Mapping Heavy Vehicle Noise Source Heights for Highway Noise

2018 ◽  
Vol 2672 (24) ◽  
pp. 134-143 ◽  
Author(s):  
Carrie Janello ◽  
Paul R. Donavan
Keyword(s):  
North Carolina ◽  
Noise Source ◽  
Operating Conditions ◽  
Heavy Vehicle ◽  
Secondary Source ◽  
Noise Sources ◽  
Vehicle Noise ◽  
Heavy Trucks ◽  
Heavy Truck ◽  
Pavement Noise

The NCHRP Project 25-45 was initiated in 2013 to measure noise sources during heavy truck pass-bys using the acoustic beamforming method. Phase I testing included measurements from four relatively flat sites in Northern California, where heavy trucks traveled under moderate vehicle speeds. Sixteen additional sites in North Carolina were tested as part of Phase II. These sites had varying pavement grades, faster/slower posted speed limits, and varying operating conditions. The source mapping results from both phases were used to develop noise versus height profiles. The profiles were not significantly dependent on site and operating conditions. Average profiles were developed for each site to demonstrate that the predominant noise source was tire/pavement noise, with engine/powertrain being the secondary source; elevated sources occurred rarely and were equal to or greater than tire/pavement for only 0.5% of the total 1,289 trucks measured, while only 1.8% were within 5 dB(A) of the pavement source and 4.7% were within 10 dB(A).

Mapping Heavy Vehicle Noise Source Heights for Highway Noise Analysis

2017 ◽  
Author(s):  
Paul R. Donavan and Carrie J. Janello ◽  
◽  
◽  
Keyword(s):  
Noise Source ◽  
Noise Analysis ◽  
Heavy Vehicle ◽  
Vehicle Noise ◽  
Highway Noise

Identification of the Vehicle Noise Source by Sound Intensity Method

2011 ◽  
Vol 346 ◽  
pp. 634-638 ◽  
Author(s):  
He Li ◽  
Qing Rong Zhao ◽  
Bang Chun Wen
Keyword(s):  
Power Spectrum ◽  
Noise Source ◽  
Sound Intensity ◽  
Regulation System ◽  
Sound Power ◽  
Analysis Software ◽  
Noise Sources ◽  
Vehicle Noise ◽  
Measurement Results ◽  
Radiation Noise

In this paper, we analysed the level of radiation noise and distribution of noise sources of car’s engine and front panels by using sound intensity method. To get the nephogram of sound intensity and sound power spectrum, we used the sound intensity probe and Multi-channel Data Acquisition Regulation System B&K 3560-D and Pulse Data Processing Analysis Software. By analysing experimental results, we can conclude the location of noise sources of these parts. The measurement results will serve as a reference for the car noise reduction.

Noise Reduction for a Given Vehicle Based on Sound Intensity Measurement Method

2012 ◽  
Vol 503-504 ◽  
pp. 1212-1215
Author(s):  
Zhi Xin Liu ◽  
Yong Wan Shi
Keyword(s):  
Noise Source ◽  
Sound Intensity ◽  
Operating Conditions ◽  
Engineering Practice ◽  
Noise Generation ◽  
Vibration Signals ◽  
Vehicle Noise ◽  
Noise Source Identification ◽  
Radiation Noise ◽  
Reliable Basis

In this paper the mechanisms of the bottom radiant noise generation of a given mini vehicle was investigated and the corresponding countermeasures were put forward in reducing the noise of a diesel engine. According to the analysis of acoustic signals and vibration signals measurement, an investigation of the noise source identification in a given vehicle was presented. With the sound intensity method, the major sources of the bottom radiation noise of the engine under three operating conditions were surveyed. The research provides the reliable basis for the engineering practice to reduce vehicle noise level.

scholarly journals Analysis on the Noise for the Different Gearboxes of the Heavy Truck

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Zhixian Zhong ◽  
Zhansi Jiang ◽  
Yuhong Long ◽  
Xin Zhan
Keyword(s):  
Peak Frequency ◽  
Helical Gear ◽  
Speed Ratio ◽  
Heavy Vehicle ◽  
Vehicle Noise ◽  
Gear Noise ◽  
Limit Value ◽  
Noise Frequency ◽  
Heavy Truck ◽  
Excessive Noise

In order to locate the excessive noise caused by gearbox noise when a heavy vehicle is accelerating, the noise and vibration on the key parts of the gearbox were tested and analyzed, and the peak noise frequency of radiating from the subbox of gearbox was found, which is the same as the peak frequency of pass-by noise. Aiming at the larger gear noise of the gearbox subbox, the experiments of pass-by noise by the two ways of the different speed-ratio gearbox, and the transformation of vice-box with helical gear, the pass-by noise was reduced by 5.6 and 3.9 dB(A), and it was made to reach the less GB limit-value. Meanwhile, the effect of the different-ratio gearbox on the vehicle noise was analyzed. So, the methods provide a practical basis for the vehicle noise and the fault diagnosis of gearbox.

Quantification of aerodynamically induced noise and vibration-induced noise in a suction unit

2011 ◽  
Vol 225 (3) ◽  
pp. 617-624 ◽  
Author(s):  
J Prezelj ◽  
M Čudina
Keyword(s):  
Transfer Function ◽  
Noise Reduction ◽  
Noise Source ◽  
Operating Conditions ◽  
Frequency Range ◽  
Centrifugal Blower ◽  
Noise Sources ◽  
Noise And Vibration ◽  
Different Types ◽  
The Individual

Noise, generated by a centrifugal blower, can be divided according to its origin, into aerodynamically induced noise and vibration-induced noise. The contribution of the individual noise source to the total emitted noise is hard to determine, but it is crucial for the design of noise reduction measures. In order to reduce the noise of the centrifugal blower in a broad range of operating conditions, an identification of noise sources needs to be performed. An analysis of the most important noise origin in a centrifugal blower presented in this article was performed by measurements of the transfer function between noise and vibration, under different types of excitation. From the analyses one can conclude that the dominant noise source of a centrifugal blower can be attributed to the aerodynamically generated noise which exceeds the vibration-induced noise for more than 10 dB in a broad frequency range.

scholarly journals A System-Level Modelling of Noise in Coupled Resonating MEMS Sensors

2020 ◽  
Vol 3 (1) ◽  
pp. 5
Author(s):  
Vinayak Pachkawade
Keyword(s):  
Noise Source ◽  
Operating Conditions ◽  
Sensor System ◽  
System Level ◽  
Mems Sensors ◽  
Noise Sources ◽  
System A ◽  
Sensing Applications ◽  
Mechanical Noise ◽  
The Impact

This paper presents realistic system-level modeling of effective noise sources in a coupled resonating mode-localized MEMS sensors. A governing set of differential equations are used to build a numerical model of a mechanical noise source in a coupled-resonator sensor and an effective thermo-mechanical noise is quantified through the simulation performed via SIMULINK. On a similar note, an effective noise that stems from the electronic readout used for the coupled resonating MEMS sensors is also quantified. Various noise sources in electronic readout are identified and the contribution of each is quantified. A comparison between an effective mechanical and electronic noise in a sensor system aids in identifying the dominant noise source in a sensor system. A method to optimize the system noise floor for an amplitude-based readout is presented. The proposed models present a variety of operating conditions, such as finite quality factor, varying coupled electrostatic spring strength, and operation with in-phase and out-of-phase mode. The proposed models aim to study the impact of fundamental noise processes that govern the ultimate resolution into a coupled resonating system used for various sensing applications.

Identification of Noise Sources on a Diesel Engine Using Sound Intensity Measurements

2011 ◽  
Vol 268-270 ◽  
pp. 205-209
Author(s):  
Bao Cheng Zhang ◽  
Peng Fei Zhao ◽  
Bao Ji Li
Keyword(s):  
Noise Level ◽  
Noise Source ◽  
Sound Intensity ◽  
Engineering Practice ◽  
Noise Sources ◽  
Vehicle Noise ◽  
Intensity Measurements ◽  
Noise Source Identification ◽  
Radiation Noise ◽  
Reliable Basis

According to the analysis of acoustic signals and vibration signals measurement, an investigation of the noise source identification in a diesel is presented, and the noise level of the diesel is comprehended. With the sound Intensity method, the major sources of the exterior radiation noise of the engine are surveyed. The research provides the reliable basis for the engineering practice to reduce the vehicle noise level.

Noise source location and scaling of subsonic upper-surface blowing

2020 ◽  
Vol 19 (3-5) ◽  
pp. 191-206
Author(s):  
Trae L Jennette ◽  
Krish K Ahuja
Keyword(s):  
Strouhal Number ◽  
Noise Source ◽  
Low Frequency ◽  
Directivity Pattern ◽  
Source Location ◽  
Dipole Source ◽  
Frequency Noise ◽  
Noise Sources ◽  
Trailing Edge ◽  
Trailing Edge Noise

This paper deals with the topic of upper surface blowing noise. Using a model-scale rectangular nozzle of an aspect ratio of 10 and a sharp trailing edge, detailed noise contours were acquired with and without a subsonic jet blowing over a flat surface to determine the noise source location as a function of frequency. Additionally, velocity scaling of the upper surface blowing noise was carried out. It was found that the upper surface blowing increases the noise significantly. This is a result of both the trailing edge noise and turbulence downstream of the trailing edge, referred to as wake noise in the paper. It was found that low-frequency noise with a peak Strouhal number of 0.02 originates from the trailing edge whereas the high-frequency noise with the peak in the vicinity of Strouhal number of 0.2 originates near the nozzle exit. Low frequency (low Strouhal number) follows a velocity scaling corresponding to a dipole source where as the high Strouhal numbers as quadrupole sources. The culmination of these two effects is a cardioid-shaped directivity pattern. On the shielded side, the most dominant noise sources were at the trailing edge and in the near wake. The trailing edge mounting geometry also created anomalous acoustic diffraction indicating that not only is the geometry of the edge itself important, but also all geometry near the trailing edge.

scholarly journals Innovative techniques for the improvement of industrial noise sources identification by beamforming

Noise Mapping ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 129-137
Author(s):  
Giorgio Baldinelli ◽  
Francesco Bianchi ◽  
Danilo Costarelli ◽  
Francesco D’Alessandro ◽  
Flavio Scrucca ◽  
...  
Keyword(s):  
Image Processing ◽  
Noise Source ◽  
Focal Length ◽  
Noise Sources ◽  
Geometric Information ◽  
Industrial Noise ◽  
Sources Identification ◽  
Innovative Technique ◽  
Innovative Techniques

Abstract An innovative technique based on beamforming is implemented, at the aim of detecting the distances from the observer and the relative positions among the noise sources themselves in multisource noise scenarios. By means of preliminary activities to assess the optical camera focal length and stereoscopic measurements followed by image processing, the geometric information in the source-microphone direction is retrieved, a parameter generally missed in classic beamforming applications. A corollary of the method consists of the possibility of obtaining also the distance among different noise sources which could be present in a multisource environment. A loss of precision is found when the effect of the high acoustic reflectivity ground interferes with the noise source.

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