"""
FAST - Copyright (c) 2016 ONERA ISAE
"""
# 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
import openmdao.api as om
from fastoad.models.weight.cg.cg_components import (
ComputeControlSurfacesCG,
ComputeGlobalCG,
ComputeHTcg,
ComputeOthersCG,
ComputeTanksCG,
ComputeVTcg,
ComputeWingCG,
UpdateMLG,
)
[docs]class CG(om.Group):
""" Model that computes the global center of gravity """
[docs] def setup(self):
self.add_subsystem("ht_cg", ComputeHTcg(), promotes=["*"])
self.add_subsystem("vt_cg", ComputeVTcg(), promotes=["*"])
self.add_subsystem("compute_cg_wing", ComputeWingCG(), promotes=["*"])
self.add_subsystem("compute_cg_control_surface", ComputeControlSurfacesCG(), promotes=["*"])
self.add_subsystem("compute_cg_tanks", ComputeTanksCG(), promotes=["*"])
self.add_subsystem("compute_cg_others", ComputeOthersCG(), promotes=["*"])
self.add_subsystem("compute_cg", ComputeGlobalCG(), promotes=["*"])
self.add_subsystem("update_mlg", UpdateMLG(), promotes=["*"])
self.add_subsystem("aircraft", ComputeAircraftCG(), promotes=["*"])
# Solvers setup
self.nonlinear_solver = om.NonlinearBlockGS()
self.nonlinear_solver.options["iprint"] = 0
self.nonlinear_solver.options["maxiter"] = 200
self.linear_solver = om.LinearBlockGS()
self.linear_solver.options["iprint"] = 0
[docs]class ComputeAircraftCG(om.ExplicitComponent):
""" Compute position of aircraft CG from CG ratio """
[docs] def setup(self):
self.add_input("data:weight:aircraft:CG:aft:MAC_position", val=np.nan)
self.add_input("data:geometry:wing:MAC:at25percent:x", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC:length", val=np.nan, units="m")
self.add_output("data:weight:aircraft:CG:aft:x", units="m")
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs):
cg_ratio = inputs["data:weight:aircraft:CG:aft:MAC_position"]
l0_wing = inputs["data:geometry:wing:MAC:length"]
mac_position = inputs["data:geometry:wing:MAC:at25percent:x"]
outputs["data:weight:aircraft:CG:aft:x"] = (
mac_position - 0.25 * l0_wing + cg_ratio * l0_wing
)