GitHub Repository: junzis/openap
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OpenAP: Open Aircraft Performance Model and Toolkit

This repository contains the OpenAP model data and Python packages for aircraft performance and emission calculations.

🕮 User Guide

The OpenAP handbook is available at openap.dev.

Installation

Install the latest stable release from PyPI:

pip install --upgrade openap

Install the development branch from GitHub (may not be stable):

pip install --upgrade git+https://github.com/junzis/openap

Content

Model Data

Data in this repository includes:

Aircraft data: Collected from open literature.
Engine data: Primarily from the ICAO emission data-bank, including fuel flow and emissions.
Drag polar model data: Exclusively derived from open data (reference).
Fuel model data: Polynomial models derived from the acropole model by @JarryGabriel.
Kinematic data: The kinematic model describes speed, altitude, and vertical rate (reference).
Navigation data: Airport and waypoints obtained from X-Plane.

Python Packages

The OpenAP Python library includes the following packages:

prop: Module for accessing aircraft and engine properties.
aero: Module for common aeronautical conversions.
nav: Module for accessing navigation information.
thrust: Module provides Thrust() class for computing aircraft thrust.
drag: Module provides Drag() class for computing aircraft drag.
fuel: Module provides FuelFlow() class for computing fuel consumption.
emission: Module provides Emission() class for computing aircraft emissions.
kinematic: Module provides WRAP() class for accessing kinematic performance data.
phase: Module provides FlightPhase() class for determining flight phases.
gen: Module provides FlightGenerator() class for trajectory generation.

Examples:

import openap

openap.prop.aircraft("A320")
fuelflow = openap.FuelFlow("A320")
fuelflow.enroute(mass, tas, alt) # -> kg/s

The input parameters can be scalar, list, or ndarray. Most of the OpenAP methods' parameters are in aeronautical units, such as knots, feet, feet/min. The mass is always in SI units, i.e., kilograms.

Add-ons

The OpenAP library can also be used to interact with BADA performance models if you have access to the BADA data from EUROCONTROL. You can use the following code:

from openap.addon import bada4

fuelflow = bada4.FuelFlow()

The methods and attributes of openap.addon.bada4.FuelFlow() are the same as those of openap.FuelFlow().

Symbolic Implementation for CasADi

The OpenAP model can also be used with the CasADi library for symbolic computations. The symbolic model is available in the openap.casadi package. For example, you can use the following code to create a symbolic model for fuel flow:

from openap.casadi import FuelFlow

fuelflow = FuelFlow()

All the methods of openap.casadi.FuelFlow() are the same as those of openap.FuelFlow(), and they are now symbolic functions that can be used to compute fuel flow for given flight conditions in CasADi DM, SX, or MX types.

How did we implement this? When the casadi module is initiated, a metaclass is used to replace the sci function from numpy, which overrides all the numpy functions with casadi functions. For more details, check the openap/casadi/__init__.py code.

Citing OpenAP

@article{sun2020openap,
  title={OpenAP: An open-source aircraft performance model for air transportation studies and simulations},
  author={Sun, Junzi and Hoekstra, Jacco M and Ellerbroek, Joost},
  journal={Aerospace},
  volume={7},
  number={8},
  pages={104},
  year={2020},
  publisher={Multidisciplinary Digital Publishing Institute}
}