Source code for RCAIDE.Framework.Analyses.Aeroacoustics.Physics_Based_Frequency_Domain
# RCAIDE/Framework/Analyses/Aeroacoustics/Physics_Based.py
#
#
# Created: Jul 2023, M. Clarke
# Modified: Oct 2024, A. Molloy
# ----------------------------------------------------------------------------------------------------------------------
# IMPORT
# ----------------------------------------------------------------------------------------------------------------------
# RCAIDE Imports
import RCAIDE
from RCAIDE.Library.Methods.Aeroacoustics.Common.decibel_arithmetic import SPL_arithmetic
from RCAIDE.Library.Methods.Aeroacoustics.Common.generate_hemisphere_microphone_locations import generate_hemisphere_microphone_locations
from RCAIDE.Library.Methods.Aeroacoustics.Physics_Based_Frequency_Domain.Rotor.compute_rotor_noise import compute_rotor_noise
from .Aeroacoustics import Aeroacoustics
# package imports
import numpy as np
# ----------------------------------------------------------------------------------------------------------------------
# Physics_Based
# ----------------------------------------------------------------------------------------------------------------------
[docs]
class Physics_Based_Frequency_Domain(Aeroacoustics):
"""This is an acoustic analysis based on a collection of frequency domain methods
Assumptions:
Source:
N/A
Inputs:
None
Outputs:
None
Properties Used:
N/A
"""
def __defaults__(self):
""" This sets the default values for the analysis.
Assumptions:
Ground microphone angles start in front of the aircraft (0 deg) and sweep in a lateral direction
to the starboard wing and around to the tail (180 deg)
Source:
N/A
Inputs:
None
Output:
None
Properties Used:
N/A
"""
# Initialize quantities
self.tag = "Physics_Based"
self.method = "Frequency_Domain_Buildup"
self.settings.fidelity = 'line_source'
self.settings.use_plane_loading_surrogate = True
self.settings.wing_wake_interactional_dB_adjustment = 15
[docs]
def evaluate_aeroacoustics(self,segment, vehicle):
""" Process vehicle to setup vehicle, condititon and configuration
Assumptions:
None
Source:
N/4
Inputs:
self.settings.
center_frequencies - 1/3 octave band frequencies [unitless]
Outputs:
None
Properties Used:
self.vehicle
"""
# unpack
settings = self.settings
conditions = segment.state.conditions
dim_cf = len(settings.center_frequencies )
ctrl_pts = int(segment.state.numerics.number_of_control_points)
microphone_locations = generate_hemisphere_microphone_locations(settings)
N_hemisphere_mics = len(microphone_locations)
# create empty arrays for results
total_SPL_dBA = np.ones((ctrl_pts,N_hemisphere_mics))*1E-16
total_SPL_spectra = np.ones((ctrl_pts,N_hemisphere_mics,dim_cf))*1E-16
# iterate through sources and iteratively add rotor noise
rotor_tag = None
i = 0
for network in vehicle.networks:
for propulsor in network.propulsors:
if propulsor.active == True:
for sub_tag , sub_item in propulsor.items():
if isinstance(sub_item, RCAIDE.Library.Components.Powertrain.Converters.Rotor):
rotor_tag = compute_rotor_noise(microphone_locations,sub_item,segment,settings, rotor_index = i, previous_rotor_tag= rotor_tag, identical_propulsors=network.identical_propulsors)
total_SPL_dBA = SPL_arithmetic(np.concatenate((total_SPL_dBA[:,None,:],conditions.aeroacoustics.converters[sub_item.tag].SPL_dBA[:,None,:]),axis =1),sum_axis=1)
total_SPL_spectra = SPL_arithmetic(np.concatenate((total_SPL_spectra[:,None,:,:],conditions.aeroacoustics.converters[sub_item.tag].SPL_1_3_spectrum[:,None,:,:]),axis =1),sum_axis=1)
i += 1
conditions.aeroacoustics.hemisphere_SPL_dBA = (total_SPL_dBA) * (1 - settings.noise_reduction_factors.SPL_dbA)
conditions.aeroacoustics.hemisphere_SPL_1_3_spectrum_dBA = (total_SPL_spectra) * (1 - settings.noise_reduction_factors.SPL_dbA)
return
