"""
Estimation of paint 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
import openmdao.api as om
[docs]class PaintWeight(om.ExplicitComponent):
"""
Weight estimation for paint
Based on formula in :cite:`supaero:2014`, mass contribution A7
"""
[docs] def setup(self):
self.add_input("data:geometry:aircraft:wetted_area", val=np.nan, units="m**2")
self.add_input("tuning:weight:airframe:paint:mass:k", val=1.0)
self.add_input("tuning:weight:airframe:paint:mass:offset", val=0.0, units="kg")
self.add_output("data:weight:airframe:paint:mass", units="kg")
[docs] def setup_partials(self):
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
total_wet_surface = inputs["data:geometry:aircraft:wetted_area"]
k_a7 = inputs["tuning:weight:airframe:paint:mass:k"]
offset_a7 = inputs["tuning:weight:airframe:paint:mass:offset"]
temp_a7 = 0.180 * total_wet_surface
outputs["data:weight:airframe:paint:mass"] = k_a7 * temp_a7 + offset_a7