"""
Estimation of control surfaces center of gravity
"""
# 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
[docs]class ComputeControlSurfacesCG(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Control surfaces center of gravity estimation """
[docs] def setup(self):
self.add_input("data:geometry:wing:MAC:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC:leading_edge:x:local", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC: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:root:y", val=np.nan, units="m")
self.add_input("data:geometry:wing:kink:leading_edge:x:local", val=np.nan, units="m")
self.add_input("data:geometry:wing:kink:y", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC:at25percent:x", val=np.nan, units="m")
self.add_output("data:weight:airframe:flight_controls:CG:x", units="m")
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs):
l0_wing = inputs["data:geometry:wing:MAC:length"]
x0_wing = inputs["data:geometry:wing:MAC:leading_edge:x:local"]
y0_wing = inputs["data:geometry:wing:MAC:y"]
l2_wing = inputs["data:geometry:wing:root:chord"]
l3_wing = inputs["data:geometry:wing:kink:chord"]
y2_wing = inputs["data:geometry:wing:root:y"]
x3_wing = inputs["data:geometry:wing:kink:leading_edge:x:local"]
y3_wing = inputs["data:geometry:wing:kink:y"]
fa_length = inputs["data:geometry:wing:MAC:at25percent:x"]
# TODO: build generic functions to estimate the chord, leading edge,
# trailing edge with respect to span wise position
x_leading_edge = x3_wing * (y0_wing - y2_wing) / (y3_wing - y2_wing)
l_cg_control = l2_wing + (y0_wing - y2_wing) / (y3_wing - y2_wing) * (l3_wing - l2_wing)
x_cg_control = x_leading_edge + l_cg_control
x_cg_control_absolute = fa_length - 0.25 * l0_wing - x0_wing + x_cg_control
outputs["data:weight:airframe:flight_controls:CG:x"] = x_cg_control_absolute