# This file is part of FAST-OAD_CS23 : A framework for rapid Overall Aircraft Design
# Copyright (C) 2022 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/>.
import numpy as np
import openmdao.api as om
[docs]
class OperationalInFlightCGVariation(om.ExplicitComponent):
"""
Computes the coefficient necessary to the calculation of the cg position at any point of
the operational mission.
"""
[docs]
def setup(self):
self.add_input("data:weight:aircraft_empty:CG:x", val=np.nan, units="m")
self.add_input("data:weight:aircraft_empty:mass", val=np.nan, units="kg")
self.add_input("data:mission:operational:payload:mass", val=np.nan, units="kg")
self.add_input("data:mission:operational:payload:CG:x", val=np.nan, units="m")
self.add_output(
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
units="kg*m",
)
self.add_output(
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:mass", units="kg"
)
self.declare_partials(
of="data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:mass",
wrt=["data:mission:operational:payload:mass", "data:weight:aircraft_empty:mass"],
val=1.0,
)
self.declare_partials(
of="data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
wrt=[
"data:weight:aircraft_empty:mass",
"data:weight:aircraft_empty:CG:x",
"data:mission:operational:payload:mass",
"data:mission:operational:payload:CG:x",
],
method="exact",
)
[docs]
def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
m_empty = inputs["data:weight:aircraft_empty:mass"]
x_cg_plane_aft = inputs["data:weight:aircraft_empty:CG:x"]
payload = inputs["data:mission:operational:payload:mass"]
x_cg_payload = inputs["data:mission:operational:payload:CG:x"]
equivalent_moment = m_empty * x_cg_plane_aft + payload * x_cg_payload
mass = m_empty + payload
outputs[
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment"
] = equivalent_moment
outputs["data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:mass"] = mass
[docs]
def compute_partials(self, inputs, partials, discrete_inputs=None):
partials[
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
"data:weight:aircraft_empty:mass",
] = inputs["data:weight:aircraft_empty:CG:x"]
partials[
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
"data:weight:aircraft_empty:CG:x",
] = inputs["data:weight:aircraft_empty:mass"]
partials[
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
"data:mission:operational:payload:mass",
] = inputs["data:mission:operational:payload:CG:x"]
partials[
"data:weight:aircraft:in_flight_variation:operational:fixed_mass_comp:equivalent_moment",
"data:mission:operational:payload:CG:x",
] = inputs["data:mission:operational:payload:mass"]