"""
Python module for maximum fuel weight calculation with simple approach, part of the geometry
component.
"""
# This file is part of FAST-OAD_CS23 : A framework for rapid Overall Aircraft Design
# Copyright (C) 2025 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 warnings
import numpy as np
import openmdao.api as om
import fastoad.api as oad
from ...constants import SERVICE_MFW, SUBMODEL_MFW_LEGACY
oad.RegisterSubmodel.active_models[SERVICE_MFW] = SUBMODEL_MFW_LEGACY
[docs]@oad.RegisterSubmodel(SERVICE_MFW, SUBMODEL_MFW_LEGACY)
class ComputeMFWSimple(om.ExplicitComponent):
"""Max fuel weight estimation based on RAYMER table 10.5 p269."""
# pylint: disable=missing-function-docstring
# Overriding OpenMDAO setup
[docs] def setup(self):
self.add_input("data:propulsion:fuel_type", val=np.nan)
self.add_input("data:geometry:wing:area", val=np.nan, units="m**2")
self.add_input("data:geometry:wing:root:chord", val=np.nan, units="m")
self.add_input("data:geometry:wing:tip:chord", val=np.nan, units="m")
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")
self.declare_partials(
"*",
[
"data:geometry:wing:area",
"data:geometry:wing:root:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:root:thickness_ratio",
"data:geometry:wing:tip:thickness_ratio",
],
method="exact",
)
self.declare_partials("*", "data:propulsion:fuel_type", method="fd")
# pylint: disable=missing-function-docstring, unused-argument
# Overriding OpenMDAO compute, not all arguments are used
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
fuel_type = inputs["data:propulsion:fuel_type"]
wing_area = inputs["data:geometry:wing:area"]
root_chord = inputs["data:geometry:wing:root:chord"]
tip_chord = inputs["data:geometry:wing:tip:chord"]
root_thickness_ratio = inputs["data:geometry:wing:root:thickness_ratio"]
tip_thickness_ratio = inputs["data:geometry:wing:tip:thickness_ratio"]
if fuel_type == 1.0:
m_vol_fuel = 718.9 # gasoline volume-mass [kg/m**3], cold worst case, Avgas
elif fuel_type == 2.0:
m_vol_fuel = 860.0 # Diesel volume-mass [kg/m**3], cold worst case
elif fuel_type == 3.0:
m_vol_fuel = 804.0 # Jet-A1 volume mass [kg/m**3], cold worst case
else:
m_vol_fuel = 718.9
warnings.warn("Fuel type {} does not exist, replaced by type 1!".format(fuel_type))
# Tanks are between 1st (30% MAC) and 3rd (60% MAC) longeron: 30% of the wing
ave_thickness = (
0.7 * (root_chord * root_thickness_ratio + tip_chord * tip_thickness_ratio) / 2.0
)
mfv = 0.3 * wing_area * ave_thickness
mfw = mfv * m_vol_fuel
outputs["data:weight:aircraft:MFW"] = mfw
# pylint: disable=missing-function-docstring, unused-argument
# Overriding OpenMDAO compute_partials, not all arguments are used
[docs] def compute_partials(self, inputs, partials, discrete_inputs=None):
fuel_type = inputs["data:propulsion:fuel_type"]
wing_area = inputs["data:geometry:wing:area"]
root_chord = inputs["data:geometry:wing:root:chord"]
tip_chord = inputs["data:geometry:wing:tip:chord"]
root_thickness_ratio = inputs["data:geometry:wing:root:thickness_ratio"]
tip_thickness_ratio = inputs["data:geometry:wing:tip:thickness_ratio"]
if fuel_type == 1.0:
m_vol_fuel = 718.9 # gasoline volume-mass [kg/m**3], cold worst case, Avgas
elif fuel_type == 2.0:
m_vol_fuel = 860.0 # Diesel volume-mass [kg/m**3], cold worst case
elif fuel_type == 3.0:
m_vol_fuel = 804.0 # Jet-A1 volume mass [kg/m**3], cold worst case
else:
m_vol_fuel = 718.9
ave_thickness = (
0.7 * (root_chord * root_thickness_ratio + tip_chord * tip_thickness_ratio) / 2.0
)
partials["data:weight:aircraft:MFW", "data:geometry:wing:area"] = (
0.3 * ave_thickness * m_vol_fuel
)
partials["data:weight:aircraft:MFW", "data:geometry:wing:root:chord"] = (
0.105 * m_vol_fuel * root_thickness_ratio * wing_area
)
partials["data:weight:aircraft:MFW", "data:geometry:wing:tip:chord"] = (
0.105 * m_vol_fuel * tip_thickness_ratio * wing_area
)
partials["data:weight:aircraft:MFW", "data:geometry:wing:root:thickness_ratio"] = (
0.105 * m_vol_fuel * root_chord * wing_area
)
partials["data:weight:aircraft:MFW", "data:geometry:wing:tip:thickness_ratio"] = (
0.105 * m_vol_fuel * tip_chord * wing_area
)