"""
Estimation of wing mean aerodynamic chord
"""
# 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: it would be good to have a function to compute MAC for HT, VT and WING
[docs]class ComputeMACWing(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Wing mean aerodynamic chord estimation """
[docs] def setup(self):
self.add_input("data:geometry:wing:area", val=np.nan, units="m**2")
self.add_input("data:geometry:wing:kink:leading_edge:x:local", val=np.nan, units="m")
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:kink: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:kink: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")
[docs] def setup_partials(self):
self.declare_partials(
"data:geometry:wing:MAC:length",
[
"data:geometry:wing:root:y",
"data:geometry:wing:kink:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:kink:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="fd",
)
self.declare_partials(
"data:geometry:wing:MAC:leading_edge:x:local",
[
"data:geometry:wing:kink:leading_edge:x:local",
"data:geometry:wing:tip:leading_edge:x:local",
"data:geometry:wing:root:y",
"data:geometry:wing:kink:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:kink:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="fd",
)
self.declare_partials(
"data:geometry:wing:MAC:y",
[
"data:geometry:wing:root:y",
"data:geometry:wing:kink:y",
"data:geometry:wing:tip:y",
"data:geometry:wing:root:chord",
"data:geometry:wing:kink:chord",
"data:geometry:wing:tip:chord",
"data:geometry:wing:area",
],
method="fd",
)
[docs] def compute(self, inputs, outputs):
wing_area = inputs["data:geometry:wing:area"]
x3_wing = inputs["data:geometry:wing:kink:leading_edge:x:local"]
x4_wing = inputs["data:geometry:wing:tip:leading_edge:x:local"]
y2_wing = inputs["data:geometry:wing:root:y"]
y3_wing = inputs["data:geometry:wing:kink:y"]
y4_wing = inputs["data:geometry:wing:tip:y"]
l2_wing = inputs["data:geometry:wing:root:chord"]
l3_wing = inputs["data:geometry:wing:kink:chord"]
l4_wing = inputs["data:geometry:wing:tip:chord"]
l0_wing = (
3 * y2_wing * l2_wing ** 2
+ (y3_wing - y2_wing) * (l2_wing ** 2 + l3_wing ** 2 + l2_wing * l3_wing)
+ (y4_wing - y3_wing) * (l3_wing ** 2 + l4_wing ** 2 + l3_wing * l4_wing)
) * (2 / (3 * wing_area))
x0_wing = (
x3_wing
* (
(y3_wing - y2_wing) * (2 * l3_wing + l2_wing)
+ (y4_wing - y3_wing) * (2 * l3_wing + l4_wing)
)
+ x4_wing * (y4_wing - y3_wing) * (2 * l4_wing + l3_wing)
) / (3 * wing_area)
y0_wing = (
3 * y2_wing ** 2 * l2_wing
+ (y3_wing - y2_wing)
* (l3_wing * (y2_wing + 2 * y3_wing) + l2_wing * (y3_wing + 2 * y2_wing))
+ (y4_wing - y3_wing)
* (l4_wing * (y3_wing + 2 * y4_wing) + l3_wing * (y4_wing + 2 * y3_wing))
) / (3 * 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