"""
Estimation of max fuel 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
from openmdao.core.explicitcomponent import ExplicitComponent
# TODO: This belongs more to mass breakdown than geometry
[docs]class ComputeMFW(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Max fuel weight estimation """
[docs] def setup(self):
self.add_input("data:geometry:wing:area", val=np.nan, units="m**2")
self.add_input("data:geometry:wing:aspect_ratio", val=np.nan)
self.add_input("data:geometry:wing:root:thickness_ratio", val=np.nan)
self.add_input("data:geometry:wing:tip:thickness_ratio", val=np.nan)
self.add_output("data:weight:aircraft:MFW", units="kg")
[docs] def setup_partials(self):
self.declare_partials("data:weight:aircraft:MFW", "*", method="fd")
[docs] def compute(self, inputs, outputs):
wing_area = inputs["data:geometry:wing:area"]
lambda_wing = inputs["data:geometry:wing:aspect_ratio"]
el_emp = inputs["data:geometry:wing:root:thickness_ratio"]
el_ext = inputs["data:geometry:wing:tip:thickness_ratio"]
# TODO: remove hard coded value
mfw = (
224 * (wing_area ** 1.5 * lambda_wing ** (-0.4) * (0.6 * el_emp + 0.4 * el_ext)) + 1570
)
outputs["data:weight:aircraft:MFW"] = mfw