"""
Estimation of flight controls weight
"""
# This file is part of FAST-OAD : A framework for rapid Overall Aircraft Design
# Copyright (C) 2021 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 FlightControlsWeight(om.ExplicitComponent):
"""
Flight controls weight estimation
Based on formulas in :cite:`supaero:2014`, mass contribution A4
"""
[docs] def setup(self):
self.add_input("data:geometry:fuselage:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:b_50", val=np.nan, units="m")
self.add_input("data:mission:sizing:cs25:sizing_load_1", val=np.nan, units="kg")
self.add_input("data:mission:sizing:cs25:sizing_load_2", val=np.nan, units="kg")
self.add_input(
"settings:weight:airframe:flight_controls:mass:k_fc", val=0.85
) # FIXME: this one should depend on a boolan electric/not-electric flight_controls
self.add_input("tuning:weight:airframe:flight_controls:mass:k", val=1.0)
self.add_input("tuning:weight:airframe:flight_controls:mass:offset", val=0.0, units="kg")
self.add_output("data:weight:airframe:flight_controls:mass", units="kg")
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
fus_length = inputs["data:geometry:fuselage:length"]
b_50 = inputs["data:geometry:wing:b_50"]
k_fc = inputs["settings:weight:airframe:flight_controls:mass:k_fc"]
k_a4 = inputs["tuning:weight:airframe:flight_controls:mass:k"]
offset_a4 = inputs["tuning:weight:airframe:flight_controls:mass:offset"]
max_nm = max(
inputs["data:mission:sizing:cs25:sizing_load_1"],
inputs["data:mission:sizing:cs25:sizing_load_2"],
)
temp_a4 = k_fc * max_nm * (fus_length ** 0.66 + b_50 ** 0.66)
outputs["data:weight:airframe:flight_controls:mass"] = k_a4 * temp_a4 + offset_a4