Innovation in Noise Mapping in Natural Gas Compressor Stations

2010 ◽  
Author(s):  
K. K. Botros ◽  
A. Hawryluk ◽  
J. Geerligs ◽  
B. Huynh ◽  
R. Phernambucq
Keyword(s):  
Sound Pressure Level ◽  
Gas Turbines ◽  
Sound Pressure ◽  
Dominant Frequency ◽  
Pressure Level ◽  
Multiple Point ◽  
Noise Sources ◽  
Noise Mapping ◽  
Noise Measurements ◽  
Future Work

Noise is generated at gas turbine-based compressor stations from a number of sources, including turbomachinery (gas turbines and compressors), airflow through inlet ducts and scrubbers, exhaust stacks, aerial coolers, and auxiliary systems. Understanding these noise sources is necessary to ensure that the working conditions on site are safe and that the audible noise at neighbouring properties is acceptable. Each noise source has different frequency content, and the overall sound pressure level (OSPL) at any location in the station yard or inside the compressor building is the result of a superposition of these noise sources. This paper presents results of multiple-point spectral noise measurements at three of TransCanada’s compressor stations on the Alberta System. A method is described to determine the overall noise map of the station yard using Delaunay Triangulation and Natural-Neighbour Interpolation techniques. The results are presented in OSPL maps, as well as animated pictures of the sound pressure level (SPL) in frequency domain which will be shown on a video at the conference. The latter will be useful in future work to determine the culprit sources and the respective dominant frequency range that contributes the most to the OSPL.

scholarly journals Pengujian Alat Pemanen Energi Akustik Berbasis Loudspeaker Dengan Sumber Kebisingan Acak Dari Mesin Kendaraan Bermotor

2019 ◽  
Vol 4 ◽  
pp. 152
Author(s):  
Untung Adi Santosa ◽  
Ikhsan Setiawan ◽  
B.S. Utomo
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Random Noise ◽  
Electrical Power ◽  
Dominant Frequency ◽  
Pressure Level ◽  
Acoustic Energy ◽  
Noise Sources ◽  
Quarter Wavelength ◽  
The Impact

<p class="AbstractEnglish"><strong>Abstract: </strong>This paper reports the test results of a loudspeaker-based acoustic energy harvester with acoustic random noise sources from a motorcycle. The harvester consists of a quarter wavelength resonator and a subwoofer type loudspeaker with a nominal diameter of 6 inches. The motorcycle used in this experiment is 135 cc Bajaj Pulsar motorsport with modified exhaust from the GBS-Motosport Jakarta. The motor engine is operated at 3000 rpm, resulting in noise with a fluctuating Sound Pressure Level (SPL) in the range of (90-93) dB. Six variations of resonator lengths are used, those are 21 cm, 31 cm, 58 cm, 85 cm, 112 cm, and 139 cm. In this test, data of dominant frequency, SPL, and output rms voltage were taken for 15 minutes. The rms voltage is measured at 100 Ω load resistor. The results show that the 112 cm resonator produces the highest average rms electrical power, that is (0.21 ± 0.01) mW, which is obtained at frequency that fluctuates within (95-120) Hz. In addition, with random sound sources, SPL and its dominant frequency fluctuate greatly, so it will greatly affect the generated electric power. Further research is needed to enhance the output electrical power and anticipate the impact of frequency fluctuation which exists in random noise sources.</p><p class="AbstractEnglish"><strong>Abstrak: </strong>Paper ini memaparkan hasil pengujian alat pemanen energi akustik berbasis <em>loudspeaker </em>dengan sumber kebisingan acak dari mesin kendaraan bermotor. Alat pemanen energi akustik ini terdiri dari resonator seperempat panjang gelombang dan <em>loudspeaker</em> jenis <em>subwoofer</em> dengan diameter nominal 6 inci. Sumber kebisingan yang digunakan adalah motor Bajaj Pulsar 135 cc dengan knalpot modifikasi dari GBS-Motosport Jakarta. Mesin motor dioperasikan pada laju putaran tetap 3000 rpm, sehingga menghasilkan kebisingan dengan <em>SPL</em> (<em>sound pressure level</em>) yang berfluktuasi dalam interval (90-93) dB. Digunakan enam variasi panjang resonator, yaitu 21 cm, 31 cm, 58 cm, 85 cm, 112 cm, dan 139 cm. Dalam pengujian ini, data frekuensi dominan kebisingan, <em>SPL</em> kebisingan, dan tegangan keluaran alat pemanen energi akustik diambil selama 15 menit. Tegangan <em>rms</em> keluaran diukur pada resistor beban 100 Ω. Hasil eksperimen menunjukkan bahwa resonator dengan panjang 112 cm menghasilkan daya listrik <em>rms</em> rata-rata tertinggi yaitu sebesar (0,21 ± 0,01) mW, diperoleh pada frekuensi yang berfluktuasi antara 95 Hz sampai 120 Hz. Selain itu, hasil eksperimen ini menunjukkan bahwa dengan sumber bunyi acak, <em>SPL</em> kebisingan dan frekuensi dominannya sangat berfluktuasi, sehingga akan sangat berpengaruh terhadap daya listrik yang dihasilkan. Penelitian lebih lanjut diperlukan untuk meningkatkan daya listrik keluaran dan mengantisipasi dampak fluktuasi frekuensi sumber kebisingan acak.</p>

scholarly journals Reducing the harmful effects of noise on the human environment. Sound insulation of industrial skeleton enclosures in the 10–40 kHz frequency range

2020 ◽  
Vol 18 (2) ◽  
pp. 1451-1463
Author(s):  
Witold Mikulski
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Sheet Steel ◽  
Pressure Level ◽  
Sound Insulation ◽  
Frequency Range ◽  
Noise Sources ◽  
Human Environment ◽  
Absorbing Material ◽  
Acoustic Enclosures

Abstract Purpose The purpose of the research is to work out a method for determining the sound insulation of acoustic enclosures for industrial sources emitting noise in the frequency range of 10–40 kHz and apply the method to measure the sound insulation of acoustic enclosures build of different materials. Methods The method is developed by appropriate adaptation of techniques applicable currently for sound frequencies of up to 10 kHz. The sound insulation of example enclosures is determined with the use of this newly developed method. Results The research results indicate that enclosures (made of polycarbonate, plexiglass, sheet aluminium, sheet steel, plywood, and composite materials) enable reducing the sound pressure level in the environment for the frequency of 10 kHz by 19–25 dB with the reduction increasing to 40–48 dB for the frequency of 40 Hz. The sound insulation of acoustic enclosures with a sound-absorbing material inside reaches about 38 dB for the frequency of 10 kHz and about 63 dB for the frequency of 40 kHz. Conclusion Some pieces of equipment installed in the work environment are sources of noise emitted in the 10–40 kHz frequency range with the intensity which can be high enough to be harmful to humans. The most effective technical reduction of the associated risks are acoustic enclosures for such noise sources. The sound pressure level reduction obtained after provision of an enclosure depends on its design (shape, size, material, and thickness of walls) and the noise source frequency spectrum. Realistically available noise reduction values may exceed 60 dB.

scholarly journals Identification and analysis of noise sources in the Noor-Abad gas compressor station, Iran

2015 ◽  
Vol 4 (1) ◽  
pp. 196
Author(s):  
Nader Mohammadi ◽  
Kami Mohammadi
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Acoustic Noise ◽  
Noise Pollution ◽  
Residential Area ◽  
Pressure Level ◽  
Compressor Station ◽  
Noise Condition ◽  
Noise Sources ◽  
Noise Map

The objective of this study is to identify the sources of acoustic noise (noise pollution) in the Noor-Abad gas compressor station and then to prioritize the station equipment based on noise pollution. First, the key locations inside the station as well as in the surrounding residential area, aka the study area, are determined for the measurement of sound pressure level. Then, the sound pressure level is measured at those points, and the related noise map is produced. Based on the noise map, the noise condition in the study area is evaluated by comparing the measured acoustic parameters with allowable standard values. Dangerous regions and critical points are thus identified. The major noise sources consist of main blowdown, units’ blowdowns, scrubbers, and turbo-compressors. The sound pressure level of main blowdown is measured at two intervals from its position: 80 m inside the station and 600 m outside the station (at the edge of the surrounding residential area). Also, the sound pressure level for a unit blowdown and a scrubber is measured at respectively 25 m and 40 m from their positions. Finally, the station equipment is prioritized based on noise pollution. The analysis of measurement results showed that the main noise sources are, respectively, the station main blowdown, units’ scrubbers, units’ blowdowns, turbo-compressors, and gas pipelines.

On the Performance of Porous Sound Absorbent Ceramic Lining in a Combustion Chamber Test Rig

2013 ◽  
Author(s):  
Hans-Christoph Ries ◽  
Mateus Vieira Carlesso ◽  
Christian Eigenbrod ◽  
Stephen Kroll ◽  
Kurosch Rezwan
Keyword(s):  
Combustion Chamber ◽  
Sound Pressure Level ◽  
Gas Turbines ◽  
Sound Pressure ◽  
Porous Ceramic ◽  
Pressure Level ◽  
Test Rig ◽  
Resonance Frequencies ◽  
Lean Premixed ◽  
Ceramic Lining

This paper discusses the potential of using porous ceramic lining as insulating material in combustion chambers with respect to their sound absorbent ability to suppress thermoacoustic instabilities. For this purpose a combustion chamber test rig was developed and different types of ceramic linings were tested. The examined range of power was between 40 and 250 kW and the air-propane equivalence ratio was between 1.2 and 2.0. The overall sound pressure level and frequency domain of a lean premixed swirl stabilized and piloted burner are presented. The resonance frequencies and sound pressure levels are obtained and compared for the different combustion chamber linings. The results show a significant decrease in overall sound pressure level by up to 23.5 dB for sound absorbent lining in comparison to the common sound reflecting combustion chamber lining. In summary, sound absorbent ceramic combustion chamber lining can contribute to improve the stability of lean premixed gas turbines.

Reducing of the Sound Pressure Level in Industrial Areas by Screening Noise Sources

2012 ◽  
Vol 43 (10) ◽  
pp. 28-36
Author(s):  
Tomozei Claudia ◽  
Nedeff Valentin ◽  
Lazar Gabriel ◽  
Ciobanu Elena
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Sources ◽  
Industrial Areas

Study on acoustic environment of canteens in South China University of Technology

2021 ◽  
Vol 263 (5) ◽  
pp. 1695-1702
Author(s):  
Ziyu Zhou ◽  
Hongwei Wang
Keyword(s):  
South China ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Sources ◽  
Acoustic Environment ◽  
University Of Technology ◽  
Different Types ◽  
Satisfaction Evaluation ◽  
The Voice

In order to understand the characteristics of the acoustic environment of University canteens, the canteens of South China University of Technology were selected as the research objects, and the acoustic parameters were measured on the spot and the questionnaire survey was conducted. The results show that the average sound pressure level of restaurants with smaller area is lower than that of restaurants with larger area, and the sound pressure level of dining space first increases rapidly, then increases slowly, and finally remains unchanged with the increase of the number of diners. In the aspect of restaurant acoustic environment satisfaction evaluation, the space with the smallest dining area has the highest acoustic environment satisfaction evaluation level, and the collision sound of tableware collection and table and chair moving has the highest correlation with the acoustic environment satisfaction evaluation. In terms of different types of noise sources, diners think that the most disturbing noise for conversation is the voice of the surrounding people, followed by the collision of tables and chairs and the collection of tableware, and the least disturbing noise is the noise of air conditioning and kitchen equipment.

Single-Stream Jet Noise Prediction Using Empirical Methodology for a Newly Designed Turbojet Engine

2013 ◽  
Author(s):  
João Roberto Barbosa ◽  
Daniel Jonas Dezan
Keyword(s):  
Sound Pressure Level ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Sound Pressure ◽  
Jet Noise ◽  
Pressure Level ◽  
High Fidelity ◽  
Noise Prediction ◽  
Single Stream ◽  
Turbojet Engine

The Center for Reference on Gas Turbines (CRTG), at the Technological Institute of Aeronautics, carries out research in relevant areas of gas turbines, to provide the support for teaching and the ability to design high performance gas turbines. Noise prediction, by means of theoretical and empirical methods, is among such areas. Emphasis is given to the prediction of noise from new engines, to anticipate problems at very early design stage and to take the necessary actions to guarantee that the engine noise is below the recommended limits. Noise prediction is part of a high fidelity gas turbine performance prediction computer program, which provides the designer, at any time during the design phases, with information on the noise levels generated by each component and by the engine. This paper presents results obtained with such methodology incorporated to the high fidelity engine performance prediction computer code, and in the format usually used in the literature. The SPL — far-field one-third octave band sound pressure level — and the OASPL — overall sound pressure level — for single-stream jet were calculated for several engine rotational speeds and observer positions. Two methods have been for the single-stream jet noise prediction, namely: ESDU item 98019 and SAE ARP 876D. Nozzle details were taken from a 5 kN turbojet engine, designed at the CRTG, and which is being installed in the test rig for the preliminary evaluation. In this paper the influence of the observer position on the calculated SPL is presented, and the corresponding OASPL for steady engine operation, combined with the effect of the engine rotational speeds on exhaust jet noise. It is shown that they are in agreement with the noise of similar operating conditions. Ground reflection and atmospheric attenuation were not considered in this work. The results indicate that the noise prediction is adequate for use during the design phase and that the model derived in the SAE ARP 876D paper provides better single-stream jet noise prediction than ones predicted using the ESDU Item 98019.

Experimental Study on a Notched Nozzle for Jet Noise Reduction

2011 ◽  
Author(s):  
T. Ishii ◽  
H. Oinuma ◽  
K. Nagai ◽  
N. Tanaka ◽  
Y. Oba ◽  
...  
Keyword(s):  
Experimental Study ◽  
Noise Reduction ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Mixing Layer ◽  
Jet Noise ◽  
Computational Prediction ◽  
Pressure Level ◽  
Far Field ◽  
Noise Sources

This paper describes an experimental study on a notched nozzle for jet noise reduction. The notch, a tiny tetrahedral dent formed at the edge of a nozzle, is expected to enhance mixing within a limited region downstream of the nozzle. The enhanced mixing leads to the suppression of broadband peak components of jet noise with little effect on the engine performance. To investigate the noise reduction performances of a six-notch nozzle, a series of experiments have been performed at an outdoor test site. Tests on the engine include acoustic measurement in the far field to evaluate the noise reduction level with and without the notched nozzle, and pressure measurement near the jet plume to obtain information on noise sources. The far-field measurement indicated the noise reduction by as much as 3 dB in terms of overall sound pressure level in the rear direction of the engine. The use of the six-notch nozzle though decreased the noise-benefit in the side direction. Experimental data indicate that the high-frequency components deteriorate the noise reduction performance at wider angles of radiation. Although the increase in noise is partly because of the increase in velocity, the penetration of the notches into the jet plume is attributed to the increase in sound pressure level in higher frequencies. The results of near-field measurement suggest that an additional sound source appears up to x/D = 4 due to the notches. In addition, the total pressure maps downstream of the nozzle edge, obtained using a pressure rake, show that the notched nozzle deforms the shape of the mixing layer, causing it to become wavy within a limited distance from the nozzle. This deformation of the mixing layer implies strong vortex shedding and thus additional noise sources. To improve the noise characteristics, we proposed a revised version of the nozzle on the basis of a computational prediction, which contained 18 notches that were smaller than those in the 6-notched nozzle. Ongoing tests indicate greater noise reduction in agreement with the computational prediction.

Effects of Leisure Activity Related Noise in Residential Zones

2005 ◽  
Vol 12 (4) ◽  
pp. 265-276 ◽  
Author(s):  
J.M. Barrigón Morillas ◽  
V. Gómez Escobar ◽  
J.A. Méndez Sierra ◽  
R. Vílchez-Gómez ◽  
J.M. Vaquero
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Leisure Activity ◽  
Pressure Level ◽  
Noise Sources ◽  
Sound Levels ◽  
The City

An analysis of two noise surveys of the city of Cáceres is presented. The first was made for 400 inhabitants living throughout the city, and the second for 50 inhabitants of a conflictive zone due to noise during the night, mainly at weekends. The similarity of the two groups of persons interviewed was studied and verified. Then a comparison was made of the responses referring to disturbing noise sources and effects of noise. The results showed appreciable differences between the two surveys. Some continuous sound pressure level measurements made over several days are also presented. They show major differences in the sound levels between the zone and the rest of the city.

Mesa Verde National Park: Acoustic monitoring report

2021 ◽  
Author(s):  
Jacob Job
Keyword(s):  
Sound Pressure Level ◽  
National Park ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Logarithmic Scale ◽  
Noise Sources ◽  
Mesa Verde ◽  
Sound Levels ◽  
Human Ear

In 2015, the Natural Sounds and Night Skies Division (NSNSD) received a request to collect baseline acoustical data at Mesa Verde National Park (MEVE). Between July and August 2015, as well as February and March 2016, three acoustical monitoring systems were deployed throughout the park, however one site (MEVE002) stopped recording after a couple days during the summer due to wildlife interference. The goal of the study was to establish a baseline soundscape inventory of backcountry and frontcountry sites within the park. This inventory will be used to establish indicators and thresholds of soundscape quality that will support the park and NSNSD in developing a comprehensive approach to protecting the acoustic environment through soundscape management planning. Additionally, results of this study will help the park identify major sources of noise within the park, as well as provide a baseline understanding of the acoustical environment as a whole for use in potential future comparative studies. In this deployment, sound pressure level (SPL) was measured continuously every second by a calibrated sound level meter. Other equipment included an anemometer to collect wind speed and a digital audio recorder collecting continuous recordings to document sound sources. In this document, “sound pressure level” refers to broadband (12.5 Hz–20 kHz), A-weighted, 1-second time averaged sound level (LAeq, 1s), and hereafter referred to as “sound level.” Sound levels are measured on a logarithmic scale relative to the reference sound pressure for atmospheric sources, 20 μPa. The logarithmic scale is a useful way to express the wide range of sound pressures perceived by the human ear. Sound levels are reported in decibels (dB). A-weighting is applied to sound levels in order to account for the response of the human ear (Harris, 1998). To approximate human hearing sensitivity, A-weighting discounts sounds below 1 kHz and above 6 kHz. Trained technicians calculated time audible metrics after monitoring was complete. See Methods section for protocol details, equipment specifications, and metric calculations. Median existing (LA50) and natural ambient (LAnat) metrics are also reported for daytime (7:00–19:00) and nighttime (19:00–7:00). Prominent noise sources at the two backcountry sites (MEVE001 and MEVE002) included vehicles and aircraft, while building and vehicle predominated at the frontcountry site (MEVE003). Table 1 displays time audible values for each of these noise sources during the monitoring period, as well as ambient sound levels. In determining the current conditions of an acoustical environment, it is informative to examine how often sound levels exceed certain values. Table 2 reports the percent of time that measured levels at the three monitoring locations were above four key values.

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