scholarly journals Evaluating the Tire/Pavement Noise and Surface Texture of Low-Noise Micro-Surface Using 3D Digital Image Technology

2021 ◽  
Vol 8 ◽  
Author(s):  
Wang Chen ◽  
Mulian Zheng ◽  
Haiyang Wang
Keyword(s):  
Noise Reduction ◽  
Digital Image ◽  
Surface Texture ◽  
Three Dimensional ◽  
Low Noise ◽  
Road Noise ◽  
Texture Model ◽  
Promising Tool ◽  
Absorbing Materials ◽  
Reduction Effect

As a common preventive maintenance technique for asphalt pavement, micro-surface (MS) has the advantages of waterproofing and crack sealing. However, issues such as the fact that the conventional MS generates large noise and the evaluation of the indexes of tire-road noise are relatively less studied. The traditional surface texture index cannot reveal the range and distribution of pavement surface texture, thus hindering research of low-noise MS. To study the mechanism of tire-road noise generated by MS, and propose the tire-road noise and surface texture indicators for MS. In this study, the mechanism of five low-noise MS was systematically analyzed and compared through surface texture and noise tests. Then, a three-dimensional digital texture model (3D-DTM) of MS surface texture was constructed using a series of digital image processing techniques, including grayscale identification, binary conversion, and noise reduction. The results show that optimizing the gradation, adding sound-absorbing materials, and improving the workability of construction can improve the noise reduction performance of MS, it is worth mentioning that the MS prepared with sound-absorbing materials and low-noise gradation has the greatest noise reduction effect, with a maximum reduction of 6.3 dB(A). In addition, it was also found that the 3D-DTM can well reflect the surface texture characteristics of MS. The probability of convex peak distribution (PCD) and the proportion of convex peak area (PCA) with peak heights greater than 0.25 mm (Kh ≥ 0.25), which are extracted from the 3D-DTM, can well reflect the surface texture, tire-road noise, respectively. The results show that the 3D-DTM is a promising tool to optimize the design of low-noise MS.

scholarly journals Reduction of Hydrodynamic Noise of 3D Hydrofoil with Spanwise Microgrooved Surfaces Inspired by Sharkskin

2019 ◽  
Vol 7 (5) ◽  
pp. 136 ◽  
Author(s):  
Zhigao Dang ◽  
Zhaoyong Mao ◽  
Wenlong Tian
Keyword(s):  
Noise Reduction ◽  
Three Dimensional ◽  
Low Noise ◽  
Numerical Predictions ◽  
Large Eddy ◽  
Flow Induced Noise ◽  
Hydrodynamic Noise ◽  
Reduction Effect ◽  
Underwater Structures ◽  
Good Agreement

Loud hydrodynamic noise is not only potentially harmful to the health of organisms in the ocean, but it is also a threat to the survival of underwater vehicles. Different from the general noise reduction technologies at present, a new idea for a flow-induced noise reduction design with spanwise microgrooved surfaces inspired by sharkskin is introduced in this paper. Large eddy simulations (LES) combined with the Ffowcs Williams and Hawkings (FW-H) equation are adopted to simulate the hydrodynamic noise of the three-dimensional (3D) hydrofoil. The accuracy of the numerical predictions is checked against existing experimental data, achieving good agreement. With the increase of observing distance, the noise reduction effect at the trailing edge direction is gradually apparent, and a maximum noise reduction of up to 7.28 dB can be observed. It is seen from the noise spectra of the biomimetic hydrofoil that the main peaks are eliminated, and the noise level at high frequency is also decreased. The cause of noise reduction lies in the secondary vortex generated in the microgrooves, which hinder the process of turbulence, consume the energy of the flow, and weaken the intensity of turbulent burst. The results of this study provide a new way to design low-noise underwater structures with hydrofoils.

Comparison of Noise Reduction Performance Evaluation Methods for Low-Noise Pavement in Korea- Part

2021 ◽  
Vol 263 (4) ◽  
pp. 2930-2939
Author(s):  
Byungchae Kim ◽  
Hyunjin Kim ◽  
Wonuk Kang
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Measurement Method ◽  
Road Traffic ◽  
Low Noise ◽  
Management Standards ◽  
Close Proximity ◽  
Porous Pavement ◽  
Reduction Effect ◽  
Measurement Location

In Korea, road noise is assessed as a measurement method of exterior noise emitted by road vehicle for management standards by the National Institute of Environmental Sciences. In this method, the noise felt at the actual pickup point is measured as LAeq (the roadside equivalent noise level). Recently, to clarify the standard for measuring noise on low-noise pavements, the CPX (ISO11819-2; Close-proximity method) was first introduced in the Porous Pavement Guidelines of the Ministry of Land, Infrastructure and Transport. According to ISO, the CPX adopts the side microphone as a mandatory measurement location, and the rear optional. The side location has been a mandatory due to its high correlation with SPB (ISO 11819-1, Statistical Pass-by method). However, according to our previous study on the correlation evaluation between L and CPX rear microphone noise level, both noise reduction effect was about 9-12 dB(A) showed a high correlation in Korea where heavy road traffic is common. The following study aims to show the consistent correlation between the L and CPX rear noise level. Furthermore, it is intended to be helpful in selecting the location of the CPX microphone that can most effectively represent the actual noise on the low-noise pavement in Korea.

Optimized Asphalt Mixtures for Noise Reduction in Lithuanian Roads

2014 ◽  
Vol 614 ◽  
pp. 618-621
Author(s):  
Audrius Vaitkus ◽  
Tadas Andriejauskas ◽  
Laura Čygaitė ◽  
Jurgita Židanavičiūtė
Keyword(s):  
Noise Reduction ◽  
Noise Pollution ◽  
Low Noise ◽  
Asphalt Pavements ◽  
Noise Levels ◽  
Road Noise ◽  
Negative Effects ◽  
Development Experience ◽  
Growing Economy ◽  
Generation Mechanisms

In the world of growing economy and population, the need of transportation is rapidly increasing also raising problems of noise pollution. Environmental noise levels are increasing in parallel with increasing traffic flows resulting negative effects for society, wildlife and economy. The article gives an overview about the main transport noise source tyre/road noise, its generation mechanisms and influencing factors. One of the most effective and promising tyre/road noise solutions is low noise pavements, which has different noise reduction approaches. Low noise asphalt pavements and theoretical noise reduction principles are analysed in the paper as well as the development experience of particular low noise asphalt pavements for Lithuanian conditions.

Noise Reduction Technique for Digital Image Based Full Field Strain Measurement

2012 ◽  
Author(s):  
Yoshitaka Wada ◽  
Tomonari Furukawa
Keyword(s):  
Noise Reduction ◽  
Digital Image ◽  
Strain Measurement ◽  
Low Noise ◽  
Reduction Technique ◽  
Distortion Correction ◽  
Image Correlation ◽  
Full Field ◽  
Deformation Problem ◽  
Noise Reduction Technique

In recent years several techniques of full-field measurement have been studied by digital image correlation method, moiré interference method and holographic interferometry method and so on. Image based method can be easily applied to large deformation problem and moving specimen at slow speed. Because digital camera capabilities, which are high resolution, low noise and faster data transfer speed, have been improved, very small strain measurement can be achieved by those improvements. The improvement will widen those applications, for example, moving object at high speed and less 0.1% strain measurement which is almost the same accuracy with a precise strain gauge. In order to apply the advanced application, noise reduction for a digital image and lens distortion correction for an optical system should be developed. In this paper we propose noise reduction technique using statistical camera model to be applied to any kinds of digital cameras.

scholarly journals Layout Method of Damping Material for Gearbox Based on Acoustic Contribution

2019 ◽  
Vol 37 (4) ◽  
pp. 757-766
Author(s):  
Yunong Liu ◽  
Lan Liu ◽  
Geng Liu ◽  
Liyan Wu ◽  
Chao Liu ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Present Method ◽  
Element Model ◽  
Low Noise ◽  
Radiated Noise ◽  
Damping Material ◽  
Plate Area ◽  
Acoustic Contribution ◽  
Reduction Effect ◽  
Damping Materials

In order to realize the low noise design of marine gearbox, a layout method of damping materials for gearbox based on acoustic contribution was proposed. The present method can accurately and effectively determine the additional area of damping materials and achieve greatly the noise reduction effect. Firstly, taking a marine single-stage herringbone gearbox as the object, the finite element/boundary element model for the reducer structure was established. After applying the vibration excitation of the gear system, the radiated noise of each field point was solved. Secondly, by analyzing the acoustic transfer vector (ATV) and modal acoustic contribution (MAC), the surface of the gearbox was partitioned, and the partitioned surface was analyzed by using panel acoustic contribution (PAC). Finally, the damping material was added to the plate area which contributes greatly to the radiated noise, and the effect of the noise reduction under different schemes were compared. The results show that the layout design of damping materials based on the present method can reduce the radiation noise of observation points accurately and effectively in the range of 0~4 000 Hz.

Low Noise FEGV Designed by Numerical Method Based on CFD

2004 ◽  
Author(s):  
Naoki Tsuchiya ◽  
Yoshiya Nakamura ◽  
Shinya Goto ◽  
Hidekazu Kodama ◽  
Osamu Nozaki ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Guide Vane ◽  
Three Dimensional ◽  
Leading Edge ◽  
High Amplitude ◽  
Aerodynamic Performance ◽  
Low Noise ◽  
Test Facility ◽  
Noise Sources ◽  
Fan Noise

This paper describes a low noise FEGV (Fan Exit Guide Vane), which is designed by a fan noise prediction method based on CFD. Fan noise is predicted by a hybrid scheme, which is the combination of three-dimensional CFD and three-dimensional linear theory. Characteristics of noise sources are investigated in some kinds of FEGV shapes. High amplitude areas spread not only along the leading edge but also in the span-wise positions along the mid-chord. It is found that high amplitude areas around the mid-chord make an important role in noise generation, and appropriate aft-ward swept angle and span-wise distribution of leaned angle could reduce the amplitude of the noise sources keeping aerodynamic performance. A fan noise test for fan scale models has been conducted at an anechoic test facility in IHI Mizuho to demonstrate noise reduction and performance of low noise FEGV. Noise reduction can be achieved keeping aerodynamic performance compared to conventional straight FEGV.

scholarly journals Initial Field Validation of Poroelastic Pavement Made with Crumb Rubber, Mineral Aggregate and Highly Polymer-Modified Bitumen

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1339
Author(s):  
Piotr Jaskula ◽  
Jerzy Ejsmont ◽  
Marcin Stienss ◽  
Grzegorz Ronowski ◽  
Cezary Szydlowski ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Traffic Noise ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Low Noise ◽  
Base Layer ◽  
Road Noise ◽  
Modified Bitumen ◽  
Initial Field ◽  
Mineral Aggregate

Tire/road noise in most driving conditions dominates other sources of traffic noise. One of the most efficient ways of reducing tire/road noise is to use the so-called “low noise pavement”. According to numerous studies, at present, poroelastic road pavement that is composed of rubber and mineral aggregate and polyurethane or bituminous binder gives the best noise reduction up to 12 dB. Unfortunately, there are many problems with making durable poroelastic pavements. This article presents the first results of a project that is executed in Poland and aims at the development of a durable, low noise poroelastic pavement based on polymer-modified asphalt binder called Safe, Eco-friendly POroelastic Road Surface (SEPOR). Two test sections were built in 2019 to test the production technology and performance of the SEPOR pavement. It is observed that some of the problems with previous poroelastic materials were mainly eliminated (especially delamination from the base layer and raveling) but noise reduction is a little less than expected (up to 9 dB). Rolling resistance for car tires is acceptable and fire properties (damping of spill fuel fires, toxic gas emission) are very good.

An Enhanced End Milling Surface Texture Model Including the Effects of Radial Rake and Primary Relief Angles

1994 ◽  
Vol 116 (2) ◽  
pp. 166-174 ◽  
Author(s):  
S. N. Melkote ◽  
A. R. Thangaraj
Keyword(s):  
Surface Roughness ◽  
Surface Texture ◽  
End Milling ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Surface Profile ◽  
Dimensional Structure ◽  
Machined Surface ◽  
Texture Model ◽  
Parameter Values

An enhanced surface texture model for predicting the two- and three-dimensional structure of the surface generated by the end cutting edges on the bottom of an end mill is presented. This model includes the effects of the radial rake and the primary end tooth relief angles which have been neglected in the models available to date. Non-ideal effects such as cutter runout and back-cutting are explicitly modeled. An algorithm to simulate the two- and three-dimensional milled surface is presented. It is shown that the main effect of the radial rake and the primary end tooth relief angles is to increase the surface roughness parameter values. The effectiveness of the enhanced model in accurately capturing the major features of the machined surface texture and in closely predicting the roughness parameter values is demonstrated through experiments and model simulations. It is shown that the enhanced model predicts both the shape of the surface profile and the surface roughness parameters more accurately than the existing models in the literature.

scholarly journals Asphalt Pavement Acoustic Performance Model

2019 ◽  
Vol 11 (10) ◽  
pp. 2938 ◽  
Author(s):  
Rita Kleizienė ◽  
Ovidijus Šernas ◽  
Audrius Vaitkus ◽  
Rūta Simanavičienė
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Asphalt Mixture ◽  
Low Noise ◽  
Asphalt Mixtures ◽  
Mixture Composition ◽  
Void Content ◽  
Road Noise ◽  
Air Void ◽  
Air Void Content

Low-noise pavements are used as an effective method of traffic noise mitigation. Low-noise pavements reduce the noise that arises due to interactions between tires and road surfaces (tire/road) via the implementation of three main components: low pavement roughness, negative pavement texture, and a high pavement air-void content. The tire/road noise reduction capabilities of the wearing layer vary depending on the aggregate type, gradation, bitumen and air-void content, and density. Consequently, the demand for an accurate tire/road noise prediction model has arisen from the design of asphalt mixtures. This paper deals with how asphalt mixture components of the wearing layer influence tire/pavement noise reduction and presents a model for tire/road noise level prediction based on the asphalt mixture composition. The paper demonstrates that the noise reduction level of low-noise asphalt pavements is dependent on the composition of the asphalt mixture. Asphalt wearing layer mixture composition parameters were tested in the laboratory from cores taken from 18 road sections, where acoustic properties were measured using a close-proximity (CPX) method. The proposed linear model is based on the bitumen amount, the air-void content of the mixture and aggregate shape and involves materials that comply with the general requirements for high-quality asphalt mixtures. The model allows for the prediction of the tire/road noise level at the asphalt mixture design stage using asphalt mixture components and volumetric properties. The proposed model is the first stage in the building of a complex model with a much wider range of low-noise asphalts components, pavement profile depth and CPX-value relationships.

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