Noise Prediction Software Research Articles

Analysis of road traffic noise in an urban area in Croatia using different noise prediction models

Abstract Road traffic noise is the second largest environmental stressor in urban areas in Europe after air pollution. The harmful effects of noise arise mainly from the stress response it triggers in the human body, which can have significant consequences for physical and mental health. Therefore, the use of a reliable noise prediction model is an important prerequisite for the quality assessment of a number of residents exposed to excessive noise levels and for the selection of appropriate noise mitigation measures. In this study, the analysis of road traffic noise in an urban street in the narrower centre of the Croatian capital Zagreb was performed using four noise prediction models: "RLS-90", "RLS-19", “NMPB-Routes-96 (SET-RA-CERTU-LCPC-CSTB)”, and “CNOSSOS-EU”. LimA V2021 noise prediction software was used for the analysis, and the noise modelling results were validated with short-term noise measurements. The main objective of the research presented in the article was to test the “CNOSSOS-EU” method, recently introduced in Croatian noise control practice, and to gain initial insights into which of the aforementioned noise prediction models is the most reliable for the assessment of road traffic noise in urban environments in Croatia. A comparison of the noise modelling results with the results of short-term noise measurements has shown that the German national calculation methods “RLS-90” and “RLS-19” as well as the “CNOSSOS-EU” method provide significantly more accurate noise predictions than the “NMPB-Routes-96 (SETRA-CERTU-LCPC-CSTB)” method.

Prediction and Analysis of Noise Impact and Noise Reduction Scheme Effect for Complex Road Types

In order to improve urban traffic efficiency, complex road types are increasingly common in cities. At the same time, it also increases the impact of noise. As an important noise reduction measure, noise barrier measures are widely used in traffic noise control. The prediction of noise reduction scheme in advance is conducive to the scientific and reasonable setting of noise barrier measures. In this paper, based on the impact of traffic noise from elevated roads on a residential building, the noise prediction software is used to simulate the scene, and the model is calibrated with the field measured data, and the noise contribution of elevated road and ground road to sensitive targets is quantitatively analyzed. On this basis, the noise reduction effects of different types of noise barrier measures, such as vertical, bending, semi-closed and fully-closed, on sensitive targets are analyzed. The effect of different additional length on noise reduction is further analyzed. The simulation analysis also focuses on the key buildings and floors that are seriously affected by road noise, providing sufficient technical support for the implementation of the subsequent overall noise reduction project.

Validation of environmental noise models from a manufacturer's persepctive

Validation is a critical part of the modelling process. Without this stage, it may be impossible for users to tell how close their model is to the real world. Validating an environmental noise model can be tricky, but there are some important ideas to keep in mind that can help you. DataKustik, the developers of the environmental noise prediction software CadnaA, and Scantek, Inc., the sole distributor of DataKustik products in North America, would like to offer some dos and don’ts of validating an environmental noise model from a manufacturer’s point of view.

Using GIS techniques for modeling of anthropogenic noise propagation generated by a chainsaw in forest harvesting

Noise is an environmental pollution that negatively affects human health and reduces the performance of employees. Forest harvesting activities are one of the working environments where noise effect is intense. The most common equipment used in forest operations is chainsaw whose noise affects not only the operator but also the wildlife in the territory. The noise maps showing noise propagation can be effectively used in evaluating and controlling the noise effects. In this study, it was aimed to measure the anthropogenic noise levels ​​resulting from the chainsaw used in tree felling and to map its noise propagation with SPreAD-GIS (System for Prediction of Acoustic Detectability) which is a GIS (Geographical Information Systems) based noise prediction software. The study was conducted in Karacabey Flooded Forest within the city of Bursa in Türkiye. The results indicated that the average noise level from the chainsaw was above the danger limit (90 dBA) that causes increased physiological reactions and headache on the workers. According to the noise propagation map, the noise exposure of the employees exceeded the warning limit (85 dBA) and the maximum noise level was 95.96 dBA during the harvesting activity. In some parts of the study area, the noise level was 45 dBA or above, causing negative effects on bird species. It can be concluded that the noise maps can be effectively used to determine noise propagation generated by a chainsaw and evaluate the noise effects on the operators and as well as on the bird species in the perimeter.

Finite Element Method for the Estimation of Insertion Loss of Noise Barriers: Comparison with Various Formulae (2D)

Noise barriers are a critical part of noise mitigation in urban and rural areas. In this study, a comparison of the insertion loss calculations of noise barriers via the Finite Element Method (FEM) and various formulae (Kurze–Anderson, ISO 9613-2/Tatge, Menounou) is presented in the case of two-dimensional acoustic radiation problems. Some of the cases explored include: receiver in the illuminated zone, in the shadow zone, in the shadow border, source in medium, long, short distance from the barrier, source and receiver near barrier, and source above the barrier. Comparisons of the results indicate that FEM results comply well (less than 1 dB in each case) with Menounou’s formula which in turn complies with the analytic solution (MacDonald Solution). In certain cases, the differences between FEM and Menounou’s formula compared to Kurze–Anderson and ISO 9613-2/Tatge formulae are substantial (source and receiver near the barrier (10 dB) and source near the barrier and receiver in the shadow border (5 dB)). Similar differences are also confirmed by the analytic solution. The findings suggest that FEM can be applied effectively for the precise estimation of the insertion loss of noise barriers. Especially in cases where ISO 9613-2 formula shows large deviations from the analytic solution (e.g., near barrier), possible applications may arise in cases such as balconies, facades, etc. Furthermore, the study supports the idea that FEM could possibly be effectively utilized in real life applications for microscale urban acoustic modeling as a viable alternative to expensive noise prediction software.

Noise predictions of sound systems using system data and complex summation

As the number and size of amplified outdoor events in urban areas is increasing, so are the challenges with accompanied noise immissions and therefore the need for accurate noise predictions. An advanced method for predictions of sound systems is introduced, that uses specific system data and applies complex summation. The system data, including all acoustically relevant characteristics, such as positioning, orientation and directivity of loudspeakers, delays and electronic filters, are simply imported with a system design file already in use by the system provider (d&b’s ArrayCalc simulation software). This procedure eliminates any inaccuracies and inefficiencies because it spares the process of re-modeling a sound system in the noise prediction software and ensures predictions using the actual system design. Also, and with increasing importance, advanced electronic filtering (e.g., IIR, FIR) is automatically included. Environmental noise modelling software usually does not consider complex summation between sources because they are assumed to be un-correlated with one another (as in traffic and industry). However, in sound systems, the signals sent to the loudspeakers are mostly correlated. Furthermore, modern line-array systems use coherence effects to further tailor directivity. Therefore, the sound propagation calculation was extended for complex summation and the method was implemented in SoundPLAN software and in NoizCalc (d&b audiotechnik).

Management at corporate level of noise exposure assessment and control for Petrobras refining

This article presents the work carried out as part of a project aiming to regulate the noise exposure of workers of PETROBRAS refining units. This is a corporate project carried out over a three years’ period (2012 to 2015) by the Supply business unit of the Brazilian company. The uniqueness of this project is due to its scale. Indeed, this encompassed twelve refineries located throughout Brazil. The corporate approach to deal with noise exposure risk leads to an overall data consolidation allowed by a standardized methodology. The methodology used is split into four phases. First, a long but necessary planning stage, then an exhaustive assessment of the current noise situation of production areas was carried out during the first twelve months of the project. This stage allowed the involvement of several important tools used to identify and rank noise exposure issues. This lead to noise maps of every industrial area and an acoustic database of equipment exceeding regulatory limits (sound power level and directivity). Third, every industrial area was modelled into noise prediction software compliant with ISO 9613-2 standard. Finally, acoustic damping solutions were designed and proportioned by size of equipment. This mixed approach of measurement and numerical simulation mobilized a dedicated ACOEM project team comprising of eight acoustic experts. Principal achievement of this project, concluded in 2015, is a clear vision of the noise control priorities allowed by standardized methodology on all refineries in a short time. This achievement leads to a coherent set of controls for the future investments to be done to mitigate noise exposure risks. In addition to highlighting the benefits of integrated Health Safety and Environment (HSE) management, this work provides an understanding on the use of virtual computing doses from propagating acoustic model.

Realizing modeling and mapping tools to study the upsurge of noise pollution as a result of open-cast mining and transportation activities.

Introduction:In open-cast mines, noise pollution has become a serious concern due to the extreme use of heavy earth moving machinery (HEMM).Materials and Methods:This study is focused to measure and assess the effects of the existing noise levels of major operational mines in the Keonjhar, Sundergadh, and Mayurbhanj districts of Odisha, India. The transportation noise levels were also considered in this study, which was predicted using the modified Federal Highway Administration (FHWA) model.Result and Discussion:It was observed that noise induced by HEMM such as rock breakers, jackhammers, dumpers, and excavators, blasting noise in the mining terrain, as well as associated transportation noise became a major source of annoyance to the habitants living in proximity to the mines. The noise produced by mechanized mining operations was observed between 74.3 and 115.2 dB(A), and its impact on residential areas was observed between 49.4 and 58.9 dB(A). In addition, the noise contour maps of sound level dispersion were demonstrated with the utilization of advanced noise prediction software tools for better understanding.Conclusion:Finally, the predicted values at residential zone and traffic noise are correlated with observed values, and the coefficient of determination, R2, was calculated to be 0.6891 and 0.5967, respectively.

Influence of the search radius in a noise prediction software on population exposure and human health impact assessments

Engineering software products allow for quantifying environmental noise and a population's exposure to road traffic noise which can then be linked to human health damage. This paper investigates the impact of the search radius, a parameter used in emission and propagation models, on noise exposure results. The search radius is the threshold distance from which noise sources are not considered anymore in the exposure assessment. To understand the influence of this parameter on the evaluation of population’s exposure, the search radius has been successively fixed to three different values (500m, 1000m and 2000m) in four different geographical situations (village, industrial, suburban and inner city). The result of this investigation highlights several points. First, despite a search radius often fixed to 1000m by noise prediction software users, going up to 2000m shows significant increase in population’s exposure. Second, the impact of a change in search radius is very dependent of the presence of preponderant noise sources. Third, increasing the search radius can quickly lead to an impractical calculation time. A solution to avoid underestimating the exposure without increasing too much the calculation time may be to only account for preponderant noise sources beyond a given distance.

The Research on Application of Cadna/A Software in Noise Prediction of Urban Substation

Nowadays, the environmental protection problem which is caused by urban substation noise is getting more and more serious. Before substation noise management, we should understand substation noise value at boundary or sensitive point and be able to reasonably judge noise para-normal area, distribution form, etc. In this paper, the Cadna/A calculation software is adopted to establish the substation prediction model. Through analyzing the characteristics of the urban substation, we compare actual test value and predictive value and verify the accuracy of the prediction. According to the real situation of substation, the parameter settings of noise prediction software were analyzed, and the basic principles of layout optimization based on noise control in substation were determined. After the layout optimization design of substations, the adjustment measures of main transformer, reactor, firewall and buildings were proposed. In this study, the parameter setting method in analysis of noise prediction was proposed. And it also provides technical basis for substation noise prediction. The layout optimization design method based on noise control was proposed.

Using mechanical noise prediction software to provide suitable solutions

Mechanical noise prediction softwares have become a useful tool for consultants to provide noise control recommendations. Two recent projects involving duct breakout will be analyzed to discuss how mechanical noise prediction softwares were used to analyze multiple solutions in order to provide a suitable solution for a medical office building and an open office space.

Development of a noise prediction software NASEFA and its application in medium-to-high frequency ranges

For the analysis of noise problems in medium-to-high frequency ranges, the energy flow boundary element method (EFBEM) has been studied. EFBEM is numerical analysis method of energy flow analysis (EFA), and solves energy governing equations using a boundary element method in complex structures. Based on EFBEM, a noise prediction software, “noise analysis system by energy flow analysis” (NASEFA), was developed. For effective maintenance, NASEFA is composed of three main modules: the translator, the model converter, and the main solver. The translator changes the FE model to the NASEFA BE model, and the model converter changes the BE model to an EFBE model, including various data, such as structural materials, medium properties, sources, and boundary conditions. NASEFA then solves the acoustic energy density and intensity on boundary and in the field. Moreover, it analyzes interior and exterior noise problems for single and multiple domains in two and three dimensions. Finally, for the validation of the software developed, interior and exterior noise predictions of various structures were performed. The results obtained with NASEFA were compared with those of the commercial SEA program and experiment. From these comparative studies, the usefulness of NASEFA was established.

Sensitivity analysis of simulation model on railway rolling noise prediction

The railway rolling noise prediction software (RRNPS) is a simulation model for predicting the sound pressure levels during a train passage due to wheel/rail roughness, based on vibration dynamics, contact mechanics and sound radiation modules. Some field validation has been done under European and Australian conditions. Comparisons between simulations and measurements have shown that this software model gives reliable predictions in terms of overall A-weighted sound pressure level and noise spectrum. In this paper, based on a typical railway rolling noise situation in Australia (a series of field measurements were taken at a narrow track gauge testing site), a sensitivity analysis of the RRNPS was carried out to investigate the effect of train speed, normal load, sleeper spacing, rail pad stiffness, track gauge and rail cross receptance factor on railway rolling noise. The results provide some insight into model-based methods to control and mitigate railway noise at its source.

Validation of a prediction model for tangent rail roughness and noise growth

Railways can inevitably cause railway rolling noise, which is induced by both wheel and rail roughness. Due to the deformation and wear between the wheel/rail at the contact patch, the rail roughness may grow in amplitude after a number of wheelset passages. This results in increasing railway rolling noise. Rail roughness is a common aspect in all transit systems and much research has been pursued to predict and mitigate its growth on track but prediction of resultant noise growth has not been a focus. This paper provides the experimental validation of the modified Railway Rolling Noise Prediction Software (RRNPS) model for the prediction of rail roughness growth and corresponding noise growth. The model is a new framework to enable noise growth predictions due to rail roughness growth mechanics. It is validated by means of several experiments that have been performed along a straight railway line. Through comparisons between predictions and measurements, it is shown that the RRNPS model gives reliable predictions on rail roughness growth and corresponding noise growth. Subsequently this model is used to predict how speed, normal force, wheelset traffic and ballast vertical stiffness affect rail roughness growth and corresponding noise growth.

The Influence of Visibility Conditions in Horizontal Road Curves on the Efficiency of Noise Protection Barriers

Abstract Ensuring sufficient visibility on planned roads by sight distance testing is an integral part of every project, but problems with visibility can emerge when noise barriers are erected on existing roads. Namely, in order to provide sufficient noise protection, high noise barriers are often placed at minimum distance from the carriageway edge, and additional visibility testing in most cases is not carried out. Research described in this paper consists of stopping sight distance tests conducted by means of specialized road design software MX Road, and noise barrier optimization conducted by means of specialized noise prediction software LimA using static noise calculation method RLS 90. The aim of this research is to establish whether the required stopping sight distance on road sections where minimum design parameters are applied can be achieved if the noise barrier is placed at minimum distance from the carriageway edge, and to establish whether the optimized dimensions of planned noise protection barrier will change if the barrier is placed on larger distance from the noise source, which is, in this case, the existing road.

The Analysis of Low Noise Protection Barriers Influence on Tram Traffic Noise Levels

Abstract The paper describes the analysis of tram traffic noise situation in residential areas in the vicinity of Drzic Avenue, one of the major routes between the northern and southern part of the Croatian capital city Zagreb, and the effect of low barriers placed by the tracks on tram noise mitigation. In order to evaluate the effect of planned protection measure, noise models were produced and verified with short-term field measurements. Calculations were conducted by means of noise prediction software, using European interim noise prediction method and 3D model of analyzed area. Finally, the results of noise calculations for existing tram traffic situation and planned measure of protection are presented on noise maps.

Railway rolling noise prediction: field validation and sensitivity analysis

The Railway Rolling Noise Prediction Software (RRNPS) is a model for predicting the sound pressure levels (SPLs) during a train passage due to wheel/rail roughness, based on vibration dynamics, contact mechanics and sound radiation modules. Similar software has been developed previously, in particular the Track–Wheel Interaction Noise Software (TWINS) model, and some field validation has been done under European and Japanese conditions. In this article, the RRPNS is used to model a typical railway rolling noise situation in Australia and compared with detailed field experimental results for validation purposes. A series of field measurements were taken at a narrow track gauge testing site in Australia. Comparisons between simulations and measurements have shown that this software model gives reliable predictions in terms of overall A-weighted SPL and noise spectrum. In addition, a sensitivity analysis of the model was carried out to investigate the effect of speed, normal load, ballast vertical stiffness, rail pad vertical stiffness and rail cross receptance factor on railway rolling noise. This article extends the range of conditions for which the software model has been validated and gains some confidence in its use. It also provides some insight into model-based methods to control and mitigate railway noise.

중고주파수 대역의 회전형 압축기 진동소음 해석

Power flow analysis(PFA) is introduced for solving the noise and vibration analysis of system structures in medium-to-high frequency ranges. The vibration analysis software, <TEX>$PFADS_{C++}$</TEX> R4 based on power flow finite element method(PFFEM) and the noise prediction software, <TEX>$NASPFA_{C++}$</TEX> R1 based on power flow boundary element method(PFBEM) are developed. In this paper, the coupled PFFE/PFBE method is used to investigate the vibration and radiated noise of the rotary compressor. PFFEM is employed to analyze the vibrational responses of the rotary compressor, and PFBEM is applied to analyze the radiation noise around rotary compressor. The vibrational energy of the structure is used as an acoustic intensity boundary condition of PFBEM. Numerical simulations are presented for the rotary compressor, and reliable results have been obtained.

파워흐름해석법을 이용한 중고주파수 대역 소음해석 프로그램 개발

2 Abstract Flow Analysis (PFA) is introduced for solving the noise and vibration analysis of structures in medium-to-high frequency ranges. The vibration analysis software, PFADSC++ R4 based on Power Flow Finite Element Method (PFFEM) and the noise prediction software, NASPFAC++ R1 based on Power Flow Boundary Element Method (PFBEM) are developed. In this paper, the coupling equation which represents relation between structural energy and acoustic energy is developed for vibro-acoustic coupling analysis. And vibro-acoustic coupling analysis software based on PFA and coupling equation is developed. Developed software is composed of translator, cavity-finder, solver and post-processor over all. Translator can translate FE model into PFADS FE model and cavity-finder can automatically make NASPFA BE model from PFADS FE model for noise analysis. The solver module calculates the structural energy density, intensity of structures, the fictitious source on the boundary and the acoustic energy density at the field in acoustic cavities. Some applications of vibro-acoustic coupling analysis software to various structures and cruise ship are shown with reliable results.

공력음향학을 이용한 축류홴의 삼차원 소음 해석

This paper presents a systematic procedure for three-dimensional noise analysis of an axial-flow fan by using computational aero-acoustics based on Ffowcs Williams-Hawkings equation. Flow-fields of a basic fan model are simulated by solving three-dimensional, unsteady, Reynolds-averaged Navier-Stokes equations using the commercial code ANSYS CFX 11.0. Starting with steady flow results, unsteady flow analysis is performed to extract the fluctuating pressures in the time domain at specified local points on the blade surface of the axial flow fan. The perturbed density wave by rotating blades reaches at the observer position, which is simulated by an in-house noise prediction software based on Ffowcs Williams-Hawkings equation. The detailed far-field noise signatures from the axial-flow fan are analyzed in terms of source types, field characteristics, and interpolation schemes.