Road Noise Research Articles

Numerical investigation of the flow noise of an underwater vehicle

Flow noise is an important issue of underwater vehicles. In this paper, the ability of different numerical methods to predict the flow noise of the DARPA SUBOFF underwater vehicle model is investigated and compared. It is found that the front of the command deck and the tail fins are the main noise sources. Numerical results show that delayed detached eddy simulation is a suitable computational model for flow noise simulations.

Numerical investigation on the characteristics of underbody aerodynamic noise sources in electric vehicles

As the wind noise caused by the upper body is gradually controlled, the influence of high-speed underbody airflow on the interior noise of electric vehicles becomes increasingly prominent. The method involves the combined application of the Finite Volume Method (FVM) and Finite Element Analysis (FEA) to compute the aerodynamic noise inside a real vehicle model induced by high-speed airflow. A numerical simulation of the underbody wind noise in electric vehicles has been conducted to reveal the noise sources at the bottom of electric vehicles and cabin noise. Finally, the impact of side skirts and wind deflectors on chassis wind noise was evaluated.

Study on the distribution characteristics of TBL fluctuating pressure of a submerged conical-cylindrical structure

The fluctuating pressure within turbulent boundary layers (TBL) has garnered significant attention as a pivotal factor in generating hydrodynamic noise for underwater vehicles. This study employs numerical simulations to investigate the fluctuating pressure of a submerged conical-cylindrical structure, utilizing the Improved Delayed Detached Eddy Simulation (IDDES) method. This research delves into the spatiotemporal distribution characteristics of wall fluctuating pressure across various Reynolds numbers. Notably, the power spectral density (PSD) curve of TBL fluctuating pressure exhibits relative stability at lower frequencies, whereas it undergoes a rapid decline in the high-frequency range, following an inverse proportional trend with the power-law exponent of frequency. Moreover, the dimensionless migration velocity in the parallel mid-body segment is consistent with the TBL over a flat plate, while it is slightly smaller in the outflow segment.

Fidelity of Finite Element–Based Virtual Tire Assembly Models Used for Vehicle Noise, Vibration, and Harshness Structural-Borne Noise Performance Considering Vibrational Modal and Steady-State Dynamic Simulation

ABSTRACT The increasing presence of battery electric vehicles brings about new challenges to the noise, vibration, and harshness performance of tires. One of the new challenges involves the expansion of frequency range for structural-borne noise virtual predictions. Current standard virtual tire simplifies the tire geometry as an axisymmetric body, neglecting the effect of complex tread pattern. It is perceived that this simplification can lead to prediction error for a tire’s structural-borne noise performance at mid-frequency range (250∼500 Hz). This study investigates how different tread pattern representation affects the structural-borne noise prediction. This study uses linear, steady-state dynamics finite element simulations of a modified SAE J2710 test and traveling sinusoid test. The resulting frequency responses of the virtual tires and the computational time to obtain each frequency response are compared. The comparison shows that while including the 3D tread pattern does show some differences under certain conditions, it is not necessary to use this technique for every case, especially during the early evaluation stage.

Enhanced selective delayless subband algorithm independent of primary disturbance configuration for multi-channel active noise control system in vehicles

The selective delayless subband structure stands out as a promising algorithmic choice for the multi-channel active control of vehicle interior noise, particularly in the context of road noise. This type of algorithm reduces the eigenvalue spread of the autocorrelation matrix of the signal by decomposing the signal into subbands, and the desired subbands are activated selectively, thus achieving a significant performance improvement while consuming less computational resources compared with the traditional fullband algorithms. Nevertheless, the effectiveness of the subband algorithm appears to be closely tied to the configuration of the primary disturbance signal. In cases where the primary disturbance signal encompasses both broadband and tonal components, the performance advantage of the subband algorithm becomes constrained. In this paper, we conduct a thorough comparative analysis of two extensively employed subband algorithms, namely the Morgan and the Milani methods, through simulations employing data obtained from a multi-channel active noise control (ANC) headrest system. The results indicate that the Morgan method outperforms the Milani method when configured optimally. Subsequently, we propose an enhanced version of the subband algorithm based on the Morgan method. The enhanced algorithm incorporates an additional sinusoidal noise canceller (SNC) subsystem and a narrowband active noise control (NANC) subsystem based on local secondary path modeling to address tonal components, while the selective subband structure is employed for controlling broadband components. In addition, the computational complexity of the algorithm is analyzed. The effectiveness of the proposed algorithm is validated through numerous simulations and the ANC tests conducted on an actual vehicle utilizing the multi-channel ANC headrest system. The performance of the proposed algorithm surpasses that of traditional selective subband and fullband algorithms, and balanced binaural noise reduction is achieved.

The Use of Wind Turbine Blades to Build Road Noise Barriers as an Example of a Circular Economy Model.

This project's objective was to create a circular economy in the composites sector by examining the possibility of using wind turbine blade composite materials to construct noise-absorbing barriers for roads. The possibility of constructing road noise barrier panels from components obtained from turbine blades was conceptually examined, and the geometry and construction of wind turbine blades were evaluated for their suitability as filler components for panels. The tensile strength parameters of two types of composites made from windmill blades-a solid composite and a sandwich type-were established based on material tests. The strength of the composite elements cut from a windmill propeller was analyzed, and a three-dimensional numerical model was created using the finite element method. The strength values of the composite used to construct the noise barriers were compared with the stresses resulting from loads operating on the road noise barriers, as determined in compliance with current standards. It was discovered that acoustic screens composed of composite materials derived from wind turbine blades may withstand loads associated with wind pressure and vehicle traffic with sufficient resistance. In order to evaluate the environmental benefits resulting from the use of composite material made from wind turbine blades to make noise barriers, this study presents the values of the embodied energy and embodied carbon for several types of road noise barriers using life cycle assessment.

Investigation of social change in cities after participation in cittaslow union in Ordu-Perşembe district

This study presents a case study of the social changes brought about by participation in the Cittaslow Union in cities. The research focuses on the Perşembe district of Ordu province and aims to analyze the effects of Cittaslow on the social structure. Data collection involved the use of 100 valid surveys. The results indicate that significant social changes occurred in the Perşembe district following its participation in the Cittaslow Union. Surveys and observations show an increase in tourism activities. This is due to heightened public awareness, which has been brought about by increased official institutional efforts to inform about Cittaslow. Furthermore, the Cittaslow Union's participation in Perşembe district has resulted in the wider availability of locally sourced food, increased promotion of cycling, and a reduction in vehicle noise pollution. Furthermore, the Cittaslow Union's participation in Perşembe district has resulted in the wider availability of locally sourced food, increased promotion of cycling, and a reduction in vehicle noise pollution. These changes have had a positive impact on the district's quality of life and social structure. The community has adopted a more sustainable and participatory lifestyle because of the Union's involvement. It can be inferred that the city has benefited from the approach. The identified changes demonstrate that participation in the Cittaslow Union in the Perşembe district has positive effects on the adoption of a sustainable and participatory lifestyle within the community. This study on the effects of the Cittaslow Union in the Perşembe district can be considered an important step in promoting sustainability and social participation in cities.

Optimization of Anti-Skid and Noise Reduction Performance of Cement Concrete Pavement with Different Grooved and Dragged Textures

Cement concrete pavements are crucial to urban infrastructure, significantly influencing road safety and environmental sustainability with their anti-skid and noise reduction properties. However, while texturing techniques like transverse grooving have been widely adopted to enhance skid resistance, they may inadvertently increase road noise. This study addressed the critical need to optimize pavement textures to balance improved skid resistance with noise reduction. Tests were conducted to assess the influence of surface texture on skid resistance and noise, exploring the relationship between texture attributes and their performance in these areas. The investigation examined the effects of texture representation methods, mean profile depth, and the high-speed sideway force coefficient (SFC) on noise intensity and pavement skid resistance. The findings revealed that transverse grooves significantly improved the SFC, enhancing skid resistance. In contrast, longitudinal burlap drag, through its micro- and macro-texture adjustments, effectively reduced vibration frequencies between the tire and pavement, thus mitigating noise. Utilizing the TOPSIS multi-objective optimization framework, an optimization model for pavement textures was developed to augment skid resistance and noise reduction at varying speeds. The results indicated that at 60 km/h, an optimal balance of groove width, depth, and spacing yielded superior skid resistance with a minimal noise increase. At 80 km/h, increased groove spacing and depth were shown to effectively decrease noise while maintaining efficient water evacuation. The optimal pavement texture design must consider the specific context, including traffic volume, vehicle types, and operating speeds. This study provides essential guidance for optimizing urban cement concrete pavement textures, aiming to diminish traffic noise and bolster road safety.

Rear Axle Whine Reduction by Gear Contact Patch Optimization

In-cab whine is a highly annoying phenomena in all the category of vehicles. The in-cab noise of passenger vehicle with Rear Wheel Drive ( RWD) considered for this study consist of axle whine noise. The whine noise is heard at multiple speeds during Wide Open Throttle (WOT) as well as coasting. To resolve the issue of whine noise, series of measurement are carried out to identify the source and transfer path of the whine. The noise measurement revealed that rear axle pinion mesh order is responsible for in-cab whine. It is confirmed through measurement that the whine is structure borne. The order based operational deflections shapes of rear axle show excessive vibration on differential nose in affected speed zones. It is thus learnt that whine is due to poor contact pattern of pinion and crown wheel of the rear axle. The three resonances in operation range amplify this mesh order resulting in whine. It is decided to work on noise source i.e. gear rather than transfer path. The hypoid gear design is optimized through Tooth Contact Analysis (TCA). The lapping and heat treatment processes of gear manufacturing are modified. The contact pattern of optimized gear is identified on gear tester machine. Significant improvement is observed in contact pattern. The in-cab noise measurement is carried out with optimized hypoid gear and it is found that the whine is completely eliminated.
 Keywords: Rear axle, Whine reduction, Gear contact, Patch optimization, Rear Wheel Drive, Whine Source, Vibration on Transfer Paths, Noise Generation, Hypoid Gear, Heat Treatment

A Feedback Active Control Approach to Road Noise Based on a Single Microphone Sensor to Improve Automotive Cabin Sound Comfort.

Tire-road noise deteriorates the sound quality of a vehicle's interior and affects the driving safety and comfort. Obtaining low interior noise is a challenge for passenger car manufacturers. Traditional passive noise control (PNC) is efficient for canceling high frequency noise but not useful for low frequency noise, while active noise control (ANC), according to the residual error signal, can generate an anti-noise signal to reduce the original noise. Most research has focused on improving the control effect for a feedforward ANC system. However, this paper emphasizes a feedback ANC system based on a signal microphone sensor. There are two main contributions in this study to improve automotive cabin sound comfort. One is that the algorithm of the feedback ANC system using a single microphone sensor without a reference noise signal is proposed based on the Filtered-x Least Mean Square method. The other is that the algorithm applies additive random noise online to estimate the secondary path model. A simulation was implemented based on measured real road noise data, and the simulation results indicate that the proposed feedback ANC system with the single microphone sensor can effectively attenuate road noise. This study shows the feasibility of applying a feedback ANC system in automobiles to increase the cabin sound quality.

Methods of detection and localization of the sources of noise and vibration on car gearboxes: a review

One of the primary sources of noise and vibration in automobiles is gearboxes. Shafts, gears, and bearings are the main causes of noise and vibration in vehicle gearboxes. Various studies have reported that vibrations’ root cause is bearing excitation. Besides bearing fatal defects or extreme structure resonance amplification, gear mesh is the primary source of high-frequency vibration and noise, even in newly built units. Gear damage detection is frequently crucial in automotive gearboxes and vehicle safety. Furthermore, vibrations caused by shaft imbalances, shaft misalignments, and other factors can cause noise and vibrations in the drivetrain's transfer path. In addition, the vibration of an automobile gearbox is closely related to poor design, construction quality, and production accuracy. This paper reviewed previous research and methods on car gearboxes for conventional vehicles. It was obvious that frequency analysis and order analysis were commonly used in noise and vibration analysis on car gearboxes. Envelope analysis is usually used to analyze bearing faults. Finally, rolling-element bearing diagnostic techniques were also reviewed.

Tuning user-defined pavements in CNOSSOS-EU towards reliable estimates of road noise exposure

Low-noise pavements (LNPs) are among the most frequently used measures to mitigate road traffic noise. CNOSSOS-EU model enables improved predictions of noise exposure by customizing surface coefficients. However, accurately estimating their benefits to citizens remains a challenge. Specific LNPs can be defined by the user, but their calibration remains difficult, with different approaches in literature. Using standard roadside measurements and the recent Urban Statistical Pass-By methodology, this study presents a procedure for tuning user-defined coefficients of pavements in a real-world scenario. Test cases results are assessed against reference scenarios to evaluate the population exposure differences and reduction of potential harmful effects. The procedure can be a valuable instrument in aiding action plans in compliance with the 2002/49/EC Directive. The work also highlights the need to assess the acoustical characteristics of LNPs to effectively evaluate health benefits, as well as the need for comprehensive studies defining the exact characteristics of LNPs.

Hybrid Electric Vehicle Powertrain Mounting System Optimization Based on Cross-Industry Standard Process for Data Mining

The meticulously engineered powertrain mounting system of hybrid electric vehicles plays a critical role in minimizing vehicle vibrations and noise, thereby enhancing the longevity of vital powertrain components. However, developing and designing such a system demands substantial time and financial investments due to intricate analysis and modeling requirements. To tackle this challenge, this study integrates data mining technology into the design and optimization processes of the powertrain mount system. The research focuses on the powertrain mounting system of a transverse four-cylinder hybrid electric vehicle, employing the CRISP-DM (Cross-Industry Standard Process for Data Mining) methodology to establish a data-mining prediction model for mounting stiffness. This model utilizes three data mining algorithms—Multi-SVR, MRTs, and MLPR—to assess their predictive accuracy concerning mounting system stiffness estimation. A comparative analysis reveals that the MRTs algorithm outperforms others as the most effective prediction model. The proposed predictive model elucidates the quantifiable correlation between vibration isolation performance and installation stiffness, overcoming complexities associated with traditional modeling approaches. Applying this model in powertrain mounting system design showcases the efficacy of the CRISP-DM-based approach, significantly enhancing design efficiency without compromising prediction accuracy.

Acoustic data detection in large-scale emergency vehicle sirens and road noise dataset

This paper presents a novel deep learning model called Self-Attention Layer within a Convolutional Neural Network (SACNN), specifically designed for detecting acoustic data in extensive datasets containing emergency vehicle sirens and road noise. SACNN leverages a combination of EfficientNet and One Dimensional Convolutional Neural Networks (1D_CNN) to improve the precision and efficiency of detection. The dataset comprises 3-second WAV-format audio files categorized into Emergency Vehicles (Ambulance and Firetruck sirens) and Traffic (plain traffic sounds), with each category having 200 sound files and their corresponding 200 spectrogram images per audio file. Experimental results demonstrate SACNN's superior performance across various metrics, including accuracy, precision, recall, and F1 score, while also achieving notable advancements in computational efficiency. The research addresses the need for more effective solutions in the domain of emergency vehicle siren and road noise detection by introducing SACNN as a cutting-edge solution. By integrating EfficientNet and 1D_CNN, SACNN surpasses existing models in accuracy and computational efficiency. Comparative analysis with EfficientNet and 1D_CNN using a large-scale dataset validates SACNN's superior performance, with an average accuracy, precision, recall, and F1 score of 1.00. Additionally, SACNN exhibits the highest computational efficiency, averaging 0.20883 s per sample. These findings highlight SACNN's efficacy in detecting and classifying emergency vehicle sirens and road noise in large-scale datasets, with implications for traffic management, public safety, and noise pollution monitoring. SACNN offers the potential for constructing real-time acoustic data detection systems.

Optimized road noise asphalt pavement technologies

From a medical point of view, noise has long been recognized as a stress factor for humans. A high level of noise makes it difficult to concentrate, creates not only stress but also health problems for the ears, and also has a damaging effect on the cardiovascular and endocrine systems - noise makes you sick! Road traffic accounts for a significant share of total noise, especially in conurbations. In order to effectively reduce noise emissions, surface courses can be installed as road surfaces that generate particularly little noise in interaction with the vehicle tyre. The road surface must therefore contribute to reducing traffic noise at the source.

The effect of angle of incidence on exterior façade isolation

A common acoustical task is the design and specification of the acoustical performance of the exterior façade system to protect building occupants from road and railroad noise. This involves calculating the outdoor-to-indoor noise reduction of the façade. The incident sound wave from a roadway will often approximate a plane wave from a specific angle of incidence, but the only data usually available is the diffuse field transmission loss of the assemblies as measured in the laboratory. While it is understood that there can be significant differences between the transmission loss at a given angle of incidence compared to the diffuse field value, a detailed and quantitative understanding of the effect is lacking. Measuring the transmission loss from plane waves at varying angles of incidence is difficult, and a combination of theoretical analysis and field measurements may allow a better understanding of the relationship and hence more accurate calculations of the interior noise level from transportation sources. The literature is reviewed, and data from field measurements is analyzed to begin to evaluate this effect.

Transit-oriented development: A case study of exterior-to-interior noise control for buildings near transit and highway noise sources

A case study of acoustical design for mixed-used, transit-oriented development is presented. The project is two, six-story mixed-used residential buildings near a rapid transit station and heavily traveled elevated highway in the San Francisco Bay Area. The buildings are metal frame construction over concrete podiums. The California Building Code requires the building shell to be designed to provide interior noise from exterior noise sources not to exceed 45 dBA Ldn. Exterior noise due to trains and buses serving the transit station, and traffic on the elevated highway, required high sound attenuating windows and acoustically rated walls and roofs. Initially, none of the exterior wall assemblies included batt insulation in the stud cavities, only continuous rigid insulation behind the façade. Modeling was done to compare the exterior wall assemblies with and without batt insulation in the stud cavities combined with various window configurations. Estimates of the building shell transmission loss are presented along with a summary of noise control recommendations for building roof, windows, and doors.

Silencing the rolling thunder: An almost unthinkable acoustic isolation facade solution

Situated along a popular motorcycle route, the Lindemann Performing Arts Center at Brown University posed a unique challenge to its design team — isolating the performance space from external road noise while adhering to the demanding RC 15 performance standard. This presentation provides a comprehensive exploration of the intricate development and testing of a robust yet relatively lightweight acoustic isolation façade system. The ultimate approach employed unconventional damping methods, ensuring compliance with dew point requirements. The paper delves into the nuances of the design process, with a focus on key elements such as glazing systems, roofing solutions, access doors, and gypsum buildups that push the boundaries of conventional construction, challenging the possible maximum length of a drywall fastener. Attendees will gain valuable insights into the innovative strategies implemented to achieve effective acoustic isolation without compromising the high-performance standards demanded by the Lindemann Performing Arts Center. This presentation serves as a valuable case study, offering a deeper understanding of the intersection between architecture, acoustics, and the practical challenges encountered in the design of performance spaces.

Sound levels of the UVU pedestrian bridge

Utah Valley University provides a pedestrian bridge to travel from a train station to the school over Interstate-15. Due to traffic noise, people using the bridge could be exposed to sound levels that damage their hearing. Sound level measurements have been made at several locations on the bridge with two different instruments, the first being an Extech (Knoxville, USA) SL400 noise dosimeter and the other being a Larson Davis (Depew, USA) 831C sound level meter. Sound levels have ranged from 55 to 102 dB, depending on time of day and location on the bridge. In addition to our experimental results a COMSOL model was also developed to simulate the interactions of the freeway noise with the bridge, demonstrating how the geometry of the bridge affects the noise exposure of pedestrians. The Occupational Safety and Health Administration (OSHA) limit for non-occupational noise exposure of 100 dB is 15 minutes, suggesting that pedestrians that linger on the bridge could be exposed to damaging levels of sound. This research seeks to better understand and quantify the noise levels that pedestrians experience on the bridge.

A psychoacoustic test on the effect of masking on annoyance to urban air mobility vehicle noise

Urban Air Mobility (UAM) vehicles have a large range of designs and configurations that lead to new noise characteristics and potentially different perceptual responses when compared to traditional aircraft. In addition, UAM vehicles are expected to operate around and within densely populated regions where the presence of ambient background noise is often present. Strategically, this can be leveraged to inform vehicle design and operations to partially or completely mask UAM noise, allowing for mitigation of negative responses and an increased number of allowed operations. A psychoacoustic test was conducted to investigate how masking effects can influence the annoyance response to a low frequency harmonic tone complex (80-320 Hz). To do this, five test subjects compared their annoyance response to the low frequency tonal noise with a higher frequency broadband noise (10 dB down bandwidth between 300 and 2000 Hz), with and without a masking noise present. Detection thresholds were also measured for both sounds to help fit a model to the data. Although the effect of masking on annoyance is complex, results indicate that for some individuals, masking leads to a lower annoyance than the sound level alone would predict.