# [AeroSandbox](https://peterdsharpe.github.io/AeroSandbox/) :airplane:
by [Peter Sharpe](https://peterdsharpe.github.io) (<pds [at] mit [dot] edu>)
[![Downloads](https://pepy.tech/badge/aerosandbox)](https://pepy.tech/project/aerosandbox)
[![Monthly Downloads](https://pepy.tech/badge/aerosandbox/month)](https://pepy.tech/project/aerosandbox)
[![Build Status](https://github.com/peterdsharpe/AeroSandbox/workflows/Tests/badge.svg)](https://github.com/peterdsharpe/AeroSandbox/actions/workflows/run-pytest.yml)
[![PyPI](https://img.shields.io/pypi/v/aerosandbox.svg)](https://pypi.python.org/pypi/aerosandbox)
## Overview
**AeroSandbox is a Python package for design optimization of engineered systems such as aircraft.**
At its heart, AeroSandbox is an optimization suite that combines the ease-of-use of [familiar NumPy syntax](aerosandbox/numpy) with the power of [modern automatic differentiation](./tutorial/10%20-%20Miscellaneous/03%20-%20Resources%20on%20Automatic%20Differentiation.md).
This automatic differentiation dramatically improves optimization performance on large problems: **design problems with tens of thousands of decision variables solve in seconds on a laptop**.
AeroSandbox also comes with dozens of end-to-end-differentiable aerospace physics models, allowing you to **simultaneously optimize an aircraft's aerodynamics, structures, propulsion, mission trajectory, stability, and more.**
![VLM Image](media/images/vlm3_with_control_surfaces.png)
*VLM simulation of a glider, aileron deflections of +-30°. Runtime of 0.35 sec on a typical laptop (i7-8750H).*
![PANEL Image](media/images/panel1_naca4412.png)
*Panel simulation of a wing (extruded NACA2412, α=15°, AR=4). Note the strong three-dimensionality of the flow near the tip.*
## Getting Started
### Installation
In short:
* `pip install aerosandbox[full]` for a complete install.
* `pip install aerosandbox` for a lightweight (headless) installation with minimal dependencies. All optimization, numerics, and physics models are included, but optional visualization dependencies are skipped.
For more installation details (e.g., if you're new to Python), [see here](./INSTALLATION.md).
### Tutorials, Examples, and Documentation
To get started, [check out the tutorials folder here](./tutorial/)! All tutorials are viewable in-browser, or you can open them as Jupyter notebooks by cloning this repository.
For a more detailed and theory-heavy introduction to AeroSandbox, [please see this thesis](./tutorial/sharpe-pds-sm-AeroAstro-2021-thesis.pdf).
For a yet-more-detailed developer-level description of AeroSandbox modules, [please see the developer README](aerosandbox/README.md).
You can print documentation and examples for any AeroSandbox object by using the built-in `help()` function (e.g., `help(asb.Airplane)`). AeroSandbox code is also documented *extensively* in the source and contains hundreds of unit test examples, so examining the source code can also be useful.
### Usage Details
One final point to note: as we're all sensible and civilized here, **all inputs and outputs to AeroSandbox are expressed in base SI units, or derived units thereof** (e.g, m, N, kg, m/s, J, Pa).
The only exception to this rule is when units are explicitly noted via variable name suffix. For example:
* `battery_capacity` -> Joules
* `battery_capacity_watt_hours` -> Watt-hours.
All angles are in radians, except for α and β which are in degrees due to long-standing aerospace convention. (In any case, units are marked on all function docstrings.)
If you wish to use other units, consider using `aerosandbox.tools.units` to convert easily.
## Project Details
### Contributing
Please feel free to join the development of AeroSandbox - contributions are always so welcome! If you have a change you'd like to make, the easiest way to do that is by submitting a pull request.
The text file [`CONTRIBUTING.md`](./CONTRIBUTING.md) has more details for developers and power users.
If you've already made several additions and would like to be involved in a more long-term capacity, please message me!
Contact information can be found next to my name near the top of this README.
### Donating
If you like this software, please consider donating to support development [via PayPal](https://paypal.me/peterdsharpe)
or [GitHub Sponsors](https://github.com/sponsors/peterdsharpe/)! Proceeds will go towards more coffee for the grad students.
### Bugs
Please, please report all bugs by creating a new issue at [https://github.com/peterdsharpe/AeroSandbox/issues](https://github.com/peterdsharpe/AeroSandbox/issues)!
### Versioning
AeroSandbox loosely uses [semantic versioning](https://semver.org/), which should give you an idea of whether or not you can probably expect backward-compatibility and/or new features from any given update. However, the code is a work in progress and things change rapidly - for the time being, please freeze your version of AeroSandbox for any serious deployments. Commercial users: I'm more than happy to discuss consulting work for active AeroSandbox support if this package proves helpful!
### Citation
If you find AeroSandbox useful in a research publication, please cite it using the following BibTeX snippet:
```bibtex
@mastersthesis{aerosandbox,
title = {AeroSandbox: A Differentiable Framework for Aircraft Design Optimization},
author = {Sharpe, Peter D.},
school = {Massachusetts Institute of Technology},
year = {2021}
}
```
### License
[MIT License, terms here](LICENSE.txt). Basically: use AeroSandbox for anything you want; no warranty express or implied.
## Stargazers over time
[![Stargazers over time](https://starchart.cc/peterdsharpe/AeroSandbox.svg)](https://starchart.cc/peterdsharpe/AeroSandbox)