Noise reduction of enhanced acoustic balconies on a high-rise building block

2021 ◽  
Vol 263 (1) ◽  
pp. 5327-5334
Author(s):  
SK Tang ◽  
Rudolf YC Lee
Keyword(s):  
Noise Reduction ◽  
Natural Ventilation ◽  
Traffic Noise ◽  
Elevation Angle ◽  
Noise Levels ◽  
Indoor Space ◽  
New Device ◽  
Air Inlet ◽  
The Difference ◽  
The Impact

A new device called 'enhanced acoustic balcony' is installed in a new housing estate in Hong Kong. It is intended to help reduce the impact of traffic noise on the residents. This balcony is basically an enlarged form of a plenum window and with three openings. Apart from the outdoor air inlet, there is the balcony door and a side-hung window on the interior balcony wall for natural ventilation of the indoor space. Sound absorption of NRC 0.7 is installed on the balcony ceiling and its sidewall facing the incoming traffic noise and an inclined panel is installed outside the balcony to provide noise screening. A site measurement of its noise reduction is carried out in the present study in a newly completed housing block. A 28 m long loudspeaker array is used as the sound source. The indoor noise levels are measured according to ISO standard. The results show that the difference between indoor and outdoor noise levels in the presence of this balcony form varies over a relatively narrow range between 10 to 13 dBA for an elevation angle from 25 to 60 deg. There is a weak increase of the noise level difference with elevation angle.

scholarly journals The Impact of Thin Asphalt Layers as a Road Traffic Noise Intervention in an Urban Environment

2021 ◽  
Vol 13 (22) ◽  
pp. 12561
Author(s):  
Ablenya Grangeiro de Barros ◽  
Jarl K. Kampen ◽  
Cedric Vuye
Keyword(s):  
Noise Exposure ◽  
Road Traffic ◽  
Traffic Noise ◽  
Low Noise ◽  
Urban Environments ◽  
Comfort Level ◽  
Road Traffic Noise ◽  
Acoustic Measurements ◽  
Noise Levels ◽  
The Impact

Low-noise thin asphalt layers (TALs) are a feasible solution to mitigate road traffic noise in urban environments. Nevertheless, the impacts of this type of noise intervention are reported mostly regarding noise levels, while non-acoustic aspects influencing the population perception are still little-known. This study investigates the implementation of TALs in two streets of Antwerp, Belgium. The effectiveness of the intervention was measured via noise modelling and acoustic measurements of road traffic noise. A reduction of 2.8 dB in noise exposure was observed in Lden and Lnight, while SPB measurements showed decreases up to 5.2 dB on the roadside. The subjective impacts of the TALs were evaluated via self-administered surveys and compared to results from control streets. The annoyance indicators were positively impacted by the TALs implementation, resulting in annoyance levels similar or lower than in the control streets. The TALs did not impact the reported physical complaints, sleep quality, and comfort level to perform activities.

Characterization of Traffic Noise and Honking Assessment of an Indian Urban Road

2018 ◽  
Vol 17 (04) ◽  
pp. 1850031 ◽  
Author(s):  
Ritesh Vijay ◽  
T. Chakrabarti ◽  
Rajesh Gupta
Keyword(s):  
Traffic Noise ◽  
Traffic Monitoring ◽  
Traffic Volume ◽  
Time Interval ◽  
Highway Traffic ◽  
Noise Levels ◽  
Additional Noise ◽  
Road Width ◽  
The Impact

To study the traffic noise on an Indian urban highway, traffic noise levels (Leq, Lpeak, Lmax and Lmin), traffic volume, speed and honking incidents were measured in peak traffic hours in the morning and evening. An attempt has been made to characterize the traffic noise including the impact of honking. Honking of horn was positively correlated with Leq and negatively correlated with traffic speed. In case of traffic volume and road width, no significant correlation was established with Leq. Based on the observed honking and Leq in each time interval, statistical analysis was performed for assessing the impact of honking on traffic noise and its estimation through trend analysis. Further, quantification of honking noise was carried out considering frequency analysis of audio spectrum of traffic noise. Both the analyzes confirm the honking contributed an additional noise of 1–4[Formula: see text]dB(A) over and above the traffic monitoring noise. The study suggests that honking noise must be included as a factor while monitoring traffic noise in some places where honking is common practice. This study will help in characterizing the traffic noise and the impact of honking for further abatement studies.

A Study of Traffic Noise Reduction Performance of Arc Pavement Roads and Traffic Flow

2006 ◽  
Author(s):  
Zheng Lou ◽  
Liming Dai
Keyword(s):  
Noise Reduction ◽  
Traffic Flow ◽  
Noise Level ◽  
Traffic Noise ◽  
Flow Conditions ◽  
Noise Levels ◽  
Flow Monitoring ◽  
Before And After ◽  
The Relationship ◽  
Rubber Concrete

Asphalt Rubber Concrete (ARC) pavement has shown an excellent performance of noise reduction in terns of reducing the power of air pumping, absorbing sound power, depressing carcass vibration and changing sound reflection geometry. This research is to investigate the traffic noise reduction performance of a segment of test highway with ARC pavement in Saskatchewan, Canada. Before and after the highway section was repaved, a series of traffic noise level measurements combining with traffic flow monitoring are conducted in order to compare the sound performance of ARC and conventional pavements. A relationship between the noise level and corresponding traffic flow conditions of ARC pavement is established. The energetic averaging method is employed to study the relationship between traffic noise level and traffic flow condition. The two noise levels of 24-hour's time averaged and Statistical Pass-By noise levels indicated that the ARC pavement has a better sound performance over that of conventional pavement in terms of traffic noise reduction. The traffic noise reduction applicability of ARC pavement under various traffic flow conditions is also performed in this research.

Road traffic noise impact assessment based on the difference between existing and future traffic noise levels

2004 ◽  
Vol 115 (5) ◽  
pp. 2413-2414
Author(s):  
Chetlur G. Balachandran ◽  
Sandor Juhasz ◽  
Arthur Morrone ◽  
Noemi Castillo
Keyword(s):  
Impact Assessment ◽  
Road Traffic ◽  
Traffic Noise ◽  
Road Traffic Noise ◽  
Noise Levels ◽  
Noise Impact ◽  
The Difference

Assessment of Traffic Noise on Highway Passing from Urban Agglomeration

2014 ◽  
Vol 13 (04) ◽  
pp. 1450031 ◽  
Author(s):  
Ritesh Vijay ◽  
Chandan Kori ◽  
Manoj Kumar ◽  
T. Chakrabarti ◽  
Rajesh Gupta
Keyword(s):  
Traffic Noise ◽  
Noise Pollution ◽  
Traffic Volume ◽  
Urban Agglomeration ◽  
International Standards ◽  
Pollution Level ◽  
Noise Levels ◽  
Noise Abatement ◽  
Road Width ◽  
The Impact

Assessment of traffic noise pollution in developing countries is complex due to heterogeneity in traffic conditions like traffic volume, road width, honking, etc. To analyze the impact of such variables, a research study was carried out on a national highway passing from an urban agglomeration. Traffic volume and noise levels (L10, L min , L max , L eq and L90) were measured during morning and evening peak hours. Contribution of noise by individual vehicle was estimated using passenger car noise unit. Extent of noise pollution and impact of noisy vehicles were estimated using noise pollution level and traffic noise index, respectively. Noise levels were observed to be above the prescribed Indian and International standards. As per audio spectrum analysis of traffic noise, honking contributed an additional 3–4 dB(A) noise. Based on data analysis, a positive relationship was observed between noise levels and honking while negative correlation was observed between noise levels and road width. The study suggests that proper monitoring and analysis of traffic data is required for better planning of noise abatement measures.

Investigation on Air Quality in Strawberry Greenhouse under Natural Ventilation

2014 ◽  
Vol 675-677 ◽  
pp. 382-387
Author(s):  
Wei Hong Fu ◽  
Shi Jun You
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Natural Ventilation ◽  
General Trend ◽  
Environmental Parameters ◽  
Air Velocity ◽  
Indoor Temperature ◽  
Air Inlet ◽  
Simulation And Experiment ◽  
The Impact

The effect of the air inlet and the air outlet of the strawberry greenhouse are very significant to the microclimate in greenhouse under the conditions of natural ventilation. This paper studied the numerical simulation and experiment of indoor temperature field of the strawberry greenhouse with natural ventilation in different areas of air inlet and air outlet. The impact of the natural ventilation on the microclimate of strawberry greenhouse has been explored. The results indicated that the air velocity and temperature in the air inlet effected on the temperature distribution within the greenhouse, and the temperature near the air inlet was susceptible to the outdoor environmental parameters. The general trend of the variation of the indoor temperature in the greenhouse decreased with increasing the sizes of the air inlet and the air outlet. The overall trend of temperature gradient is similar within the greenhouse.

scholarly journals The “sound of silence” in Granada during the COVID-19 lockdown

Noise Mapping ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 16-31 ◽  
Author(s):  
Jerónimo Vida Manzano ◽  
José Antonio Almagro Pastor ◽  
Rafael García Quesada ◽  
Francesco Aletta ◽  
Tin Oberman ◽  
...  
Keyword(s):  
Human Activity ◽  
Road Traffic ◽  
Traffic Noise ◽  
Environmental Noise ◽  
Road Traffic Noise ◽  
Noise Levels ◽  
Noise Sources ◽  
Comparison Results ◽  
The Impact ◽  
The City

Abstract Exceptional circumstances in the city of Granada due to the COVID-19 lockdown have provided the opportunity to characterise the impact of humans on its urban acoustic climate. Traditional environmental noise management and urban sound planning usually take into account noise sources in the city, such as industrial activities or road traffic noise, in model estimations, as well as in empirical research. But trying to isolate human impact by itself, human activity including social activity, walking, talking or just going around the city, has always been a difficult or even impossible task. The COVID-19 lockdown measures have provided the opportunity to study urban climate as never before, affected just by natural or animal noise sources. Previous soundscape research at some iconic sites in the city of Granada carried out in 2019 before the lockdown and a special measuring campaign carried out at the same locations during the lockdown in 2020 offered valuable information on sound levels and local characteristics in order to carry out this comparison. Results show a great change in environmental noise levels that is interesting not only because of its magnitude, but also for its implications, especially at those sites where social human activity was an identifying characteristic. Natural or animal sounds became surprisingly evident at some study sites, especially where road traffic noise dramatically decreased, leading to significantly lower background noise levels. Important spectral changes are observed before and during the lockdown, suggesting a shift from anthropic to animal sources in the acoustic environment.

scholarly journals A New Method to Correct Radiosonde Temperature Biases Using Radio Occultation Data

2017 ◽  
Vol 56 (6) ◽  
pp. 1643-1661 ◽  
Author(s):  
Jordis S. Tradowsky ◽  
Chris P. Burrows ◽  
Sean B. Healy ◽  
John R. Eyre
Keyword(s):  
Radio Occultation ◽  
Weather Prediction ◽  
A Priori ◽  
Elevation Angle ◽  
New Method ◽  
Retrieval Algorithm ◽  
Temperature Bias ◽  
Linear Version ◽  
The Difference ◽  
The Impact

AbstractA new method to estimate radiosonde temperature biases using radio occultation measurements as a reference has been developed. The bias is estimated as the difference between mean radio occultation and mean radiosonde departures from collocated profiles extracted from the Met Office global numerical weather prediction (NWP) system. Using NWP background profiles reduces the impact of spatial and temporal collocation errors. The use of NWP output also permits determination of the lowest level at which the atmosphere is sufficiently dry to analyze radio occultation dry temperature retrievals. The authors demonstrate the advantages of using a new tangent linear version of the dry temperature retrieval algorithm to propagate bending angle departures to dry temperature departures. This reduces the influence of a priori assumptions compared to a nonlinear retrieval. Radiosonde temperature biases, which depend on altitude and the solar elevation angle, are presented for five carefully chosen upper-air sites and show strong intersite differences, with biases exceeding 2 K at one of the sites. If implemented in NWP models to correct radiosonde temperature biases prior to assimilation, this method could aid the need for consistent anchor measurements in the assimilation system. The method presented here is therefore relevant to NWP centers, and the results will be of interest to the radiosonde community by providing site-specific temperature bias profiles. The new tangent linear version of the linear Abel transform and the hydrostatic integration are described in the interests of the radio occultation community.

New Mathematical Model of Solar Flux Radiation for Double-Pitched Roof Surface

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Mohamed Harimi ◽  
Kiam Beng Yeo ◽  
Nordin Othman
Keyword(s):  
Mathematical Model ◽  
Natural Ventilation ◽  
Cooling System ◽  
Point Of View ◽  
Solar Flux ◽  
Passive Cooling ◽  
Proposed Model ◽  
The Difference ◽  
The Impact ◽  
Passive Cooling System

The aim of this research is to simplify an existing model (model-1) of solar flux radiation containing many parameters as compared to a new mathematical model (model-2) using just two independent variables, time and roof's angle of inclination. The impact of the solar radiation on the surface of the roof in Sabah (state of Malaysia) has been examined under different orientations and slopes by means of model-1 at different time of the day. Furthermore, the data of solar flux radiation computed using model-1 has been explored to develop the model-2 from which the correlation coefficient of 0.87 was achieved using regression analysis. It has been proven statistically using the t-test that the difference between the existing model-1 and the proposed model-2 is not significant. The new mathematical model-2 developed can be applied for a double-pitched roof at any given orientation in the area of Sabah only, where the slope of the roof and the local time have to be taken from 0 to 75 degrees and from 7 hrs to 17 hrs, respectively. Additionally, the method used in the derivation of this new model can also be employed for other states of Malaysia as well as other countries. From a technical point of view, the architects or designers can use the proposed model for a quick estimation of solar flux radiation, to identify the type of insulations to be applied under the roof or above the ceiling, as well as the size area of the natural ventilation and the decision-making on the thermal system to be employed, either as an active or a passive cooling system.

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