosity law
• Output: JSON, TOML, or legacy .dat format

CLI

# Create a config template
flow-state init

# Edit flow_config.toml, then solve
flow-state solve

Atmosphere Models

from flow_state import solve, atmosphere

# Default: US Standard Atmosphere 1976
state = solve(mach=2, altitude=10000)

# CIRA-86 with latitude and month
state = solve(mach=2, altitude=10000, atm=atmosphere.CIRA86(latitude=70, month=1))

Documentation

Full documentation: https://uahypersonics.github.io/flow_state

Citation

If you use flow_state in your research, please cite it:

@software{flow_state,
  author = {Hader, Christoph},
  title = {flow\_state: Compressible Flow State Calculations},
  url = {https://github.com/uahypersonics/flow_state},
  year = {2026}
}

Code Style

This project follows established Python community conventions so that contributors can focus on the physics rather than inventing formatting rules.

Convention	What it covers	Reference
PEP 8	Code formatting, naming, whitespace	Python standard style guide
PEP 257	Docstring structure (triple-quoted, imperative mood)	Python standard docstring conventions
numpydoc	Docstring sections (Parameters, Returns, Attributes)	NumPy/SciPy docstring standard — the norm for scientific Python
Ruff	Automated linting and formatting	Enforces PEP 8 compliance automatically
typing / TYPE_CHECKING	Type hints for IDE support and static analysis	Python standard library

Releasing

This project uses Semantic Versioning (vMAJOR.MINOR.PATCH):

• MAJOR (v1.0.0, v2.0.0): Breaking API changes
• MINOR (v0.3.0, v0.4.0): New features, backward-compatible
• PATCH (v0.3.1, v0.3.2): Bug fixes, minor corrections

To publish a new version to PyPI:

1. Update the version in src/flow_state/_version.py
2. Regenerate the API architecture diagram:

   pydeps src/flow_state --noshow --max-bacon=4 --cluster -o docs/assets/architecture.svg
   

3. Commit and push to main
4. Tag and push:

   git tag vMAJOR.MINOR.PATCH
   git push origin vMAJOR.MINOR.PATCH
   

The GitHub Actions workflow will automatically build and publish to PyPI via Trusted Publishing.

Contributors

chader2811 💻 📖 🎨 🤔 🚧 🔣 ⚠️ 💡 🚇

Contributions are welcome: code, documentation, verification data, and bug reports. See the contribution types recognized by this project.

License

BSD-3-Clause. See LICENSE for details.