flow-state-calculator 0.1.0

Lightweight utility for constructing compressible flow states and reference conditions

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 using the "Cite this repository" button on GitHub, or:

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

License

BSD-3-Clause. See LICENSE for details.