def compute_flight_points(self, flight_point: FlightPoint):
if flight_point.thrust_is_regulated or flight_point.thrust_rate is None:
flight_point.thrust_rate = flight_point.thrust / self.max_thrust
else:
flight_point.thrust = self.max_thrust * flight_point.thrust_rate
flight_point.sfc = self.max_sfc * (1.0 + flight_point.thrust_rate) / 2.0
def _compute_cruise_mass_ratio(self, start: FlightPoint, cruise_distance):
"""
Computes mass ratio between end and start of cruise
:param start: the initial flight point, defined for `CL`, `CD`, `mass` and`true_airspeed`
:param cruise_distance: cruise distance in meters
:return: (mass at end of cruise) / (mass at start of cruise)
"""
if self.use_max_lift_drag_ratio:
lift_drag_ratio = self.polar.optimal_cl / self.polar.cd(self.polar.optimal_cl)
else:
lift_drag_ratio = start.CL / start.CD
start.thrust = start.mass / lift_drag_ratio * g
self.propulsion.compute_flight_points(start)
range_factor = start.true_airspeed * lift_drag_ratio / g / start.sfc
return 1.0 / np.exp(cruise_distance / range_factor)
def _compute_propulsion(self, flight_point: FlightPoint):
flight_point.thrust = flight_point.drag
flight_point.thrust_is_regulated = True
self.propulsion.compute_flight_points(flight_point)
