"""Computation of trim drag."""
# 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.module_management.service_registry import RegisterSubmodel
from ..constants import SERVICE_CD_TRIM
[docs]@RegisterSubmodel(SERVICE_CD_TRIM, "fastoad.submodel.aerodynamics.CD.trim.legacy")
class CdTrim(om.ExplicitComponent):
"""Computation of trim drag."""
[docs] def initialize(self):
self.options.declare("low_speed_aero", default=False, types=bool)
[docs] def setup(self):
if self.options["low_speed_aero"]:
self.add_input(
"data:aerodynamics:aircraft:low_speed:CL", shape_by_conn=True, val=np.nan
)
self.add_output(
"data:aerodynamics:aircraft:low_speed:CD:trim",
copy_shape="data:aerodynamics:aircraft:low_speed:CL",
)
else:
self.add_input("data:aerodynamics:aircraft:cruise:CL", shape_by_conn=True, val=np.nan)
self.add_output(
"data:aerodynamics:aircraft:cruise:CD:trim",
copy_shape="data:aerodynamics:aircraft:cruise:CL",
)
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
if self.options["low_speed_aero"]:
cl = inputs["data:aerodynamics:aircraft:low_speed:CL"]
else:
cl = inputs["data:aerodynamics:aircraft:cruise:CL"]
cd_trim = []
for cl_val in cl:
cd_trim.append(5.89 * pow(10, -4) * cl_val)
if self.options["low_speed_aero"]:
outputs["data:aerodynamics:aircraft:low_speed:CD:trim"] = cd_trim
else:
outputs["data:aerodynamics:aircraft:cruise:CD:trim"] = cd_trim