Skip to content

Command Line Interface

flow_state includes a CLI for quick calculations without writing Python code.

Commands

flow-state init

Generate a template configuration file:

1
2
3
flow-state init                    # creates flow_config.toml
flow-state init -o myconfig.toml   # custom filename
flow-state init --force            # overwrite existing

flow-state solve

Compute flow state from direct options or a config file.

Direct Options

For quick one-off calculations:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
# Wind tunnel (stagnation conditions)
flow-state solve --mach 6 --pres-stag 140 --pres-stag-unit psi --temp-stag 420

# Flight conditions
flow-state solve --mach 7 --altitude 25000

# With atmosphere model
flow-state solve --mach 7 --altitude 30000 --atm ussa76

# Nitrogen gas
flow-state solve --mach 10 --pres-stag 1800 --pres-stag-unit psi --temp-stag 1000 --gas n2

Config File

For reproducible/documented conditions:

1
2
flow-state solve --config bam6qt.toml
flow-state solve -c myconfig.toml -o results.json

See Config Files for the TOML format and Examples for downloadable configs.

Options Reference

Option Short Description
--mach -m Mach number
--pres-stag Stagnation pressure (default: Pa)
--pres-stag-unit Pressure unit: Pa, psi, atm, bar
--temp-stag Stagnation temperature [K]
--altitude -a Altitude (default: m)
--altitude-unit Altitude unit: m, ft, km
--atm Atmosphere model: ussa76, cira86
--gas Gas type: air, n2
--lref Reference length [m]
--config -c Config file (TOML)
--output -o Output file (JSON)
--quiet -q Suppress summary output

Output

By default, prints a summary to stdout:

1
2
3
4
5
FlowState Summary
=================
  pres     = 6.1136e+02 Pa
  temp     = 51.22 K
  ...

Use --output to write JSON, --quiet to suppress the summary.