Measurement and Assessment on Environmental Noise Impact of Electric Vehicles in Accelerating Condition

Noise emission from the vehicles propelled by electric system (such as pure electric and hybrid electric vehicles, EVs) is usually lower than the conventional internal combustion engine vehicles. Some previous studies have been shown the difference in A-weighted sound power level of EVs from the conventional ones. The difference is not dramatically large, i.e. less than 4 dB when the cars running at constant speed of 20 km/h. In this paper, we present the additional measurement results of sound power level of EVs in accelerating condition. Because when the cars in accelerating condition, the difference of propulsion systems becomes more significant on noise emission. The results are shown as regression model of sound power level depending on the vehicle speed. Moreover, the environmental noise impact of growing population of EVs is assessed through a prediction of at a case of intersection.

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A simulation of traffic noise emissions at a roundabout based on a cellular automaton model

Acta Acustica ◽

10.1051/aacus/2021037 ◽

2021 ◽

Vol 5 ◽

pp. 42

Author(s):

Canyi Du ◽

Xinfa Qiu ◽

Feng Li ◽

Ming Cai

Keyword(s):

Cellular Automaton ◽

Road Traffic ◽

Power Level ◽

Traffic Noise ◽

Traffic Volume ◽

Sound Power ◽

Noise Emission ◽

Urban Road ◽

Speed Distribution ◽

Sound Power Level

The calculation and evaluation of traffic noise is an important task in urban road design. Roundabouts are a common form of urban road intersection. The complexity of traffic operations makes the calculation of traffic noise near a roundabout challenging. To explore traffic noise at roundabouts, a cellular automaton traffic flow model for a two-lane roundabout is established. Based on this model, a dynamic simulation method for traffic noise at roundabouts is proposed. The traffic operation and noise emissions at a roundabout are simulated. The vehicle speed distribution and traffic noise distribution at the roundabout are analysed, and the relationship between the traffic volume and sound power level of the cells is discussed. Finally, the proposed method is compared with existing traffic noise models, and the accuracy and efficiency of the proposed method are verified. The results of this paper show that the speed distribution and noise emission distribution at the roundabout are not uniform. When the traffic volume increases to saturation, the noise emission on the ring road will not keep increasing, and the sound power level of the cells on the inner ring is approximately 2 dBA higher than that of the outer ring. The methods and results in this paper may be valuable for road traffic design and noise control.

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Analysis of the Sound Power Level Emitted by Portable Electric Generators (Outdoor Powered Equipment) Depending on Location and Measuring Surface

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.430.266 ◽

2013 ◽

Vol 430 ◽

pp. 266-275 ◽

Cited By ~ 1

Author(s):

Elena Postelnicu ◽

Valentin Vladut ◽

Cristian Sorica ◽

Petru Cardei ◽

Ion Grigore

Keyword(s):

Noise Source ◽

Power Level ◽

Acoustic Power ◽

Sound Power ◽

Noise Emission ◽

Sound Power Level ◽

Measuring Surface ◽

Measurement Surface ◽

Electric Generators

Acoustic power is a measure which must be specified on the outdoor used equipments and its determination depends on several factors: the place where the equipment works (indoor or outdoor), the placement of the microphones for its determination (the distance less or greater from the noise source), the shape of the measurement surface (parallelepiped or hemispherical). This paper aims to analyze the values obtained in these situations and interpret the data to determine the influence that each factor has on the acoustic power compared with the values obtained (permissible) according to Directive regarding noise emission D 2000/14/EC.

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Ecological assessment of noise impact of dry transformer substations on the environment

E3S Web of Conferences ◽

10.1051/e3sconf/202126502011 ◽

2021 ◽

Vol 265 ◽

pp. 02011

Author(s):

Sarkis Barseghyan ◽

Arman Hayrapetyan ◽

Armen Kirakosyan

Keyword(s):

Cooling System ◽

Negative Impact ◽

Power Level ◽

Sound Power ◽

Living Space ◽

Sound Power Level ◽

Transformer Substation ◽

Noise Impact ◽

The Impact ◽

Made In

At present, special attention is paid to assessing the negative impact of power facilities on the environment, including the impact of noise generated by power equipment. Power transformers are one of the sources of noise for industrial areas and the surrounding area. The noise of transformers is caused both by the vibration of its active part and by the fans of the cooling system, which is amplified by resonance phenomena in its individual elements. The presented work provides an environmental assessment of the noise impact of transformer substations. The noise impact of a transformer substation is considered on the example of three dry transformers in the area immediately adjacent to the living space. A new corrected approach was developed and tested for calculating the sound power level for dry transformers with the MatLab software package. An assessment of the noise impact of the projected transformer substation to install three dry transformers was the voltage class of which is 400 kVA, and one has 1000 kVA for the territory immediately adjacent to the living area was made. In our researches, the regulated noise characteristic for transformers is the corrected sound power level, which is indicated in the technical characteristics of the transformer. Calculations on non-standard nominal rated powers were carried out.

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Sound Intensity Mapping on Single Cylinder Direct Injection Diesel Engine with The Application of Palm Oil Methyl Ester Biodiesel

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.18.2.2021.21.0677 ◽

2021 ◽

Vol 18 (2) ◽

pp. 8833-8844

Author(s):

Mohd Shahrir Mohd Sani ◽

J.M. Zikri ◽

A. Abdul Adam

Keyword(s):

Methyl Ester ◽

Palm Oil ◽

Engine Speed ◽

Power Level ◽

Sound Intensity ◽

Sound Power ◽

Noise Emission ◽

Emission Analysis ◽

Intensity Mapping ◽

Sound Power Level

The utilisation of biodiesel nowadays has become familiar with rapid production types of biodiesel in order to replace the dependency on the fossil fuel parallel to the implementation of green technology that emphasises the products to be more environmental-friendly. Nevertheless, the emerges of various kinds of biodiesel cannot be simply used, despite using the biodiesel does not need any major modification on the engine; it still needs a few analyses that must be done to determine whether it will give advantages or disadvantages. Therefore, this research was carried out to investigate the effect of using palm oil methyl ester (POME) biodiesel on the engine in terms of noise emission. The sound intensity mapping method was used to indicate the effectiveness of the biodiesel by identifying the noise radiation. Along with the mapping, the sound power level (SPL) is also being obtained to provide a clear comparison between the parameters. Generally, switching up the engine speed and load increased the sound power level. Based on the results obtained related to the SPL, the intensity mapping tends to show a higher colour-coded in the noise source image for the higher engine speed and load setup. It was found that the engine speed and load give a significant contribution to noise emission produced by the engine, and it can be inferred that this method can be utilised to accomplish the noise emission analysis.

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Turbine Noise Reduction: Axial Spacing and Embedded Design

Volume 2B: Turbomachinery ◽

10.1115/gt2015-43565 ◽

2015 ◽

Cited By ~ 1

Author(s):

C. Faustmann ◽

S. Zerobin ◽

S. Bauinger ◽

A. Marn ◽

F. Heitmeir ◽

...

Keyword(s):

Power Level ◽

Low Pressure ◽

Sound Power ◽

Noise Generation ◽

Turbine Stage ◽

Noise Emission ◽

Low Pressure Turbine ◽

Sound Power Level ◽

Embedded Design ◽

Lp Turbine

This paper deals with the investigation on the acoustics of different turning mid turbine frames (TMTF) in the two-stage two-spool test turbine located at the Institute for Thermal Turbomachinery and Machine Dynamics (ITTM) of Graz University of Technology. The facility is a continuously operating cold-flow open-circuit plant which is driven by pressurized air. The flow path consists of a transonic turbine stage (HP) followed by a low pressure turbine stage made of a turning mid turbine frame (TMTF) and a counter-rotating low pressure rotor. Downstream of the low pressure turbine a measurement section is instrumented with acoustic sensors. Three TMTF setups have been investigated at engine like flow conditions. The first configuration (C1) consists of 16 highly 3D-shaped turning struts. The goal of the second design (C2) was to reduce the length of the TMTF by 10% without increasing the losses and providing comparable inflow to the LP turbine rotor. This was achieved by applying 3D-contoured endwalls at the hub. The third one (C3) is a new embedded concept for the turning mid turbine frame with two zero-lift splitters placed into the strut passages. In total 48 vanes (16 struts plus 32 splitter vanes) guide the flow from the HP rotor to the LP rotor. The comparison in terms of noise generation and propagation of the turbines is done by the microphones signal spectra, the emitted sound pressure and sound power level of each TMTF setup. Therefore the acoustic field is characterized by azimuthal and radial modes by means of a microphone array at the outer casing traversed over 360 degrees. By comparing the first two setups (C1 and C2) in terms of noise generation the propagating modes due to the HP turbine were found to be the same, while a difference of 5 dB in amplitude of the modes related to the LP turbine was found due to the different axial spacing between both setups. In the multi-splitter configuration (C3), the overall sound power level depending on the blade passing frequency (BPF) of the HP turbine is reduced by 7 dB and depending on the BPF of the LP turbine by 4 dB compared to C1, respectively. The overall effect is a reduction of the noise emission for the HP turbine due to the embedded design as well as for the LP turbine due to increasing the axial spacing between the TMTF Vanes and LP Blades on the one hand and considerably due to the embedded design on the other hand.

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