"""
Estimation of wing chords (l1 and l4)
"""
# 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 math
import numpy as np
from openmdao.core.explicitcomponent import ExplicitComponent
[docs]class ComputeL1AndL4Wing(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Wing chords (l1 and l4) estimation """
[docs] def setup(self):
self.add_input("data:geometry:wing:area", val=np.nan, units="m**2")
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:span", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:maximum_width", val=np.nan, units="m")
self.add_input("data:geometry:wing:taper_ratio", val=np.nan)
self.add_input("data:geometry:wing:sweep_25", val=np.nan, units="deg")
self.add_output("data:geometry:wing:root:virtual_chord", units="m")
self.add_output("data:geometry:wing:tip:chord", units="m")
[docs] def setup_partials(self):
self.declare_partials("data:geometry:wing:root:virtual_chord", "*", method="fd")
self.declare_partials("data:geometry:wing:tip:chord", "*", method="fd")
[docs] def compute(self, inputs, outputs):
wing_area = inputs["data:geometry:wing:area"]
span = inputs["data:geometry:wing:span"]
y2_wing = inputs["data:geometry:wing:root:y"]
y3_wing = inputs["data:geometry:wing:kink:y"]
sweep_25 = inputs["data:geometry:wing:sweep_25"]
width_max = inputs["data:geometry:fuselage:maximum_width"]
taper_ratio = inputs["data:geometry:wing:taper_ratio"]
l1_wing = (
wing_area
- (y3_wing - y2_wing) * (y3_wing + y2_wing) * math.tan(sweep_25 / 180.0 * math.pi)
) / (
(1.0 + taper_ratio) / 2.0 * (span - width_max)
+ width_max
- (3.0 * (1.0 - taper_ratio) * (y3_wing - y2_wing) * (y3_wing + y2_wing))
/ (2.0 * (span - width_max))
)
l4_wing = l1_wing * taper_ratio
outputs["data:geometry:wing:root:virtual_chord"] = l1_wing
outputs["data:geometry:wing:tip:chord"] = l4_wing