"""
Estimation of navigation systems weight
"""
# This file is part of FAST-OAD : A framework for rapid Overall Aircraft Design
# Copyright (C) 2020 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 NavigationSystemsWeight(ExplicitComponent):
"""
Weight estimation for navigation systems
Based on figures in :cite:`supaero:2014`, mass contribution C3
"""
[docs] def setup(self):
self.add_input("data:TLAR:range", val=np.nan, units="NM")
self.add_input("data:geometry:fuselage:length", val=np.nan, units="m")
self.add_input("data:geometry:wing:b_50", val=np.nan, units="m")
self.add_input("tuning:weight:systems:navigation:mass:k", val=1.0)
self.add_input("tuning:weight:systems:navigation:mass:offset", val=0.0, units="kg")
self.add_output("data:weight:systems:navigation:mass", units="kg")
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
tlar_range = inputs["data:TLAR:range"]
fuselage_length = inputs["data:geometry:fuselage:length"]
b_50 = inputs["data:geometry:wing:b_50"]
k_c3 = inputs["tuning:weight:systems:navigation:mass:k"]
offset_c3 = inputs["tuning:weight:systems:navigation:mass:offset"]
if tlar_range in RangeCategory.SHORT:
base_weight = 150.0
elif tlar_range in RangeCategory.SHORT_MEDIUM:
base_weight = 450.0
elif tlar_range in RangeCategory.MEDIUM:
base_weight = 700.0
else:
base_weight = 800.0
temp_c3 = base_weight + 0.033 * fuselage_length * b_50
outputs["data:weight:systems:navigation:mass"] = k_c3 * temp_c3 + offset_c3