Aero-Acoustic Noise Measurement of Vehicle Using Surface Microphone in Wind Tunnel

2005 ◽  
Author(s):  
Masaki Tuchiya ◽  
Tsuyoshi Yamashita ◽  
Niels V. B\atgholm ◽  
Toshikazu Satoh ◽  
Masateru Kimura
Keyword(s):  
Wind Tunnel ◽  
Acoustic Noise ◽  
Noise Measurement ◽  
Acoustic Noise Measurement

Field Comparison of IEC 61400-11 Wind Turbines — Part 11: Acoustic Noise Measurement Techniques, Edition 3.0 and Edition 2.1

2015 ◽  
Author(s):  
Rob Jozwiak ◽  
Allan Munro ◽  
Duncan Halstead ◽  
Addie Denison
Keyword(s):  
Wind Turbines ◽  
Acoustic Noise ◽  
Power Level ◽  
Measurement Techniques ◽  
Noise Measurement ◽  
Sound Power ◽  
Measurement Standard ◽  
Detailed Review ◽  
Sound Power Level ◽  
Acoustic Noise Measurement

Following the release of Edition 3.0 (2012) of IEC 61400-11 Wind Turbines – Part 11: Acoustic noise measurement techniques, there has been a lot of interest as to how analysis results differ from methods stipulated in Edition 2.1 (2006). This paper provides a detailed review of the differences between Edition 3.0 and Edition 2.1. An analysis is provided on differences in evaluation of the apparent sound power level and tonal audibility between both versions of the measurement standard.

Acoustic noise measurement in counter-rotating propellers

2019 ◽  
Vol 33 (7) ◽  
pp. 3187-3192
Author(s):  
Pin Liu ◽  
Fumiha Odo ◽  
Tengen Murakami ◽  
Toshiaki Kanemoto
Keyword(s):  
Acoustic Noise ◽  
Noise Measurement ◽  
Acoustic Noise Measurement

scholarly journals Underwater acoustic noise measurement in test tanks

2000 ◽  
Vol 25 (4) ◽  
pp. 516-522 ◽  
Author(s):  
N. Cochard ◽  
J.L. Lacoume ◽  
P. Arzelies ◽  
Y. Gabillet
Keyword(s):  
Acoustic Noise ◽  
Noise Measurement ◽  
Underwater Acoustic ◽  
Acoustic Noise Measurement

Life before and after implementation of an acoustic noise reduction enclosure

2005 ◽  
Vol 109 (1092) ◽  
pp. 65-74
Author(s):  
B. Timmins
Keyword(s):  
Wind Tunnel ◽  
Noise Reduction ◽  
Acoustic Noise ◽  
Financial Health ◽  
Two Phase ◽  
North West ◽  
The North ◽  
Close Proximity ◽  
Before And After ◽  
Increase Productivity

Abstract This paper looks back on the designs and ambitions of ARA in resolving a long term acoustic noise problem which threatened ARA with closure. This paper today briefly looks back to the original issues but deals more fully with the later phases of a two phase project implementation and construction. ARA is now a truly ‘silent site’, where closure was once threatened, ARA has achieved the implementation of a bespoke noise reduction enclosure where 24-hour running has proved to be a reality. This paper looks at the design and construction phases, the ‘before and after’ noise footprints and at some of the financial benefits ARA has achieved. The ARA transonic wind tunnel is sited on an industrial estate on the north west perimeter of Bedford. When it was first built it was on an original farm site with no appreciable residential houses in close proximity. Since the early 1950s there has been considerable residential development around the ARA site resulting in the local householders complaining about the wind tunnel acoustic noise. In early 1999 ARA was obliged to consider several options for noise reduction measures to reduce the noise to within UK government statutory requirements. This paper deals briefly with the original noise nuisance characteristics and footprint, the noise reduction design and method that ARA selected and shows the construction phases, the further noise treatment ARA had to do on other major ancillary equipment to make ARA a truly quiet industrial site. The paper shows how ARA has utilised the resulting benefits of these investments to increase productivity and reduce costs, and the influence it has had on ARA’s financial health.

Low Acoustic Noise and Turbulence (LANT) wind-tunnel at USP-EESC

2018 ◽  
Author(s):  
Juan Carlos Serrano Rico ◽  
Filipe R. Amaral ◽  
Christian Bresci ◽  
Matheus M. Beraldo ◽  
Marcello F. Medeiros
Keyword(s):  
Wind Tunnel ◽  
Acoustic Noise

scholarly journals A Digital Signal Processor Based Acoustic Sensor for Outdoor Noise Monitoring in Smart Cities

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 605 ◽  
Author(s):  
Juan Manuel López ◽  
Jesús Alonso ◽  
César Asensio ◽  
Ignacio Pavón ◽  
Luis Gascó ◽  
...  
Keyword(s):  
Acoustic Noise ◽  
Smart Cities ◽  
Monitoring Network ◽  
Noise Pollution ◽  
Sound Level ◽  
Noise Measurement ◽  
Acoustic Sensor ◽  
Measurement Instruments ◽  
Frequency Weighting

Presently, large cities have significant problems with noise pollution due to human activity. Transportation, economic activities, and leisure activities have an important impact on noise pollution. Acoustic noise monitoring must be done with equipment of high quality. Thus, long-term noise monitoring is a high-cost activity for administrations. For this reason, new alternative technological solutions are being used to reduce the costs of measurement instruments. This article presents a design for a versatile electronic device to measure outdoor noise. This device has been designed according to the technical standards for this type of instrument, which impose strict requirements on both the design and the quality of the device’s measurements. This instrument has been designed under the original equipment manufacturer (OEM) concept, so the microphone–electronics set can be used as a sensor that can be connected to any microprocessor-based device, and therefore can be easily attached to a monitoring network. To validate the instrument’s design, the device has been tested following the regulations of the calibration laboratories for sound level meters (SLM). These tests allowed us to evaluate the behavior of the electronics and the microphone, obtaining different results for these two elements. The results show that the electronics and algorithms implemented fully fit within the requirements of type 1 noise measurement instruments. However, the use of an electret microphone reduces the technical features of the designed instrument, which can only fully fit the requirements of type 2 noise measurement instruments. This situation shows that the microphone is a key element in this kind of instrument and an important element in the overall price. To test the instrument’s quality and show how it can be used for monitoring noise in smart wireless acoustic sensor networks, the designed equipment was connected to a commercial microprocessor board and inserted into the infrastructure of an existing outdoor monitoring network. This allowed us to deploy a low-cost sub-network in the city of Málaga (Spain) to analyze the noise of conflict areas due to high levels of leisure noise. The results obtained with this equipment are also shown. It has been verified that this equipment meets the similar requirements to those obtained for type 2 instruments for measuring outdoor noise. The designed equipment is a two-channel instrument, that simultaneously measures, in real time, 86 sound noise parameters for each channel, such as the equivalent continuous sound level (Leq) (with Z, C, and A frequency weighting), the peak level (with Z, C, and A frequency weighting), the maximum and minimum levels (with Z, C, and A frequency weighting), and the impulse, fast, and slow time weighting; seven percentiles (1%, 5%, 10%, 50%, 90%, 95%, and 99%); as well as continuous equivalent sound pressure levels in the one-third octave and octave frequency bands.

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