"""
Python module for vertical tail mean aerodynamic chord calculation, part of the vertical tail
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
[docs]class ComputeVTMAC(om.ExplicitComponent):
# TODO: Document equations. Cite sources
"""
Vertical tail mean aerodynamic chord estimations.
"""
# pylint: disable=missing-function-docstring
# Overriding OpenMDAO setup
[docs] def setup(self):
self.add_input("data:geometry:vertical_tail:root:chord", val=np.nan, units="m")
self.add_input("data:geometry:vertical_tail:tip:chord", val=np.nan, units="m")
self.add_input("data:geometry:vertical_tail:span", val=np.nan, units="m")
self.add_output("data:geometry:vertical_tail:MAC:length", units="m")
self.add_output("data:geometry:vertical_tail:MAC:z", units="m")
self.declare_partials("data:geometry:vertical_tail:MAC:z", "*", method="exact")
self.declare_partials(
"data:geometry:vertical_tail:MAC:length",
["data:geometry:vertical_tail:root:chord", "data:geometry:vertical_tail:tip:chord"],
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):
root_chord = inputs["data:geometry:vertical_tail:root:chord"]
tip_chord = inputs["data:geometry:vertical_tail:tip:chord"]
b_v = inputs["data:geometry:vertical_tail:span"]
chord_sum = root_chord + tip_chord
mac_vt = (chord_sum**2.0 - root_chord * tip_chord) / (1.5 * chord_sum)
z0_vt = b_v * (chord_sum + tip_chord) / (3.0 * chord_sum)
outputs["data:geometry:vertical_tail:MAC:length"] = mac_vt
outputs["data:geometry:vertical_tail:MAC:z"] = z0_vt
# 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):
root_chord = inputs["data:geometry:vertical_tail:root:chord"]
tip_chord = inputs["data:geometry:vertical_tail:tip:chord"]
b_v = inputs["data:geometry:vertical_tail:span"]
chord_sum = root_chord + tip_chord
partials[
"data:geometry:vertical_tail:MAC:length", "data:geometry:vertical_tail:root:chord"
] = (1.0 - (tip_chord / chord_sum) ** 2.0) / 1.5
partials[
"data:geometry:vertical_tail:MAC:length", "data:geometry:vertical_tail:tip:chord"
] = (1.0 - (root_chord / chord_sum) ** 2.0) / 1.5
partials["data:geometry:vertical_tail:MAC:z", "data:geometry:vertical_tail:span"] = (
chord_sum + tip_chord
) / (3.0 * chord_sum)
partials["data:geometry:vertical_tail:MAC:z", "data:geometry:vertical_tail:root:chord"] = (
-b_v * tip_chord / (3.0 * chord_sum**2.0)
)
partials["data:geometry:vertical_tail:MAC:z", "data:geometry:vertical_tail:tip:chord"] = (
b_v * root_chord / (3.0 * chord_sum**2.0)
)