"""
Estimation of horizontal tail chords and span
"""
# 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: is an OpenMDAO component required for this simple calculation ?
[docs]class ComputeHTChord(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Horizontal tail chords and span estimation """
[docs] def setup(self):
self.add_input("data:geometry:horizontal_tail:aspect_ratio", val=np.nan)
self.add_input("data:geometry:horizontal_tail:area", val=np.nan, units="m**2")
self.add_input("data:geometry:horizontal_tail:taper_ratio", val=np.nan)
self.add_output("data:geometry:horizontal_tail:span", units="m")
self.add_output("data:geometry:horizontal_tail:root:chord", units="m")
self.add_output("data:geometry:horizontal_tail:tip:chord", units="m")
[docs] def setup_partials(self):
self.declare_partials(
"data:geometry:horizontal_tail:span",
["data:geometry:horizontal_tail:area", "data:geometry:horizontal_tail:aspect_ratio"],
method="fd",
)
self.declare_partials("data:geometry:horizontal_tail:root:chord", "*", method="fd")
self.declare_partials("data:geometry:horizontal_tail:tip:chord", "*", method="fd")
[docs] def compute(self, inputs, outputs):
lambda_ht = inputs["data:geometry:horizontal_tail:aspect_ratio"]
s_h = inputs["data:geometry:horizontal_tail:area"]
taper_ht = inputs["data:geometry:horizontal_tail:taper_ratio"]
b_h = np.sqrt(max(lambda_ht * s_h, 0.1))
root_chord = s_h * 2 / (1 + taper_ht) / b_h
tip_chord = root_chord * taper_ht
outputs["data:geometry:horizontal_tail:span"] = b_h
outputs["data:geometry:horizontal_tail:root:chord"] = root_chord
outputs["data:geometry:horizontal_tail:tip:chord"] = tip_chord