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Examples

PyThrust includes runnable examples that show the main workflows: solving against catalog data, calibrating losses from measurements, and using OpenMDAO for propulsion co-design.

Run examples from the repository root so relative data/ and docs/images/ paths resolve correctly.

PYTHONPATH=. python examples/<example_name>.py

Requirements

Example Extra dependencies
calibrate_from_datasheet.py Core PyThrust dependencies
select_motor.py openmdao
optimize_and_plot_propulsion.py openmdao, matplotlib

Install the full example environment:

pip install -e .[plot,openmdao]

Datasheet Calibration

Script:

PYTHONPATH=. python examples/calibrate_from_datasheet.py

This example identifies the lumped system resistance for a motor, propeller, battery, ESC, and wiring setup.

It uses:

Input Value or source
Motor Datasheet Kv, resistance, no-load current, and current limit
Propeller APC_13x6.5E from data/propellers/apc_202602
Battery 4S nominal voltage, 14.8 V
Test table RPM, thrust in grams, and battery current in amps

The output reports:

Metric Meaning
System resistance Fitted SystemSpec.resistance_ohm
Thrust RMSE Propeller-model thrust error against measured thrust
Current RMSE Battery-current prediction error
Thrust R2 Fit quality for the aerodynamic thrust prediction
Per-point table Predicted vs measured thrust/current for each RPM row

See Motor Calibration for the calibration model and equations.

Calibration results

Motor Selection

Script:

PYTHONPATH=. python examples/select_motor.py

This example combines theoretical co-design with real motor database lookup.

Workflow:

  1. Load APC_13x6.5E propeller data.
  2. Use OpenMDAO to find an efficient theoretical motor/propeller/throttle combination for hover.
  3. Load the brushless motor database from data/motors.
  4. Search real motors near the optimized Kv and current requirement.
  5. Print the top candidates sorted by winding resistance and weight.

The optimization target is a hover thrust of 4.903 N, approximately 500 gf.

Typical output includes:

Output Meaning
Target Kv Ideal speed constant from the theoretical optimization
Target diameter Optimized propeller diameter
Target hover current Current at the optimized hover point
Minimum hover power Battery power objective value
Top motor matches Closest catalog motors with Kv, resistance, weight, and current limit

See Component Databases for motor catalog format and query helpers.

Propulsion Optimization and Plotting

Script:

PYTHONPATH=. python examples/optimize_and_plot_propulsion.py

This example demonstrates OpenMDAO-based propulsion co-design and a parametric Kv sweep.

It performs three stages:

  1. Run the baseline propulsion model.
  2. Optimize motor Kv, propeller diameter, and throttle for a fixed hover thrust.
  3. Sweep Kv and re-optimize diameter/throttle at each point.

The generated plot is saved to:

docs/images/optimize_and_plot_results.png

The plot shows:

Panel Shows
Power and propeller size vs motor Kv Hover battery power and optimized propeller diameter
Throttle and RPM vs motor Kv Optimized throttle setting and shaft speed

Propulsion co-design optimization

See Propulsion Solver for the operating-point solver used inside the OpenMDAO component.