"""
Estimation of life support systems weight
"""
# 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
from fastoad.constants import RangeCategory
[docs]class LifeSupportSystemsWeight(ExplicitComponent):
"""
Weight estimation for life support systems
This includes:
- insulation
- air conditioning / pressurization
- de-icing
- internal lighting system
- seats and installation of crew
- fixed oxygen
- permanent security kits
Based on formulas in :cite:`supaero:2014`, mass contribution C2
"""
[docs] def setup(self):
self.add_input("data:TLAR:range", val=np.nan, units="NM")
self.add_input("data:geometry:fuselage:maximum_width", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:maximum_height", val=np.nan, units="m")
self.add_input("data:geometry:cabin:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:sweep_0", val=np.nan, units="rad")
self.add_input("data:geometry:propulsion:nacelle:diameter", val=np.nan, units="m")
self.add_input("data:geometry:propulsion:engine:count", val=np.nan)
self.add_input("data:geometry:cabin:NPAX1", val=np.nan)
self.add_input("data:geometry:cabin:crew_count:technical", val=np.nan)
self.add_input("data:geometry:cabin:crew_count:commercial", val=np.nan)
self.add_input("data:geometry:wing:span", val=np.nan, units="m")
self.add_input("data:weight:propulsion:engine:mass", val=np.nan, units="kg")
self.add_input("tuning:weight:systems:life_support:insulation:mass:k", val=1.0)
self.add_input(
"tuning:weight:systems:life_support:insulation:mass:offset", val=0.0, units="kg"
)
self.add_input("tuning:weight:systems:life_support:air_conditioning:mass:k", val=1.0)
self.add_input(
"tuning:weight:systems:life_support:air_conditioning:mass:offset", val=0.0, units="kg"
)
self.add_input("tuning:weight:systems:life_support:de-icing:mass:k", val=1.0)
self.add_input(
"tuning:weight:systems:life_support:de-icing:mass:offset", val=0.0, units="kg"
)
self.add_input("tuning:weight:systems:life_support:cabin_lighting:mass:k", val=1.0)
self.add_input(
"tuning:weight:systems:life_support:cabin_lighting:mass:offset", val=0.0, units="kg"
)
self.add_input(
"tuning:weight:systems:life_support:seats_crew_accommodation:mass:k", val=1.0
)
self.add_input(
"tuning:weight:systems:life_support:seats_crew_accommodation:mass:offset",
val=0.0,
units="kg",
)
self.add_input("tuning:weight:systems:life_support:oxygen:mass:k", val=1.0)
self.add_input("tuning:weight:systems:life_support:oxygen:mass:offset", val=0.0, units="kg")
self.add_input("tuning:weight:systems:life_support:safety_equipment:mass:k", val=1.0)
self.add_input(
"tuning:weight:systems:life_support:safety_equipment:mass:offset", val=0.0, units="kg"
)
self.add_output("data:weight:systems:life_support:insulation:mass", units="kg")
self.add_output("data:weight:systems:life_support:air_conditioning:mass", units="kg")
self.add_output("data:weight:systems:life_support:de-icing:mass", units="kg")
self.add_output("data:weight:systems:life_support:cabin_lighting:mass", units="kg")
self.add_output(
"data:weight:systems:life_support:seats_crew_accommodation:mass", units="kg"
)
self.add_output("data:weight:systems:life_support:oxygen:mass", units="kg")
self.add_output("data:weight:systems:life_support:safety_equipment:mass", units="kg")
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
# pylint: disable=too-many-locals
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
tlar_range = inputs["data:TLAR:range"]
width_max = inputs["data:geometry:fuselage:maximum_width"]
height_max = inputs["data:geometry:fuselage:maximum_height"]
cabin_length = inputs["data:geometry:cabin:length"]
sweep_leading_edge = inputs["data:geometry:wing:sweep_0"]
n_engines = inputs["data:geometry:propulsion:engine:count"]
span = inputs["data:geometry:wing:span"]
nacelle_diameter = inputs["data:geometry:propulsion:nacelle:diameter"]
npax1 = inputs["data:geometry:cabin:NPAX1"]
weight_engines = inputs["data:weight:propulsion:engine:mass"]
cabin_crew = inputs["data:geometry:cabin:crew_count:commercial"]
cockpit_crew = inputs["data:geometry:cabin:crew_count:technical"]
k_c21 = inputs["tuning:weight:systems:life_support:insulation:mass:k"]
offset_c21 = inputs["tuning:weight:systems:life_support:insulation:mass:offset"]
k_c22 = inputs["tuning:weight:systems:life_support:air_conditioning:mass:k"]
offset_c22 = inputs["tuning:weight:systems:life_support:air_conditioning:mass:offset"]
k_c23 = inputs["tuning:weight:systems:life_support:de-icing:mass:k"]
offset_c23 = inputs["tuning:weight:systems:life_support:de-icing:mass:offset"]
k_c24 = inputs["tuning:weight:systems:life_support:cabin_lighting:mass:k"]
offset_c24 = inputs["tuning:weight:systems:life_support:cabin_lighting:mass:offset"]
k_c25 = inputs["tuning:weight:systems:life_support:seats_crew_accommodation:mass:k"]
offset_c25 = inputs[
"tuning:weight:systems:life_support:seats_crew_accommodation:mass:offset"
]
k_c26 = inputs["tuning:weight:systems:life_support:oxygen:mass:k"]
offset_c26 = inputs["tuning:weight:systems:life_support:oxygen:mass:offset"]
k_c27 = inputs["tuning:weight:systems:life_support:safety_equipment:mass:k"]
offset_c27 = inputs["tuning:weight:systems:life_support:safety_equipment:mass:offset"]
fuselage_diameter = np.sqrt(width_max * height_max)
# Mass of insulating system
temp_c21 = 9.3 * fuselage_diameter * cabin_length
outputs["data:weight:systems:life_support:insulation:mass"] = k_c21 * temp_c21 + offset_c21
# Mass of air conditioning and pressurization system
if tlar_range <= RangeCategory.MEDIUM.max():
temp_c22 = (
200
+ 27 * npax1 ** 0.46
+ 7.2 * (n_engines ** 0.7) * (npax1 ** 0.64)
+ npax1
+ 0.0029 * npax1 ** 1.64
)
else:
temp_c22 = (
450
+ 51 * npax1 ** 0.46
+ 7.2 * (n_engines ** 0.7) * (npax1 ** 0.64)
+ npax1
+ 0.0029 * npax1 ** 1.64
)
outputs["data:weight:systems:life_support:air_conditioning:mass"] = (
k_c22 * temp_c22 + offset_c22
)
# Mass of de-icing system
temp_c23 = (
53
+ 9.5 * nacelle_diameter * n_engines
+ 1.9 * (span - width_max) / np.cos(sweep_leading_edge)
)
outputs["data:weight:systems:life_support:de-icing:mass"] = k_c23 * temp_c23 + offset_c23
# Mass of internal lighting system
temp_c24 = 1.4 * cabin_length * fuselage_diameter
outputs["data:weight:systems:life_support:cabin_lighting:mass"] = (
k_c24 * temp_c24 + offset_c24
)
# Mass of seats and installation system
temp_c25 = 27 * cockpit_crew + 18 * cabin_crew
outputs["data:weight:systems:life_support:seats_crew_accommodation:mass"] = (
k_c25 * temp_c25 + offset_c25
)
# Mass of fixed oxygen
temp_c26 = 80 + 1.3 * npax1
outputs["data:weight:systems:life_support:oxygen:mass"] = k_c26 * temp_c26 + offset_c26
# Mass of permanent security kits
temp_c27 = 0.01 * weight_engines + 2.30 * npax1
outputs["data:weight:systems:life_support:safety_equipment:mass"] = (
k_c27 * temp_c27 + offset_c27
)