"""
Estimation of other components center of gravities
"""
# 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 ComputeOthersCG(ExplicitComponent):
# TODO: Document equations. Cite sources
""" Other components center of gravities estimation """
[docs] def setup(self):
self.add_input("data:geometry:wing:MAC:leading_edge:x:local", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:root:chord", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:MAC:at25percent:x", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:front_length", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:rear_length", val=np.nan, units="m")
self.add_input("data:weight:propulsion:engine:CG:x", val=np.nan, units="m")
self.add_input("data:weight:furniture:passenger_seats:CG:x", val=np.nan, units="m")
self.add_input("data:weight:propulsion:engine:mass", val=np.nan, units="kg")
self.add_input("data:geometry:cabin:NPAX1", val=np.nan)
self.add_input("data:geometry:cabin:seats:economical:count_by_row", val=np.nan)
self.add_input("data:geometry:cabin:seats:economical:length", val=np.nan, units="m")
# TODO: add description of these CGs
self.add_output("data:weight:airframe:fuselage:CG:x", units="m")
self.add_output("data:weight:airframe:landing_gear:front:CG:x", units="m")
self.add_output("data:weight:airframe:pylon:CG:x", units="m")
self.add_output("data:weight:airframe:paint:CG:x", units="m")
self.add_output("data:weight:propulsion:fuel_lines:CG:x", units="m")
self.add_output("data:weight:propulsion:unconsumables:CG:x", units="m")
self.add_output("data:weight:systems:power:auxiliary_power_unit:CG:x", units="m")
self.add_output("data:weight:systems:power:electric_systems:CG:x", units="m")
self.add_output("data:weight:systems:power:hydraulic_systems:CG:x", units="m")
self.add_output("data:weight:systems:life_support:insulation:CG:x", units="m")
self.add_output("data:weight:systems:life_support:air_conditioning:CG:x", units="m")
self.add_output("data:weight:systems:life_support:de-icing:CG:x", units="m")
self.add_output("data:weight:systems:life_support:cabin_lighting:CG:x", units="m")
self.add_output("data:weight:systems:life_support:seats_crew_accommodation:CG:x", units="m")
self.add_output("data:weight:systems:life_support:oxygen:CG:x", units="m")
self.add_output("data:weight:systems:life_support:safety_equipment:CG:x", units="m")
self.add_output("data:weight:systems:navigation:CG:x", units="m")
self.add_output("data:weight:systems:transmission:CG:x", units="m")
self.add_output("data:weight:systems:operational:radar:CG:x", units="m")
self.add_output("data:weight:systems:operational:cargo_hold:CG:x", units="m")
self.add_output("data:weight:furniture:food_water:CG:x", units="m")
self.add_output("data:weight:furniture:security_kit:CG:x", units="m")
self.add_output("data:weight:furniture:toilets:CG:x", units="m")
self.add_output("data:weight:payload:PAX:CG:x", units="m")
self.add_output("data:weight:payload:rear_fret:CG:x", units="m")
self.add_output("data:weight:payload:front_fret:CG:x", units="m")
[docs] def setup_partials(self):
self.declare_partials(
"data:weight:airframe:fuselage:CG:x", "data:geometry:fuselage:length", method="fd"
)
self.declare_partials(
"data:weight:airframe:landing_gear:front:CG:x",
"data:geometry:fuselage:front_length",
method="fd",
)
self.declare_partials(
"data:weight:airframe:pylon:CG:x", "data:weight:propulsion:engine:CG:x", method="fd"
)
self.declare_partials(
"data:weight:propulsion:fuel_lines:CG:x",
"data:weight:propulsion:engine:CG:x",
method="fd",
)
self.declare_partials(
"data:weight:propulsion:unconsumables:CG:x",
"data:weight:propulsion:engine:CG:x",
method="fd",
)
self.declare_partials(
[
"data:weight:systems:power:auxiliary_power_unit:CG:x",
"data:weight:systems:power:electric_systems:CG:x",
"data:weight:systems:power:hydraulic_systems:CG:x",
"data:weight:systems:life_support:insulation:CG:x",
"data:weight:systems:life_support:cabin_lighting:CG:x",
"data:weight:systems:transmission:CG:x",
"data:weight:systems:operational:radar:CG:x",
],
"data:geometry:fuselage:length",
method="fd",
)
self.declare_partials(
[
"data:weight:systems:life_support:air_conditioning:CG:x",
"data:weight:systems:life_support:seats_crew_accommodation:CG:x",
"data:weight:systems:life_support:oxygen:CG:x",
"data:weight:systems:operational:cargo_hold:CG:x",
],
"data:weight:furniture:passenger_seats:CG:x",
method="fd",
)
self.declare_partials(
"data:weight:systems:life_support:de-icing:CG:x",
["data:geometry:wing:MAC:at25percent:x", "data:geometry:wing:MAC:length"],
method="fd",
)
self.declare_partials(
"data:weight:systems:life_support:safety_equipment:CG:x",
[
"data:weight:propulsion:engine:mass",
"data:weight:propulsion:engine:CG:x",
"data:geometry:cabin:NPAX1",
"data:weight:furniture:passenger_seats:CG:x",
],
method="fd",
)
self.declare_partials(
"data:weight:systems:navigation:CG:x",
"data:geometry:fuselage:front_length",
method="fd",
)
self.declare_partials(
"data:weight:furniture:food_water:CG:x",
[
"data:geometry:fuselage:length",
"data:geometry:fuselage:rear_length",
"data:geometry:cabin:seats:economical:length",
"data:geometry:cabin:seats:economical:count_by_row",
],
method="fd",
)
self.declare_partials(
["data:weight:furniture:security_kit:CG:x", "data:weight:furniture:toilets:CG:x"],
"data:weight:furniture:passenger_seats:CG:x",
method="fd",
)
self.declare_partials(
"data:weight:payload:PAX:CG:x",
"data:weight:furniture:passenger_seats:CG:x",
method="fd",
)
self.declare_partials(
"data:weight:payload:rear_fret:CG:x",
[
"data:geometry:fuselage:rear_length",
"data:geometry:wing:MAC:length",
"data:geometry:wing:MAC:leading_edge:x:local",
"data:geometry:wing:root:chord",
"data:geometry:cabin:seats:economical:count_by_row",
"data:geometry:cabin:seats:economical:length",
"data:geometry:wing:MAC:at25percent:x",
"data:geometry:fuselage:length",
],
method="fd",
)
self.declare_partials(
"data:weight:payload:front_fret:CG:x",
[
"data:geometry:fuselage:front_length",
"data:geometry:wing:MAC:length",
"data:geometry:wing:MAC:leading_edge:x:local",
"data:geometry:wing:MAC:at25percent:x",
],
method="fd",
)
[docs] def compute(self, inputs, outputs):
x0_wing = inputs["data:geometry:wing:MAC:leading_edge:x:local"]
l0_wing = inputs["data:geometry:wing:MAC:length"]
l2_wing = inputs["data:geometry:wing:root:chord"]
fus_length = inputs["data:geometry:fuselage:length"]
fa_length = inputs["data:geometry:wing:MAC:at25percent:x"]
lav = inputs["data:geometry:fuselage:front_length"]
lar = inputs["data:geometry:fuselage:rear_length"]
x_cg_b1 = inputs["data:weight:propulsion:engine:CG:x"]
x_cg_d2 = inputs["data:weight:furniture:passenger_seats:CG:x"]
weight_engines = inputs["data:weight:propulsion:engine:mass"]
npax1 = inputs["data:geometry:cabin:NPAX1"]
front_seat_number_eco = inputs["data:geometry:cabin:seats:economical:count_by_row"]
ls_eco = inputs["data:geometry:cabin:seats:economical:length"]
x_cg_a2 = 0.45 * fus_length
# Assume cg of nose landing gear is at 75% of lav
x_cg_a52 = lav * 0.75
x_cg_a6 = x_cg_b1
x_cg_b2 = x_cg_b1
x_cg_b3 = x_cg_b1
# APU is installed after the pressure bulkhead, and pressurized area is
# about 80% of fuselage length
x_cg_c11 = 0.95 * fus_length
x_cg_c12 = 0.5 * fus_length
x_cg_c13 = 0.5 * fus_length
x_cg_c21 = 0.45 * fus_length
x_cg_c22 = x_cg_d2
x_cg_c23 = fa_length - 0.15 * l0_wing
x_cg_c24 = 0.45 * fus_length
x_cg_c25 = x_cg_d2
x_cg_c26 = x_cg_d2
x_cg_c27 = (0.01 * weight_engines * x_cg_b1 + 2.3 * npax1 * x_cg_d2) / (
0.01 * weight_engines + 2.3 * npax1
)
x_cg_c3 = lav * 0.8
x_cg_c4 = 0.5 * fus_length
x_cg_c51 = 0.02 * fus_length
x_cg_c52 = x_cg_d2
x_cg_d3 = lav + (fus_length - lav - lar) + ls_eco * front_seat_number_eco + 0.92 + 0.432
x_cg_d5 = x_cg_d2
length_front_fret = fa_length - 0.25 * l0_wing - x0_wing - lav
x_cg_front_fret = lav + length_front_fret * 0.5
length_rear_fret = (
fus_length
- lar
+ (front_seat_number_eco - 5) * ls_eco
- (lav + length_front_fret + 0.8 * l2_wing)
)
x_cg_rear_fret = lav + length_front_fret + 0.8 * l2_wing + length_rear_fret * 0.5
x_cg_pl = x_cg_d2
outputs["data:weight:airframe:fuselage:CG:x"] = x_cg_a2
outputs["data:weight:airframe:landing_gear:front:CG:x"] = x_cg_a52
outputs["data:weight:airframe:pylon:CG:x"] = x_cg_a6
outputs["data:weight:airframe:paint:CG:x"] = 0.0
outputs["data:weight:propulsion:fuel_lines:CG:x"] = x_cg_b2
outputs["data:weight:propulsion:unconsumables:CG:x"] = x_cg_b3
outputs["data:weight:systems:power:auxiliary_power_unit:CG:x"] = x_cg_c11
outputs["data:weight:systems:power:electric_systems:CG:x"] = x_cg_c12
outputs["data:weight:systems:power:hydraulic_systems:CG:x"] = x_cg_c13
outputs["data:weight:systems:life_support:insulation:CG:x"] = x_cg_c21
outputs["data:weight:systems:life_support:air_conditioning:CG:x"] = x_cg_c22
outputs["data:weight:systems:life_support:de-icing:CG:x"] = x_cg_c23
outputs["data:weight:systems:life_support:cabin_lighting:CG:x"] = x_cg_c24
outputs["data:weight:systems:life_support:seats_crew_accommodation:CG:x"] = x_cg_c25
outputs["data:weight:systems:life_support:oxygen:CG:x"] = x_cg_c26
outputs["data:weight:systems:life_support:safety_equipment:CG:x"] = x_cg_c27
outputs["data:weight:systems:navigation:CG:x"] = x_cg_c3
outputs["data:weight:systems:transmission:CG:x"] = x_cg_c4
outputs["data:weight:systems:operational:radar:CG:x"] = x_cg_c51
outputs["data:weight:systems:operational:cargo_hold:CG:x"] = x_cg_c52
outputs["data:weight:furniture:food_water:CG:x"] = x_cg_d3
outputs["data:weight:furniture:security_kit:CG:x"] = x_cg_d5
outputs["data:weight:furniture:toilets:CG:x"] = x_cg_d5
outputs["data:weight:payload:PAX:CG:x"] = x_cg_pl
outputs["data:weight:payload:rear_fret:CG:x"] = x_cg_rear_fret
outputs["data:weight:payload:front_fret:CG:x"] = x_cg_front_fret