"""
Python module for wing mean aerodynamic chord calculation, part of the wing geometry.
"""
# 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 numpy as np
import openmdao.api as om
import fastoad.api as oad
from ..constants import SERVICE_WING_MAC, SUBMODEL_WING_MAC_LEGACY
[docs]@oad.RegisterSubmodel(SERVICE_WING_MAC, SUBMODEL_WING_MAC_LEGACY)
class ComputeWingMAC(om.ExplicitComponent):
"""Wing mean aerodynamic chord estimation, obtained from :cite:`supaero:2014`."""
# pylint: disable=missing-function-docstring
# Overriding OpenMDAO setup
[docs] def setup(self):
self.add_input("data:geometry:wing:area", val=np.nan, units="m**2")
self.add_input("data:geometry:wing:tip:leading_edge:x:local", val=np.nan, units="m")
self.add_input("data:geometry:wing:root:y", val=np.nan, units="m")
self.add_input("data:geometry:wing:tip:y", val=np.nan, units="m")
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_output("data:geometry:wing:MAC:length", units="m")
self.add_output("data:geometry:wing:MAC:leading_edge:x:local", units="m")
self.add_output("data:geometry:wing:MAC:y", units="m")
self.declare_partials(
"data:geometry:wing:MAC:length",
[
"data:geometry:wing:root:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="exact",
)
self.declare_partials(
"data:geometry:wing:MAC:leading_edge:x:local",
[
"data:geometry:wing:tip:leading_edge:x:local",
"data:geometry:wing:root:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="exact",
)
self.declare_partials(
"data:geometry:wing:MAC:y",
[
"data:geometry:wing:root:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="exact",
)
# 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):
wing_area = inputs["data:geometry:wing:area"]
x4_wing = inputs["data:geometry:wing:tip:leading_edge:x:local"]
y2_wing = inputs["data:geometry:wing:root:y"]
y4_wing = inputs["data:geometry:wing:tip:y"]
l2_wing = inputs["data:geometry:wing:root:chord"]
l4_wing = inputs["data:geometry:wing:tip:chord"]
l0_wing = (
3.0 * y2_wing * l2_wing**2.0
+ (y4_wing - y2_wing) * (l2_wing**2.0 + l4_wing**2.0 + l2_wing * l4_wing)
) * (2.0 / (3.0 * wing_area))
x0_wing = (x4_wing * ((y4_wing - y2_wing) * (2.0 * l4_wing + l2_wing))) / (3.0 * wing_area)
y0_wing = (
3.0 * y2_wing**2.0 * l2_wing
+ (y4_wing - y2_wing)
* (l4_wing * (y2_wing + 2.0 * y4_wing) + l2_wing * (y4_wing + 2.0 * y2_wing))
) / (3.0 * wing_area)
outputs["data:geometry:wing:MAC:length"] = l0_wing
outputs["data:geometry:wing:MAC:leading_edge:x:local"] = x0_wing
outputs["data:geometry:wing:MAC:y"] = y0_wing
# 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):
wing_area = inputs["data:geometry:wing:area"]
x4_wing = inputs["data:geometry:wing:tip:leading_edge:x:local"]
y2_wing = inputs["data:geometry:wing:root:y"]
y4_wing = inputs["data:geometry:wing:tip:y"]
l2_wing = inputs["data:geometry:wing:root:chord"]
l4_wing = inputs["data:geometry:wing:tip:chord"]
partials["data:geometry:wing:MAC:length", "data:geometry:wing:area"] = (
2.0
* (
(y2_wing - y4_wing) * (l2_wing**2.0 + l2_wing * l4_wing + l4_wing**2.0)
- 3.0 * l2_wing**2.0 * y2_wing
)
) / (3.0 * wing_area**2.0)
partials["data:geometry:wing:MAC:length", "data:geometry:wing:root:y"] = -(
2.0 * (-2.0 * l2_wing**2.0 + l2_wing * l4_wing + l4_wing**2.0)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:length", "data:geometry:wing:tip:y"] = (
2.0 * (l2_wing**2.0 + l2_wing * l4_wing + l4_wing**2.0)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:length", "data:geometry:wing:root:chord"] = (
2.0 * (6.0 * l2_wing * y2_wing - (2.0 * l2_wing + l4_wing) * (y2_wing - y4_wing))
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:length", "data:geometry:wing:tip:chord"] = -(
2.0 * (l2_wing + 2.0 * l4_wing) * (y2_wing - y4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:leading_edge:x:local", "data:geometry:wing:area"] = (
x4_wing * (l2_wing + 2.0 * l4_wing) * (y2_wing - y4_wing)
) / (3.0 * wing_area**2.0)
partials[
"data:geometry:wing:MAC:leading_edge:x:local",
"data:geometry:wing:tip:leading_edge:x:local",
] = -((l2_wing + 2.0 * l4_wing) * (y2_wing - y4_wing)) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:leading_edge:x:local", "data:geometry:wing:root:y"] = -(
x4_wing * (l2_wing + 2.0 * l4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:leading_edge:x:local", "data:geometry:wing:tip:y"] = (
x4_wing * (l2_wing + 2.0 * l4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:leading_edge:x:local", "data:geometry:wing:root:chord"] = (
-(x4_wing * (y2_wing - y4_wing)) / (3.0 * wing_area)
)
partials["data:geometry:wing:MAC:leading_edge:x:local", "data:geometry:wing:tip:chord"] = -(
2.0 * x4_wing * (y2_wing - y4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:y", "data:geometry:wing:area"] = (
(l2_wing * (2.0 * y2_wing + y4_wing) + l4_wing * (y2_wing + 2.0 * y4_wing))
* (y2_wing - y4_wing)
- 3.0 * l2_wing * y2_wing**2.0
) / (3.0 * wing_area**2.0)
partials["data:geometry:wing:MAC:y", "data:geometry:wing:root:y"] = -(
l2_wing * (2.0 * y2_wing + y4_wing)
- 6.0 * l2_wing * y2_wing
+ l4_wing * (y2_wing + 2.0 * y4_wing)
+ (2.0 * l2_wing + l4_wing) * (y2_wing - y4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:y", "data:geometry:wing:tip:y"] = (
l2_wing * (2.0 * y2_wing + y4_wing)
+ l4_wing * (y2_wing + 2.0 * y4_wing)
- (l2_wing + 2.0 * l4_wing) * (y2_wing - y4_wing)
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:y", "data:geometry:wing:root:chord"] = -(
(y2_wing - y4_wing) * (2.0 * y2_wing + y4_wing) - 3.0 * y2_wing**2.0
) / (3.0 * wing_area)
partials["data:geometry:wing:MAC:y", "data:geometry:wing:tip:chord"] = -(
(y2_wing - y4_wing) * (y2_wing + 2.0 * y4_wing)
) / (3.0 * wing_area)