"""Classes for acceleration/deceleration segments."""
# This file is part of FAST-OAD : A framework for rapid Overall Aircraft Design
# Copyright (C) 2024 ONERA & ISAE-SUPAERO
# FAST is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from dataclasses import dataclass
from typing import List, Tuple
from fastoad.model_base import FlightPoint
from fastoad.models.performances.mission.exceptions import FastFlightSegmentIncompleteFlightPoint
from fastoad.models.performances.mission.segments.base import (
RegisterSegment,
)
from fastoad.models.performances.mission.segments.time_step_base import (
AbstractLiftFromWeightSegment,
AbstractManualThrustSegment,
)
[docs]@RegisterSegment("speed_change")
@dataclass
class SpeedChangeSegment(AbstractManualThrustSegment, AbstractLiftFromWeightSegment):
"""
Computes a flight path segment where speed is modified with no change in altitude.
The target must define a speed value among true_airspeed, equivalent_airspeed
and mach.
"""
[docs] def get_distance_to_target(
self, flight_points: List[FlightPoint], target: FlightPoint
) -> float:
if target.true_airspeed is not None:
return target.true_airspeed - flight_points[-1].true_airspeed
if target.equivalent_airspeed is not None:
return target.equivalent_airspeed - flight_points[-1].equivalent_airspeed
if target.mach is not None:
return target.mach - flight_points[-1].mach
raise FastFlightSegmentIncompleteFlightPoint(
"No valid target definition for altitude change."
)
[docs] def get_gamma_and_acceleration(self, flight_point: FlightPoint) -> Tuple[float, float]:
acceleration = (flight_point.thrust - flight_point.drag) / flight_point.mass
return 0.0, acceleration