| 1. |
- Bühlmann, Erik, et al.
(författare)
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An in-depth look at the tire rubber hardness influence on tire/road noise measurements
- 2018
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Ingår i: INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering. - : Institute of Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- When assessing the acoustic quality of a road pavement with the close-proximity (CPX) or the on-board sound intensity (OBSI) method, the rubber hardness of the reference tire substantially affects the measurement. Practical experience shows that measurement tires can get significantly harder within a single measurement season. This is why one would like to normalize measurements to a reference rubber hardness. The recently published technical specification defining the reference tires for CPX measurements (ISO/TS 11819-3), therefore, includes a new correction for tire rubber hardness. Early experiences with this new correction procedure raised questions about its accuracy. This paper takes an in-depth look on the influence of tire rubber hardness on CPX measurements for both reference tires P1 and H1. It analyses existing and new data and summarizes the research from several scientific contributions on this topic. It provides evidence that the effect of rubber hardness is tire specific and that separate correction factors for the P1 and the H1 tires lead to accuracy gains and improved repeatability and reproducibility of the method. The study concludes by proposing a revised tire-specific approach for the tire rubber hardness correction of CPX measurement results.
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| 2. |
- Bühlmann, Erik, et al.
(författare)
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Speed dependency of temperature effects on road traffic noise
- 2015
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Ingår i: INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- Recently, a new literature review on the influence of temperature on tire/road noise became available, based on a compilation of large amounts of data from empirical research. This review showed that the effect of temperature is roughly double of that previously assumed and taken account of in international standards. This makes temperature one of the main sources of error in measurement results. Furthermore, it suggested that an additional refinement of the correction approach may be required to improve the accuracy of measurements. As a first attempt for this refinement, this article focuses on the speed dependency of temperature effects.Some past work has detected an influence of speed on the temperature effect, but did not succeed in quantifying this influence or in describing the exact pattern of speed dependency. This work aims to fill this gap byinvestigating speed dependency of temperature effects on tire/road noiseestimating the temperature influence on noise generation mechanisms together with their change with speed, andevaluating the speed influence on overall road traffic noise by including a propulsion noise component while using a new European traffic noise emission model.The article concludes by proposing a method to deal with speed dependency of temperature effects on both, CPX (or OBSI) and SPB measurements, with the ultimate goal of increasing the accuracy of measurement results.
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| 3. |
- Conter, Marco, et al.
(författare)
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ROSANNE project : New procedure for noise characterization of road surfaces in Europe
- 2016
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Ingår i: Proceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering. ; , s. 4997-5005
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Konferensbidrag (refereegranskat)abstract
- ROSANNE is a collaborative project in the 7th EU Framework Program which aims at harmonizing measurement methods for skid resistance, noise emission and rolling resistance of road pavements as a preparation for standardization. The project started in November 2013 and is developing and improving standards in the field of working group CEN/TC 227/WG 5.Regarding the influence of the pavement on the road traffic noise emission, the main objective is to combine the existing measurement methods of SPB (ISO 11819-1) and CPX (ISO/DIS 11819-2) into a stable and reliable harmonized pavement noise emission characterization method. A respective procedure is being developed within the project and its potential use for noise calculation methods like the one proposed by the CNOSSOS-EU project is investigated. The first two years of research focused on analyzing and comparing existing noise measurement methods to specify the noise properties of road surfaces as well as investigating the temperature influence of possible correction measures; respective results will be presented in a separate paper on this issue within this conference. Activities related to the compatibility with the CNOSSOS-EU calculation method and to the experimental validation are still ongoing. The present paper shows the current draft of the procedure developed.
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| 4. |
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| 5. |
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| 6. |
- Ejsmont, Jerzy, et al.
(författare)
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Tyre/road noise reduction by a poroelastic road surface
- 2014
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Ingår i: INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering. - 9780909882037
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Konferensbidrag (refereegranskat)abstract
- Low noise road surfaces of existing types may in favourable cases and in new conditions provide up to 7 dB of noise reduction. For higher noise reductions, innovative solutions must be sought. Poroelastic road surfaces (PERS) may be such a solution, which currently is studied in the EU project PERSUADE. This paper presents results of trials with a PERS version prefabricated by one of the project partners. Tests were made in a laboratory at TUG, where different tyres were tested on drums covered with PERS, and later field tests were made on a local street in Sweden where VTI had constructed a 25 m long trial section. The field tests were made with a CPX trailer from TUG. Both laboratory and field results showed that tyre/road noise reductions of 9-11 dB were achieved compared to a dense asphalt concrete pavement with maximum aggregate size 11 mm. This is the best result so far in the project. At the same time, this PERS, despite being relatively soft, reduces rolling resistance of passenger car tyres to record-low values, which is important for reducing fuel consumption and CO2 emissions. It is concluded that this type of prefabricated poroelastic road surface offers a very efficient way of reducing tyre/road noise, provided current durability problems can be solved.
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| 7. |
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| 8. |
- Sandberg, Ulf, 1946-, et al.
(författare)
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Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
- 2018
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Ingår i: INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering. - : Institute of Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- In 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved pavement in Huskvarna finally exceeded lifetime and durability expectations by at least 100 %. The first two years, noise reduction fell from the initial 7-8 dB just marginally, compared to an average-age SMA 16 pavement. Now after its 7th year, the pavement had reached its acoustical end of life, with an average noise reduction loss of 0.5 dB per year. This is considered as a break-through for low noise pavements exposed to the winter climate in Sweden and road traffic with most light vehicles equipped with studded tires. This paper presents results of annual noise measurements using the CPX method over the entire lifetime on the DPAC compared to the reference set of SMA 16 pavements. This includes the effects of grinding, cleaning and rejuvenation trials on certain test sections.
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| 9. |
- Sandberg, Ulf, 1946-, et al.
(författare)
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Comparison Of Noise Emission Of HCT And Classic Vehicle Combinations For Timber Transportation In Sweden
- 2018
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Konferensbidrag (refereegranskat)abstract
- By means of a special simulation tool, the noise emission of a high-capacity heavy vehicle (11 axles) was compared to that of a classic heavy vehicle (a truck-dolly-semitrailer with 8 axles). The two cases are designated “Extended vehicle” versus “Classic vehicle” in this study, having total lengths of 34 and 25 m, respectively. The Classic vehicle represents the most common articulated heavy vehicle configuration for transport of timber and other goods in Sweden. Tyres were assumed to be typical of each axle and their noise emission values were taken from a recent study. Noise from the propulsion unit were assumed to just meet the present maximum legal levels. It was found that noise emission from the Extended vehicle is approx. 1.5 dB higher than for Classic vehicle, as max. A-weighted level per vehicle passage, but as the number of vehicles in traffic is lower for a certain transportation volume, the resulting road traffic noise exposure in terms of A-weighted equivalent level LAeq is similar. Consequently, noise emission is not a factor that gives either vehicle type a clear advantage over the other.
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| 10. |
- Sandberg, Ulf, et al.
(författare)
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Improving the CPX method by specifying reference tyres and including corrections for rubber hardness and temperature
- 2016
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Ingår i: Proceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering. ; , s. 4913-4923
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Konferensbidrag (refereegranskat)abstract
- Recently completed work in the EU project ROSANNE and in working group ISO/TC43/SC1/WG33 has allowed substantial improvements to measurements made by the Close-Proximity (CPX) method, intended for measurement of noise properties of road surfaces. The paper summarizes the experimental work and describes the conclusions and implementation in ISO/FDIS 11819-2 (the CPX method) and in the supporting ISO (draft) Technical Specifications 11819-3 about Reference Tyres and 13471-1 about Temperature Corrections.In the Reference Tyre specification, two reference tyres are defined, of which one is the 16'' SRTT specified in ASTM 2493-14 and the other is a commercial light truck tyre. Both tyres have been tested with respect to correlations with SPB (pass-by) measurements and found to represent car and truck tyres, respectively, in this particular application. To account for reasonable ageing and minor production differences, a correction for rubber hardness is specified, in order to normalize measurement results to tyres having reference hardness. The Temperature Correction specification includes temperature coefficients that are used for normalizing noise levels to an air reference temperature of 20 degrees C. The coefficients relate to driving speed by a simple equation which is different for three categories of road surfaces, which are specified in the document.
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