# RCAIDE/Framework/Analyses/Noise/Correlation_Buildup.py
#
#
# Created: Jul 2023, M. Clarke
# ----------------------------------------------------------------------------------------------------------------------
# IMPORT
# ----------------------------------------------------------------------------------------------------------------------
# RCAIDE Imports
import RCAIDE
from RCAIDE.Library.Methods.Noise.Correlation_Buildup.Airframe.airframe_noise import airframe_noise
from RCAIDE.Library.Methods.Noise.Correlation_Buildup.Turbofan.turbofan_engine_noise import turbofan_engine_noise
from RCAIDE.Library.Methods.Noise.Common.decibel_arithmetic import SPL_arithmetic
from RCAIDE.Library.Methods.Noise.Common.generate_hemisphere_microphone_locations import generate_hemisphere_microphone_locations
from .Noise import Noise
# package imports
import numpy as np
# ----------------------------------------------------------------------------------------------------------------------
# Correlation_Buildup
# ----------------------------------------------------------------------------------------------------------------------
[docs]
class Correlation_Buildup(Noise):
"""This is an acoustic analysis based on a collection of correlative modes
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 = "Correlation_Buildup"
self.settings.noise_hemisphere_radius = 50
return
[docs]
def evaluate_noise(self,segment):
""" Process vehicle to setup geometry, condititon and configuration
Assumptions:
None
Source:
N/4
Inputs:
self.settings.
center_frequencies - 1/3 octave band frequencies [unitless]
Outputs:
None
Properties Used:
"""
# unpack
config = segment.analyses.noise.vehicle
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
airframe_noise_res = airframe_noise(microphone_locations,segment,config,settings)
total_SPL_dBA = SPL_arithmetic(np.concatenate((total_SPL_dBA[:,None,:],airframe_noise_res.SPL_dBA[:,None,:]),axis =1),sum_axis=1)
total_SPL_spectra[:,:,5:] = SPL_arithmetic(np.concatenate((total_SPL_spectra[:,None,:,5:],airframe_noise_res.SPL_1_3_spectrum[:,None,:,:]),axis =1),sum_axis=1)
# iterate through sources
for network in config.networks:
for propulsor in network.propulsors:
if type(propulsor) == RCAIDE.Library.Components.Powertrain.Propulsors.Turbofan:
engine_noise = turbofan_engine_noise(microphone_locations,propulsor,conditions.noise.propulsors[propulsor.tag],segment,settings)
total_SPL_dBA = SPL_arithmetic(np.concatenate((total_SPL_dBA[:,None,:],engine_noise.SPL_dBA[:,None,:]),axis =1),sum_axis=1)
total_SPL_spectra[:,:,5:] = SPL_arithmetic(np.concatenate((total_SPL_spectra[:,None,:,5:],engine_noise.SPL_1_3_spectrum[:,None,:,:]),axis =1),sum_axis=1)
conditions.noise.hemisphere_SPL_dBA = total_SPL_dBA * (1 - settings.noise_reduction_factors.SPL_dbA)
conditions.noise.hemisphere_SPL_1_3_spectrum_dBA = total_SPL_spectra * (1 - settings.noise_reduction_factors.SPL_dbA)
return
