fastoad.models.performances.breguet.breguet module

Implementation of the Breguet Formula.

class fastoad.models.performances.breguet.breguet.Breguet(propulsion: fastoad.models.propulsion.propulsion.IPropulsion, lift_drag_ratio: float, cruise_mach: float, cruise_altitude: float, climb_mass_ratio: float = 0.97, descent_mass_ratio: float = 0.98, reserve_mass_ratio: float = 0.06, climb_descent_distance: float = 500000.0)[source]

Bases: object

Class for computing consumed fuel for a simple flight.

Fuel consumption during cruise is computing with Breguet formula. Climb and descent phases are roughly estimated using provided mass ratios.

Parameters

  • propulsion – the propulsion model for computation of consumption

  • lift_drag_ratio – the lift/drag ratio that will be used during cruise

  • cruise_mach – Mach number in cruise

  • cruise_altitude – in meters. Altitude in cruise

  • climb_mass_ratio – (mass at end of climb ) / (mass at start of climb)

  • descent_mass_ratio – (mass at end of descent ) / (mass at start of descent)

  • reserve_mass_ratio – (mass of reserve fuel) / ZFW

  • climb_descent_distance – in meters. Sum of ground distances during climb and descent

compute(takeoff_weight, flight_range)[source]

Computes the flight consumption.

Results are provided as class attributes.

Parameters

  • takeoff_weight –

  • flight_range –

compute_cruise_mass_ratio(initial_cruise_mass, cruise_distance)[source]
Parameters

  • initial_cruise_mass –

  • cruise_distance –

Returns

(mass at end of cruise) / (mass at start of cruise)