"""
Computes Mach number and unitary Reynolds.
"""
# This file is part of FAST-OAD_CS23 : A framework for rapid Overall Aircraft Design
# Copyright (C) 2022 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 stdatm import Atmosphere
[docs]class ComputeUnitReynolds(ExplicitComponent):
"""
Computes the mach number and reynolds number based on inputs and the ISA model.
"""
[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:TLAR:v_approach", val=np.nan, units="m/s")
self.add_output("data:aerodynamics:low_speed:mach")
self.add_output("data:aerodynamics:low_speed:unit_reynolds", units="m**-1")
else:
self.add_input("data:TLAR:v_cruise", val=np.nan, units="m/s")
self.add_input("data:mission:sizing:main_route:cruise:altitude", val=np.nan, units="m")
self.add_output("data:aerodynamics:cruise:mach")
self.add_output("data:aerodynamics:cruise:unit_reynolds", units="m**-1")
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
if self.options["low_speed_aero"]:
altitude = 0.0
mach = inputs["data:TLAR:v_approach"] / Atmosphere(altitude).speed_of_sound
else:
altitude = float(inputs["data:mission:sizing:main_route:cruise:altitude"])
mach = (
inputs["data:TLAR:v_cruise"]
/ Atmosphere(altitude, altitude_in_feet=False).speed_of_sound
)
atm = Atmosphere(altitude, altitude_in_feet=False)
atm.mach = mach
unit_reynolds = atm.unitary_reynolds
if self.options["low_speed_aero"]:
outputs["data:aerodynamics:low_speed:mach"] = mach
outputs["data:aerodynamics:low_speed:unit_reynolds"] = unit_reynolds
else:
outputs["data:aerodynamics:cruise:mach"] = mach
outputs["data:aerodynamics:cruise:unit_reynolds"] = unit_reynolds