aerosandbox.library.propulsion_propeller
========================================

.. py:module:: aerosandbox.library.propulsion_propeller


Functions
---------

.. autoapisummary::

   aerosandbox.library.propulsion_propeller.propeller_shaft_power_from_thrust
   aerosandbox.library.propulsion_propeller.mass_hpa_propeller
   aerosandbox.library.propulsion_propeller.mass_gearbox


Module Contents
---------------

.. py:function:: propeller_shaft_power_from_thrust(thrust_force, area_propulsive, airspeed, rho, propeller_coefficient_of_performance=0.8)

   Using dynamic disc actuator theory, gives the shaft power required to generate
   a certain amount of thrust.

   Source: https://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node86.html

   :param thrust_force: Thrust force [N]
   :param area_propulsive: Total disc area of all propulsive surfaces [m^2]
   :param airspeed: Airspeed [m/s]
   :param rho: Air density [kg/m^3]
   :param propeller_coefficient_of_performance: propeller coeff. of performance (due to viscous losses) [unitless]
   :return: Shaft power [W]


.. py:function:: mass_hpa_propeller(diameter, max_power, include_variable_pitch_mechanism=False)

   Returns the estimated mass of a propeller assembly for low-disc-loading applications (human powered airplane, paramotor, etc.)

   :param diameter: diameter of the propeller [m]
   :param max_power: maximum power of the propeller [W]
   :param include_variable_pitch_mechanism: boolean, does this propeller have a variable pitch mechanism?
   :return: estimated weight [kg]


.. py:function:: mass_gearbox(power, rpm_in, rpm_out)

   Estimates the mass of a gearbox.

   Based on data from NASA/TM-2009-215680, available here:
       https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090042817.pdf

   R^2 = 0.92 to the data.

   To quote this document:
       "The correlation was developed based on actual weight
       data from over fifty rotorcrafts, tiltrotors, and turboprop
       aircraft."

   Data fits in the NASA document were thrown out and refitted to extrapolate more sensibly; see:
       C:\Projects\GitHub\AeroSandbox\studies\GearboxMassFits
   :param power: Shaft power through the gearbox [W]
   :param rpm_in: RPM of the input to the gearbox [rpm]
   :param rpm_out: RPM of the output of the gearbox [rpm]
   :return: Estimated mass of the gearbox [kg]