Browse Topic: Noise, Vibration, and Harshness (NVH)

Items (9,513)

Evaluation of Static and Dynamic stiffness of rubber grommet by experimental and FEA method

2025-01-0274To be published on 07/02/2025

Vibration control is most important in automotive applications and generally rubbers are used to dampen these vibrations due to their inherent nature and low-cost manufacturing methods. Now to select a rubber material shore hardness is considered in engineering applications, but to additionally control the behaviour we need to understand its static and dynamic stiffness. These values help to determine the vibration isolation obtained by these rubbers. In this paper, we will discuss methods to calculate the static and dynamic stiffness of rubber grommets using experimental methods and FEA modelling. As elastomers have non-linear material properties various material modelling techniques in FEA are used to capture multiple phenomena like creep, fatigue and dynamic conditions. Rubber compounding is used to improve the physical and chemical properties which in turn would give desirable linear characteristics. Certain guidelines and thumb rules are used in the rubber industry for different

Khamkar, Prasad Subhash, Gaikwad, Vikrant C

Optimisation of Rotor Skewing of a Yokeless And Segmented Armature Axial Flux Machine

2025-01-0311To be published on 07/02/2025

This paper presents an optimization of rotor skewing of an Axial Flux Machine (AFM) in a Yokeless And Segmented Armature (YASA) design in the torque-speed characteristics diagram. AFM have advantages regarding a compact design and high torque density compared to other variants of permanent magnet machines. The drive train Noise, Vibration and Harshness (NVH) performance is influenced by cogging torque, magnetic torque ripple and tooth forces. While the axial skewing of rotors in radial flux machines (RFM) has already been extensively studied to minimize these magnetic excitations, this represents a target value for optimizations in AFM. Optimizations are carried out and validated using 2D and 3D finite-element (FE) models. The 2D model combines multiple 2D slices but lacks accuracy because an insufficient inclusion of 3D effects. The 3D model allows to obtain a noticeable reduction by more than 30% of the dominant torque harmonic amplitudes over the whole torque-speed range in

Müller, Karsten, Maisch, Hannes, De Gersem, Herbert, Burkhardt, Yves

Noise Management in Electric Vehicle Compressors for Superior Cabin Comfort

2025-01-0191To be published on 06/16/2025

“This research addresses the issue of noise, vibration, and harshness (NVH) in electric buses, which can hinder their widespread adoption despite their environmental benefits. With the absence of traditional engines, NVH control in electric vehicles focuses on auxiliary components like the air compressor. In this study, the air compressor was identified as a major source of vibration, causing harsh contact between its oil sump and mounting bracket. Analyzing the vibrations revealed that the sump and bracket were not moving freely, increasing noise. Modifying the bracket design to allow more movement between the components successfully reduced both noise and vibration. The paper details the experimental process, findings, and structural damping methods to mitigate NVH in electric buses”.

Paroche, Sonu, Patel, Shubhanshi, Patidar, Ashok Kumar

A Pich Shift Synthesis Algorithm for Electric Vehicle Sound Based on Quadratic Interpolation and Continuous Sample Indexing

2025-01-0254To be published on 06/16/2025

The electric vehicle driveline generates less vibration and noise compared to a conventional internal combustion engine vehicle, making it hard-er for the driver to perceive the vehicle’s operating status through driveline sounds, thereby diminishing driving engagement and experience. To compensate for the absence of engine sound in EV drivelines, Active Sound Design (ASD) technology has become a crucial method for drivetrain sound enhancement, with sound synthesis algorithms playing a key role in this process. Although pitch-shifting algorithms based on frequency variation principles can synthesize engine sounds, they suffer from spectral leakage and stuttering caused by sound splicing. To ad-dress these issues, a pitch-shifting synthesis algorithm (QCPS) is proposed in this paper, which combines a quadratic interpolation method with a continuous audio sample indexing strategy. First, the frequency variation coefficient of the sound is calculated. Based on this coefficient

Liu, Dezhu, Xie, Liping, Liu, Zhien, Lu, Chihua

NVH Improvement of Transmission Electric Oil Pump with Uneven Pitch Control

2025-01-0252To be published on 06/16/2025

Acoustic noise and vibration are always main issues to overcome in electric oil pumps for gearboxes in HEV and BEV. This paper introduces a noise reduction control method of electric oil pump in wet-type dual clutch transmissions. This paper proposes an uneven pitch control for electric oil pumps. For the noise reduction of vane pumps, mechanical arrangements of uneven pitch vain angle are widely used. However, the tooth angle of gear-type pumps should be even mechanically. The proposed uneven pitch control provides similar effects of the mechanical uneven pitch arrangement by instantaneous motor torque controls of the electric oil pump which cannot have uneven pitch mechanically. The magnitude of motor torque for each pump tooth is determined by an uneven pitch formula which is widely used for mechanical vane pumps in previous study and patents. A formula for the shape of motor torque is proposed by analyzing pressure fluctuations of pump as a combination of trigonometric and

Choi, Chinchul, Kim, Jongbeom

Sound Granular Synthesis Method for Science Fiction Sound Quality of Electric Vehicles

2025-01-0253To be published on 06/16/2025

Since the powertrain systems of electric vehicles (EVs) lack the traditional engine sound, their NVH performance differs from that of conventional fuel-powered vehicles, making the use of active sound design (ASD) systems increasingly common to provide compensatory sound. With the increasing demand for ASD systems, sci-fi sounds are emerging as a design direction to enhance the acoustic feedback of powertrain systems and to elevate the futuristic and immersive driving experience of vehicles. A method for generating sci-fi soundscapes using a granular synthesis algorithm is proposed in this paper. First, a sci-fi sound is designed based on the characteristics of sci-fi sounds, which serves as the target sound for the synthesis algorithm. Then, it is proposed that sound grains are generated using the adaptive main frequency method, and granular synthesis is achieved through the overlap-and-add (OLA) method. In addition, a method for optimizing the composite cosine window function based

Liu, Dezhu, Liu, Zhien, Xie, Liping, Lu, Chihua

Numerical Simulation and Parametric Optimization of Engine/Powertrain Mounts: Identifying Key Design Variables to Reduce NVH Noise

2025-01-0251To be published on 06/16/2025

Abstract: Introduction: Engine and powertrain mounts are vital for isolating vibrations and reducing the transmission of Noise, Vibration, and Harshness (NVH) from the engine to the vehicle structure. Despite technological advancements, addressing NVH issues related to tribological factors continues to pose significant challenges in automotive engineering. Aim: This study aims to systematically identify and optimize design parameters of engine/powertrain mounts to minimize NVH levels using CAE tools and parametric optimization techniques in Abaqus and Isight, respectively. Purpose: The purpose of this research is to investigate the correlation between various design parameters of powertrain mounts and their impact on NVH characteristics. Specific attention is focused on noises such as clunking, banging, or thumping that emerge from the engine bay under dynamic conditions like acceleration, braking, or turning. These sounds often occur as the engine moves excessively due to worn mounts

Ganesan, Karthikeyan

Acoustic Evaluation of Fiber-Based Materials for Engine Bay Applications

2025-01-0115To be published on 05/05/2025

A newly formulated fiber-based material was developed to offer a cleaner, recyclable alternative to foam-based vehicle acoustic products. The fiber-based material was designed to be used in multiple vehicle acoustic applications, with different blends of the material available depending on the application. It performs well as an engine bay sound absorber due to its high heat tolerance and good absorption performance. A study was conducted to evaluate the sound absorption performance of this fiber-based material, specifically the engine bay blends, in comparison to that of current foam-based products. The results from this study show that the sound absorption performance of this new fiber-based material can match that of current foam-based materials while providing a recyclable product unlike the foam.

Krugh, Jack

Metamaterial application to automotive glass for vibration reduction and reduced noise transmission

2025-01-0119To be published on 05/05/2025

A metamaterial which, attached to the edge of a panel, reduces vibration results in reduced noise transmission into a vehicle. In this particular case, the metamaterial is designed to be attached to the edge of a glass panel and can reduce panel vibration and noise transmission due to wind or other sources into the vehicle interior. Acoustic transmission loss and panel vibration assessments show the benefit of this approach.

Sorenson, Steve, Li, Xiaopeng, Moore, Jaime, Robison, Scott

Tire simulation to optimize road noise

2025-01-0111To be published on 05/05/2025

Tires have a significant impact on vehicle road noise. In the past, tire development has been driven by testing that is costly and time-consuming. Simulation approaches are becoming more important as the need for NVH performance requirements rises and vehicle development cycles get shorter. Therefore, simulation techniques should be used to tires at an early stage. Among various road noise, the noise of 80~160 Hz is easily felt when driving on the rough road, and this noise has a great relationship with the tire structural design. How to improve the road noise problem through tire simulation has become an important issue, so this paper puts forward the concept of virtual tire design and clarifies the responsibility of automotive enterprises and tire suppliers. In virtual tire design or tuning, an appropriate tire model is crucial for road noise performance. The CDtire model can meet the requirements, so in this article, CDtire is used to improve road noise at 80-120Hz. To obtain an

Zhang, Ben, Yu Sr, Jing, Chen, Qimiao, Liu, Xianchen, Gu, Perry

NVH Improvement of BEV transmission using housing modal analysis co-relation and design optimization

2025-01-0106To be published on 05/05/2025

Battery Electric Vehicles (BEVs) are extremely sensitive in terms of NVH requirements. While the engine is being replaced with an almost silent electric motor, the transmission noise appears persistent and demands more silent transmission. This has raised demand for improvement in design as well as manufacturing quality. Various innovations are being made to drive an improvement in the NVH. The following paper will discuss the improvement in NVH achieved through a design optimization of the housing using modal analysis. Firstly, the NVH results were co-related with the modal analysis and the cause for the dominant peak in amplitude of the NVH graph associated with the housing modes were mapped. A simple Excel based correlation matrix is used to map the list of all Eigenfrequencies of housing and its corresponding gear tooth frequency. Further optimization is done in housing design to defer the modal frequencies and another NVH test was run. It was proven that housing design

Pingale, Abhijeet Satish, Deshpande, Prasannakumar

Vibration refinement of two wheeler sub chassis and aesthetic parts due to engine unbalanced excitation forces

2025-01-0113To be published on 05/05/2025

Two wheelers are important and essential transportation mode in India. Designing a motorcycle with better riding comfort and minimal vibration are thus a major challenge for engineers now a day. Engine and road excitations are two sources of vibration acting on motor bike or scooter. These vibrations are transmitted to chassis, sub chassis, aesthetic parts and then to the rider and pillion. Unwanted vibrations will create discomfort to the rider/pillion as well as produces noises and hence needs to be minimized. This study is focused on diagnosis and control of output vibration responses of sub chassis/aesthetic parts due to engine unbalanced excitation forces. There are numerous parameters of motor bike/ scooter that govern the vibration responses of sub chassis/ aesthetic parts. Engine unbalanced inertia force characteristics and their transmission to rider and pillion has been studied and reported here. Environmental benefits demands for a complete NVH refinement for lesser

Khare, Saharash

Identification and Evaluation of Passthroughs That Affect the Acoustic Performance of a Dash System

2025-01-0121To be published on 05/05/2025

This paper discusses a systematic process that was developed to evaluate the acoustic performance of a production electric vehicle dash system. The production dash panel was tested under different configurations to understand the importance of passthroughs in the acoustics of the dash system. Results show that often the performance of the passthroughs strongly affects the overall performance of the dash system and this may become the limiting factor to increase the system STL. The dash with passthroughs was then extensively tested to understand the acoustic strength of different passthroughs and to understand how these passthroughs affect the overall performance of the dash system. Subsequently a test procedure based on flat panel tests was developed so the OEM can develop target values and the suppliers can provide test results of their passthroughs that are meaningful and useful to the OEM to help build an acoustically competitive vehicle.

Saha, Pranab, Baack, Gregory, Geissler, Christian, Kaluvakota, Srikanth, Pilz, Fernando

Feasibility of In-Situ Vehicle-Level Sound Transmission Loss Measurement to Guide Dash Pass-Through Grommet Selection

2025-01-0122To be published on 05/05/2025

Noise transmission through the vehicle dash panel plays a critical role in isolating passengers from noise sources within the motor bay of the vehicle. Grommets that contain electrical harness routing as well as HVAC lines are examples of dash panel pass-throughs that should be selected with care. Acoustic performance of these components is generally characterized in terms of measured quantities such as noise reduction (NR), sound transmission loss (STL), and insertion loss (IL). These measurements need to be carried out per SAE or ASTM standards in appropriate anechoic or reverberant chambers as this is important for consistency. This work explores an in-situ measurement of the grommet STL performance in the vehicle environment. It utilizes a repurposed vehicle with its cabin retrofitted to serve as an anechoic chamber and its frunk acting as a reverberant chamber. Results of this in-situ measurement are then compared to measurements following industry standards to discuss the

Joodi, Benjamin, Jayakumar, Vignesh, Chang, Michael, Geissler, Christian, Pilz, Fernando, Conklin, Chris

Hybrid 3D Sound Intensity and Simulation for Optimizing Acoustic Output of Truck Rear Axles

2025-01-0105To be published on 05/05/2025

This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations, focusing on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions. While the current application focuses on the truck's rear axle far-field radiation, the same method can be extended to predict in-cabin sound pressure, providing a versatile solution for many industrial problems.

Fernandez Comesana, Daniel, Vael, Georges, Robin, Xavier, Orselli, Joseph, Schmal, Jared

NVH improvement of the BEV transmission by altering bearing mounting arrangement.

2025-01-0104To be published on 05/05/2025

As per metaphor, “The squeaky wheel gets the grease” the transmission of battery electric vehicle (BEVs) gets topmost attention in terms of NVH improvement. While the engine is getting replaced with an almost silent electric motor, the transmission noise appears persistent and demands more silent transmission. This has raised demand for improvement in design as well as manufacturing quality. Various innovations are being done to drive an improvement in the NVH. Following paper will discuss the improvement in NVH achieved through a design innovation in the way bearings are installed and demonstrated a significant amount of improvement. We have used SMT MASTA used as a simulation tool to predict the expected results and a Transmission Dyno test bench in an anechoic chamber to test the NVH performance on physical sample. The innovation was done on a small single speed two stage reduction gearbox coupled with a 100 NM, 14000 RPM battery electric motor. Though the bearings have

Pingale, Abhijeet, Soni, Jaldeep

Virtual Gear Noise Analysis and Case Design Investigation for Concept Parallel Axis Drive Unit

2025-01-0102To be published on 05/05/2025

For electric vehicles, it is critical to develop drive units that produce a minimal amount of noise while meeting efficiency needs for a given application. Modern computational resources and accumulated experience allow for engineers to evaluate gear noise early in the development process and influence the design of the drive unit. This paper documents a high-fidelity virtual engineering approach to evaluate gear noise in a concept parallel axis drive unit and provide learnings to influence design of the external structure to improve NVH performance. By using the latest simulation tools to calculate and visualize the noise and vibration characteristics of the drive unit, designers and developers can implement design changes in optimization iterations to reduce noise and vibration. Gear harmonic response is firstly analyzed through a system model which considers structural deflection and misalignment, then a FE housing model is incorporated which is used for noise radiation evaluation

Lima, Luiz, Shi, Zhenghong, Xu, Hai, Reynolds, Craig, Miller, John

Study of sound and cabin touchpoint contributions to subjective perception of secondary ride

2025-01-0060To be published on 05/05/2025

Subjective perception of vehicle secondary ride is dependent on simultaneous touchpoint vibrations and audible inputs to the receiver. Standards such as ISO 2361 provide guidelines for objective measurement of human body thresholds to vibration. However, when a human experiences multiple vibration and aural input from the road, it becomes complicated to judge each individual contribution to the overall subjective perception. Additional factors such as ambient conditions, ergonomics, age, gender etc. also play a role. Secondary ride, which is defined as energy in the 10-30Hz range, is one such event that affects the customers perception of ride comfort and quality. The goal of this work is to develop a Noise Vibration and Harshness (NVH) simulator model of a vehicle driving over cleats and execute a secondary ride jury study. The aim of the study is to rank the contributions of each touch point input and sound to the overall subjective perception of secondary ride during these cleat

Jayakumar, Vignesh, Joodi, Benjamin, Geissler, Christian, Pilz, Fernando, Lynch, Luke, Conklin, Chris, Weilnau, Kelby, Hodgkins, Jeffrey

Evaluation of invariant structural and acoustic loads estimation methods to be used in vehicle platform development independent to the boundary conditions of load generation.

2025-01-0053To be published on 05/05/2025

Platform based vehicle development is standardized at Deere. The challenges of frontloading the integration effects of individual components within different platforms using predictive methods is key to shorten the development cycle. Components are generally characterized on test benches and can not directly be used to evaluate system performance. Invariant characterization is needed which is possible through techniques such as blocked loads estimation. To evaluate the applicability of such methods, the test stand based, and vehicle in-situ operational loads needs to be compared. The confident use of these methods for structural and acoustic loads enables the use of combination of test and simulation models of common components and system modules in a variety of products, enhancing early NVH response predictions. In this work, we compare a powertrain characterization in a vehicle and a test stand to assess the invariance of the operating mount structural loads as well as operating

Vesikar, Prasad Balkrishna, Edgington, Jason, Drabison II, John

Excavator exterior noise contribution analysis using angle-based operational acoustic load synthesis.

2025-01-0062To be published on 05/05/2025

Since earth moving machines (EMM) are subject to exterior noise (EN) regulations, OEMs need to develop mitigation solutions from an early design stage. It is challenging to predict solution effectiveness at early design stage. Excavators are distinct compared to other EMM as their upper frame rotate while keeping lower frame fixed. ISO 6395(2) or EC/2000/14(1) require EMMs to follow specific operating maneuvers where noise sources change their position, directivity, and speed along the operating cycle. These conditions pose challenges in performing noise contribution analysis as a function of angular position and operating condition. Authors successfully demonstrated Acoustic source quantification and contribution analysis for linearly moving EMMs. However, excavator pose data processing challenges due to angular motion. This work demonstrates the use of frequency domain ASQ for operational acoustic source quantification and use of frequency domain virtual prototype sub structuring

Vesikar, Prasad Balkrishna, Chaduvula, Prasanna, Aquino Arriaga, Adrian Antonio, Haynes, Timothy, Drabison II, John

Application of Hybrid SEA in Vehicle NV Package Optimization

2025-01-0050To be published on 05/05/2025

As India’s economy expands and road infrastructure improves, the number of car owners are expected to grow substantially in the coming years. This market potential has intensified competition among original equipment manufacturers (OEMs) to position their products with a focus on cost efficiency while delivering a premium user experience. Noise and Vibration (NV) performance is a critical differentiator in conveying a vehicle's premiumness, and as such, NV engineers must strategically balance the achievement of optimal acoustic performance with constraints on cost, mass, and development timelines. Traditionally, NV package optimization occurs at the prototype or advanced prototype stage, relying heavily on physical testing, which increases both cost and time to market. Furthermore, late-stage design changes amplify these challenges. To address these issues, this paper proposes the integration of Hybrid Statistical Energy Analysis (HSEA) into the early stages of vehicle development

Rai, Nitesh, Mehta, Makrand, Ravindran, Mugundaram

Cairene Car-Culture: How are Automobility and Social Behavior Linked to The Development of The Soundscape and Urban Fabric of Cairo.

2025-01-0069To be published on 05/05/2025

Cairo’s soundscape has witnessed changes due to the ongoing urban structure developments that accommodate the number of vehicles passing through the city. The soundscape produced by this growing automobility is affected not only by vehicles but also by their owners' behavior. Cairenes use their cars as a communication tool and an extension of private space. By viewing the vehicle as a component of the soundscape as well as a space that filters it, this study examines the synergy between social behavior, automobility, urban structure, and their interdependent relationship on the soundscape of Cairo. The study responds to literature elaborating on acoustic ecology, car culture, urban structure, and social behavior. The methodology applied in this study follows practice-based phenomenological research while documenting and reflecting on car cultural practices in Cairo from an aural perspective. Grounded theory contextualizes the analysis of archived audio and video material, semi

Abd El Naby, Abla Mohamed

Sound Design for Electric Vehicles: Enhancing Safety and User Experience Through Acoustic Vehicle Alerting System (AVAS)

2025-01-0068To be published on 05/05/2025

Silent engines are an excellent strategy to combat noise pollution. Still, they can pose risks for pedestrians who rely on auditory cues for safety and reduce driver awareness due to the absence of the familiar sounds of combustion engines. Sound design for silent engines not only tackles the above issues but goes beyond safety standards towards a user-centered approach by considering how users perceive and interpret sounds. This paper examines the evolving field of sound design for electric vehicles (EVs), focusing on Acoustic Vehicle Alerting Systems (AVAS). The study analyzes existing AVAS, classifying them into different groups according to their design characteristics, from technical concerns and approaches to aesthetic properties. Based on the proposed classification, an (adaptive) sound design methodology, and concept for AVAS are proposed based on state-of-the-art technologies and tools (APIs), like Wwise Automotive, and integration through a functional prototype within a

Rodrigues Ferraz Esteves, Ana Raquel, Campos Magalhães, Eduardo Miguel, Bernardes de Almeida, Gilberto

Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis

2025-01-0058To be published on 05/05/2025

To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.

Yang, Wenlong, Melo, Andre

A review on Electric Vehicle NVH challenges and recent trends

2025-01-0042To be published on 05/05/2025

Electric vehicles (EVs) present a distinct set of challenges in noise, vibration, and harshness (NVH) compared to traditional internal combustion engine (ICE) vehicles. As EVs operate with significantly reduced engine noise, other sources of noise, such as motor whine, power electronics, and road and wind noise, become more noticeable. This review paper explores the key NVH issues faced by EVs, including high-frequency tonal noise from electric motors, gear meshing, and vibrations. Additionally, it examines recent advancements and trends in NVH mitigation techniques, such as active noise control, improved material insulation, and advanced vibration isolation systems. Furthermore, this paper discusses the role of computational tools, simulation technologies, and testing methodologies in predicting and addressing NVH concerns in EVs. By providing an in-depth analysis of the challenges and the latest innovations, this review aims to contribute to the ongoing development of quieter and

Hazra, Sandip, Khan, Arkadip Amitava

Flow-Induced Noise Prediction and Validation of a Heavy-Duty Electric Vehicle's HVAC System Using the Lattice Boltzmann Method

2025-01-0057To be published on 05/05/2025

Within automobiles, the HVAC is a critical system to regulate the occupants’ thermal comfort. However, at its high operating speeds, it can contribute significantly to the overall sound levels perceived by the cabin occupants, impacting their experience. This is especially true in the case of electric vehicles due to their overall quieter operation. This work has the intention to validate HVAC noise predictions using computational fluid dynamics (CFD) simulations. In addition, CFD simulations provide detailed flow field insights which are essential to identify and rank the main noise sources, and it ultimately allows a better understanding of the physical mechanisms of noise generation on similar systems. These insights are very difficult, if not impossible, to obtain with physical testing and are key to designing a quiet and efficient HVAC system. Sound levels were measured experimentally at eight different locations inside of a Class-8 Nikola TRE hydrogen fuel cell electric semi

Ihi, Rafael, Fougere, Nicolas, Passador, Stephen, Woo, Sangbeom, Kim, James, Desouky, Mohamed

Subjective Development of EV Propulsion Noise to Drive Product Differentiation

2025-01-0067To be published on 05/05/2025

The frequency and amplitude content of powertrain noise is motor torque and speed dependent and tends to influence the driver’s subjective perception of the vehicle. This provides manufacturers with an opportunity to drive product differentiation through consideration of powertrain noise in early stages of the development cycles for electric vehicles (EVs). This paper focuses on the evaluation of customer preference and perception of acoustic feedback from different powertrain design options based on targeted powertrain orders and expected wind and road masking during high acceleration maneuvers. A jury study is used to explore customer feedback to a two-stage gearbox design with AC permanent magnet motor order combinations. The subjective influence of order spacing, dominant frequency content and the number of audible orders is studied to understand aural perspective product differentiation opportunities.

Joodi, Benjamin, Jayakumar, Vignesh, Conklin, Chris, Pilz, Fernando, Iyengar, Shashank, Weilnau, Kelby, Hodgkins, Jeffrey

Comprehensive Analysis and Optimization of Door Closing Sound Quality of a Heavy Truck

2025-01-0066To be published on 05/05/2025

Based on the objective and subjective experiment and finite element analysis, the influencing factors on the door closing sound quality of a heavy-duty truck is analyzed and optimized. Results show that the loudness and sharpness can be reduced apparently by increasing stiffness and damping of the door. The sound quality can be enhanced by increasing the pressure release area, which can decrease the air resistance of dooring closing. By adding holes on the inner liner and changing the pressure release location, the dooring closing air resistance is reduced from 289 Pa to 181 Pa. In terms of the rebound sound, the sound level is positively relative to the door closing force. Increasing the protrusion height and decreasing the stiffness of the vibration absorber of the handle can improve the rebound sound quality. Optimizing the absorbers on both ends and adding damping material can decrease the loudness by 47.8%, reduce the cavity sound, dismiss the trembling and improve the compact

Wang, Jian, Zhang, Yongshen, Feng, Lei, Xie, Chenhao, Lin, Jiewei, Sun, Changchun

Research on Shift Sound Quality Control Strategy for Active Sound Generation System in Automobile

2025-01-0019To be published on 05/05/2025

The active sound synthesis system of electric vehicles plays an important role in improving the sound perception and transmission of working condition information inside the vehicle. Nowadays, the active sound synthesis system inside the vehicle has become standard equipment in electric vehicles of major electric vehicle manufacturers to meet the user groups' demand for driving and riding experience. In order to enrich the driving experience of electric vehicles and automatic transmission vehicles, the sound performance should be close to the immersiveness and dynamic feedback brought by traditional manual transmission fuel vehicles. Based on the active sound synthesis algorithm in the car, this paper proposes an adaptive shift sound quality control strategy suitable for complex and changeable working conditions, with the aim of simulating the real shift sound of the engine. First, the motor speed offset is accurately calculated based on the transmission ratio of each gear of the

Zhou, Xilong, Liu, Zhien, Xie, Liping, Yu, Shangbo, Lu, Chihua, Gao, Xiang, Yongsheng, Wang

Active Control of Engine Order Noise for Heavy-duty Trucks: Using the Genetic Algorithm for the Optimization of Error Microphone Arrangement

2025-01-0013To be published on 05/05/2025

The arrangement of error microphones for a vehicle active noise control (ANC) system is no trivial work, especially for heavy-duty trucks due to the dilemma resulted from the large volume of the cab and the limited number of microphones accepted by most manufacturers in the auto industry. Most ANC developers resort to trial and error, which is not only a heavy workload given the amount of interested working conditions to be test, but also does not guarantee to yield the optimum noise cancellation performance. In this paper, the authors proposed an error microphone selection methodology using a genetic-algorithm (GA) -based mechanism. The target vehicle was a heavy-duty truck with a six-piston diesel engine, and two scenarios were particularly interested, i.e. driver & copilot and driver & one passenger sleeping on the berth. We first arranged eight microphones at different locations in the cab, five on the headrests, two on the B pillars and one at the head position of the sleeping

Wang, Jian, Ling, Zihong, Zhang, Zhe, Cai, DeHua, lv, Xiao, Zhang, Ming, Gao, GuoRan

Development of Offline Simulation Software for Active Sound Design in Electric Vehicles

2025-01-0017To be published on 05/05/2025

With the increasing adoption of electric vehicles (EVs), Active Sound Design (ASD) has emerged as a crucial method to enhance both the sound quality and driving experience, addressing the lack of distinctive engine sounds present in internal combustion vehicles. This paper presents an ASD offline simulation software developed on the MATLAB platform to address these challenges. The software integrates a vehicle dynamics model with three key sound synthesis algorithms: order synthesis, pitch shifting, and granular synthesis, allowing for comprehensive control strategy development, real-time sound playback, and rapid adjustment. The software consists of several functional modules, including configuration, order generator, pitch shifting, and granular synthesis interfaces, which support user-friendly operation and flexible sound parameter adjustments. Users can simulate different driving conditions and evaluate the acoustic performance of the ASD system in real time. The system also allows

Qian, Yushu, Xie, Liping, Xiong, Chenggang, Liu, Zhien

Plug-in hybrid and range extender NVH – Challenges and Solutions

2025-01-0101To be published on 05/05/2025

The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. While the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 reduction targets, hybridized propulsion solutions can play a vital role in the electrification strategy of vehicle manufacturers. Plug-in hybrid and range extender vehicles show unique NVH challenges due to their different possible operation modes. First, the paper outlines different driveline architectures for PHEV and range extenders. Given the multiple general architectures, as well as operation modes which typically occur for these vehicles, characterizations and source-path analysis of these vehicles can be more complicated than conventional vehicles. In the following steps, typical NVH related challenges are highlighted and potential solutions for NVH optimization are discussed. While the overall noise levels

Wellmann, Thomas, Ford, Alex, Pruetz, Jeffrey

Simulation of Pass-by Fan Noise Emissions and Advancing Test Regulations for Heavy-Duty Electric Vehicles

2025-01-0086To be published on 05/05/2025

The rapid adoption of electric vehicles (EVs) necessitates updates to the automotive testing standards, particularly for noise emission. This paper examines the vehicle-level noise emission testing of a Nikola Class 8 hydrogen fuel cell electric semi-truck and the component-level noise emission testing needed to create a predictive simulation model using Wave6 software. The physical, component-level noise emission testing focused on individual cooling fans in a semi-anechoic chamber to assess their isolated noise contributions. With this data, an initial model was developed using spatial gradient statistical energy analysis, which successfully predicted pass-by noise levels based on varying fan locations and speeds. Real-world pass-by testing confirmed the model's accuracy across different cooling fan speeds. By leveraging advanced simulation techniques, engineers aim to enhance the accuracy and reliability of pass-by noise predictions through cost-effective studies of architectural

Passador, Stephen, Woo, Sangbeom, Liu, Ting-Wei, De La Vega Alonso, Gerardo, Kim, James

Localisation of Ultra-short Sound Emissions from Automotive Components by Using the Sound Field Scanning Method

2025-01-0092To be published on 05/05/2025

Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from

Rittenschober, Thomas

Do EVs Snore?

2025-01-0074To be published on 05/05/2025

As EV and PHEV adoption continues to increase more people will have direct experiences with these quieter vehicles in their daily lives. Topics such as 'propulsion sound' via Active Sound Design (ASD) and bystander safety through Acoustic Vehicle Alerting Systems (AVAS) have been discussed widely for many, many years...but who is talking about Charging Noise? Charging noise is a less spoken about topic because most EV / PHEV owners will charge their vehicles at their home, in their garage or their driveway, overnight when they are sleeping. Because of that people do not think much about charging noise. But anyone who has plugged in their car overnight will tell you a strange cacophony of sounds come from the car...and some can be downright concerning. In this paper data from several production EVs were measured during their normal charging cycle. Binaural recordings made inside and outside the vehicle are analyzed using psychoacoustics metrics to see what sounds would cause the most

Marroquin, Marc, Bray, Wade

Fast noise prediction of an electric powertrain integrated in various vehicles

2025-01-0076To be published on 05/05/2025

The automotive industry's transition to electrification raises new challenges to maintain a comfortable acoustics environment both inside and outside the car. This paper presents an innovative way to make an early prediction of the overall sound of a vehicle at driver’s ear by mixing noise sources that can be simulated and noise sources that can be measured at component level. This hybrid approach combining Test and Simulation data helps make decisions in the early design phase by predicting the noise of one component integrated in the whole vehicle. For instance, Valeo, with the help of sound synthesis techniques, is able to predict the sound of an e-drive when it is combined with Rolling noise that varies depending on the vehicle speed and the car segments - more or less refined, from a dataset of multiple vehicles. Realistic signals could be generated and compared with actual acoustic measurement to validate the method.

Redon, Milan, Dendievel, Clement, Pluton, Matthias

Electric compressor integration noise influence in Battery Electric Vehicles

2025-01-0075To be published on 05/05/2025

Within the automotive industry’s shift to Battery Electric Vehicles, in order to meet the global zero emission target, thermal management systems are key aspects to address. For instance, vehicle cooling requirements are reinforced to take into account the cabin comfort as well as battery management performances. Consequently to the increased cooling requirements, the critical component that is the Electric Drive Compressor, must operate at higher speeds and refrigerant pressures to achieve these targets. This trend results in increased noise levels which might occur inside the car cabin and outside. In this paper, noise investigations were performed on different Battery Electric Vehicles to assess the behavior of the electric compressor within a temperature controlled environment. Then, the electric compressors alone were investigated on specific test benches with compressor load units. The vehicle level assessment highlighted significant noise differences between vehicles. Further

Bennouna, Saad, Yamayoshi, Itsukyo, Del Valle, Edward

Methodology for Sound Quality Metric Development

2025-01-0070To be published on 05/05/2025

Many individual technical descriptors exist to quantify and describe different kinds of acoustic phenomena. However, each only describes the technical aspects of a sound itself without considering any additional non-acoustic context. Human perception is greatly informed by this context. For example, humans have different expectations for the sound of an electric razor than they do for an internal combustion engine, despite both objects being able to be described by sound pressure level or a measure of roughness. No single technical descriptor alone works in all contexts as a gold standard that objectively determines whether a sound is “good.” Jury tests, however, are a great aid in gaining a measure of this context. When seeking to develop a meaningful quality index for the sounds of a device, it is often necessary to combine the perceptive information from the results of a jury test alongside one or more technical descriptors. The combination of perceptive data and technical

Thiede, Shane

Snap-fits evaluation for minimizing the Squeak & Rattle in Automotives

2025-01-0091To be published on 05/05/2025

The world of plastic products has been growing due to its versatile properties, which have become an intrinsic and fundamental part of the engineering of new products. The most important aspects contributing to this spectacular growth are the design and assembly, making sure that plastic parts are designed optimally. The safety requirements have been increased due to the safety ratings and thus interior parts must provide more absorption and protection to occupants. The main connection types used in the plastic parts are heat stakes and snap fits. The purpose of a good snap fit is not only to have a high retention effort but also to present ergonomic characteristics with low insertion and extraction effort because each part requires a different function. With the time-dependent loading the material will redistribute its internal energy thereby performing a time-related flow leading to reduced pretension thus decreasing stiffness. This paper presents an analytical and numerical method

Michael Stephan, Navin Estac Raja, C M, Mithun, Mohammed, Riyazuddin, R, Prasath

Optimization of HEV Vehicle’s Engine Modulated Noise

2025-01-0084To be published on 05/05/2025

One 1.5L Miller-cycle turbocharged four cylinder gasoline hybrid engine is installed on a certain hybrid vehicle. When accelerating at low to medium speeds with a small throttle, there is a "da da" knocking noise inside the car, which seriously affects the overall sound quality of the vehicle. By analyzing the vibration and noise data of the engine, it was found that the frequency of the abnormal knocking sound is 200-1000Hz, which presents a half order characteristic in the time domain, that is, one knocking occurs when the engine crankshaft rotates twice. Through Hilbert demodulation analysis of the vibration data in the problem frequency range, it was found that the knocking noise was modulated in the frequency domain, with a modulation frequency of half of the crankshaft rotation frequency. By building a fully flexible multi-body dynamic model of a hybrid powertrain and inputting the engine's cylinder pressure excitation, the combustion excitation is coupled with mechanical

Dan, Kong

Horn sound digital validation for ECE-R28 regulation compliance

2025-01-0008To be published on 05/05/2025

Every vehicle has to be certified by the concerned governing authority that it matches certain specified criteria laid out by the government for all vehicles made or imported into that country. Horn is one of the components that is tested for its function and sound level before a vehicle is approved for production and sale. Horn, which is an audible warning device, is used to warn others about the vehicle’s approach or presence or to call attention to some hazard. The vehicle horn must comply with the ECE-R28 regulation in the European market. Digital simulation of the horn is performed to validate the ECE-R28 regulation. In order to perform this, a finite element model of a cut model of a vehicle, which includes the horns and other components, is created. Fluid-structure coupled numerical estimation of the sound pressure level of the horn, with the appropriate boundary conditions, is performed at the desired location as per the ECE-R28 regulation. The simulation results thus obtained

Ramachandran, Balachandar, Raveendran, Roshin, Mondal, Arghya

Leveraging user feedback to optimize the tuning of EVSE models

2025-01-0020To be published on 05/05/2025

The implementation of active sound design models in vehicles requires precise tuning of synthetic sounds to harmonize with existing interior noise, driving conditions, and driver preferences. This tuning process is often time-consuming and intricate, especially facing various driving styles and preferences of target customers. Incorporating user feedback into the tuning process of Electric Vehicle Sound Enhancement (EVSE) offers a solution. A user-focused empirical test drive approach can be assessed, providing a comprehensive understanding of the EVSE characteristics and highlighting areas for improvement. Although effective, the process includes many manual tasks, such as transcribing driver comments, classifying feedback, and identifying clusters. By integrating driving simulator technology to the test drive assessment method and employing machine learning algorithms for evaluation, the EVSE workflow can be more seamlessly integrated. But do the simulated test drive results

Hank, Stefan, Kamp, Fabian, Gomes Lobato, Thiago Henrique

Global Vehicle Vibration Enhancement Using Circular Force Technology

2025-01-0015To be published on 05/05/2025

In addition to safety advantages, sound and vibration are being utilized to enhance the driver experience in Electric Vehicles (EVs). Significant interest and investment continue to grow in utilizing interior and exterior sound for pedestrian safety and driver awareness of vehicle state, as well as enabling a unique personal EV audio experience for brand recognition both inside and external to the vehicle. Several automakers are also using audio to simulate virtual gear shifting and as well as manual transmissions in EVs. According to several automotive industry articles and market research, the audio enhancements alone, without the vibration that drivers are accustomed to in combustion engine vehicles, are not sufficient to meet the engagement, excitement, and emotion that driving enthusiasts expect. In this paper, we introduce the use of new automotive high-force compact light-weight circular force generators for globally shaking vehicles. The technology was developed originally for

Norris, Mark A., Orzechowski, Jeffrey, Sanderson, Brad, Swanson, Douglas, Vantimmeren, Andrew

Correlated Beamforming Based on Deconvolution Methods for Identified Vehicle Exterior Wind Noise Sources and Interior Noise

2025-01-0025To be published on 05/05/2025

Sound source identification based on beamforming is widely used today as a spatial sound field visualization technology in wind tunnel experiments for vehicle development. However, the conventional beamforming technique has its inherent limitations. To improve the performance, three deconvolution methods CLEAN, CLEAN-SC and DAMAS were investigated. These algorithms were applied for the wind noise sources identification on a production car. After analysis of vehicle exterior wind noise sources distribution, to study the energetic contribution of identified exterior noise sources to interior noise, correlation analysis between them were conducted. The results show that, the algorithm CLEAN-SC based on spatial source coherence shows the outstanding capability to remove the sidelobes for the uncorrelated wind noise sources, while CLEAN and DAMAS which based on point spread function have definite limitations. In the application aspect, the main noise source outside vehicle is from the

He, Yinzhi, Shen, Henghao, Wu, Yu, Zhang, Lijun, Yang, Zhigang, Blumrich, Reinhard, Wiedemann, Jochen

Design of a Reactive-Style Muffler for a Formula SAE Race Car

2025-01-0024To be published on 05/05/2025

The noise generated by internal combustion engines, particularly in high-performance vehicles like Formula SAE race cars, presents a significant challenge in adhering to strict competition noise regulations. To address this issue, mufflers are essential for reducing acoustic emissions. This study focuses on the design, manufacturability, optimization, and validation of a reactive-style muffler specifically for a Formula SAE combustion competition car. The proposed muffler utilizes two chambers to generate destructive interference, targeting the two dominant exhaust frequencies of the Honda CBR600RR engine to maximize transmission loss and reduce noise levels below the SAE-mandated range of 103–110 dB(C). A 3D model of the muffler was developed using SolidWorks, capturing the precise geometries required for acoustic optimization. The exhaust noise and muffler performance were simulated using GT-Suite, allowing for an evaluation of noise attenuation across engine speeds. Experimental

Labao, Kai, Middleton, Nicholas, Nuszkowski, John

HV-Battery Impact on Car Body Acoustics and Damping Package Case Study of the Electric Vehicle

2025-01-0041To be published on 05/05/2025

Damping treatments are playing an important role in the definition of efficient acoustic packages for passenger cars with all types of propulsion systems. Many parts of the damping layout are identical for all vehicles including treatments of wheelhouses, spare wheel area, roof panels etc. However, there are some characteristics in car body acoustics associated with the presence of the battery in electric vehicles, which need to be considered in the definition of the efficient damping package. The presented paper investigates the impact of the HV-battery on interior noise related characteristics of the car body using laser scanning vibrometry and 3D acoustic intensity test methods. Findings are used in the subsequent optimization of the initial damping package resulting in various package proposals with different lightweight and acoustic requirements. New damping package variants are evaluated in the lab by laser vibrometry tests and the impact on interior noise is addressed by road

Unruh, Oliver, Gielok, Martin

Directivity driven simulation methodology for efficient Acoustic Encapsulation

2025-01-0048To be published on 05/05/2025

Noise Reduction at the source level is critical to achieve the overall vehicle level interior targets. This method presents a novel approach that integrates directivity analysis with simulation techniques to optimize acoustic encapsulation design for automotive sound sources to achieve the targeted radiation levels. The foundation for this methodology is to measure the angular distribution of sound pressure levels around the noise source so called Directivity, at every frequency of interest and determine the most effective Acoustic encapsulation to achieve the targeted sound radiation. Accurate measurement of directivity in physical testing with fine angular resolutions can be complex and expensive, this study utilizes numerical simulation techniques using FEA to mitigate the challenges in mid frequency range. The scope of the study is focused on mid frequency sound pressure levels between 500-2000 Hz, which are determined to be significant contributors to overall DU noise. The first

Kaluvakota, Srikanth, Ghaisas, Nikhil, Pilz, Fernando

Experimental Investigation into Modulated Aeroacoustic Cabin Noise arising from Unsteady Flow Conditions

2025-01-0029To be published on 05/05/2025

The unsteady wind conditions experienced by a vehicle whilst driving on the road are different to those typically experienced in the steady-flow wind tunnel development environment, due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. This paper presents an experimental approach using a large SUV-shaped vehicle to assess the effect of unsteady wind on the modulated noise performance, commonly used to evaluate unsteady wind noise characteristics. The contribution from different geometric modifications were also assessed. The approach is extended to assess the pressure distribution on the front side glass of the vehicle, caused by the aerodynamic interactions of the turbulent inflow in straight and yawed positions, to provide insight into the noise generation mechanisms and differences in behaviour between the two environments. The vehicle response to unsteady wind

Jamaluddin, Nur Syafiqah, Oettle, Nicholas, Staron, Domenic

Multi-Method Approach for car tailgate electric telescopic rod Noise: Detection, Characterization, and Prediction

2025-01-0038To be published on 05/05/2025

As the automotive industry moves towards greater intelligence, electric tailgate systems have seen widespread adoption, featuring remote control, obstacle detection, and intelligent opening functions that significantly enhance the user experience. The electric telescopic rod, as a key actuator, has drawn attention for its structural and transmission design. However, studies have shown that during actual operation, various noise issues arise with electric telescopic rods, affecting the sound quality and smoothness of the tailgate's opening and closing. This paper presents a noise detection and analysis study based on a bench test platform for a specific model of electric telescopic rod. Using a microphone to capture noise signals, three main types of noise were identified: high-frequency electromagnetic noise, low-frequency impact noise, and periodic structural noise. The study accurately detects high-frequency electromagnetic noise using wavelet packet energy feature extraction

Fan, Sibei, Wang, Siling, Zhu, Zhehui, Li, Lei, Qin, Jiade, Meng, Dejian, Pei, Kaikun

Tonal noise investigation of automotive HVAC systems : a hybrid method

2025-01-0027To be published on 05/05/2025

There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of

Bennouna, Saad, Alaoui, Mohamed, Henner, Manuel

Items per page:

1 – 50 of 9513