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

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Analysis Techniques for Racecar Data Acquisition [mms update 07.03.25]R-367To be published on 03/22/2099
Data acquisition has become an invaluable tool for establishing racecar - and car/driver - performance. Now that the ability exists to analyze each and every performance parameter for car and driver, accurate use of this data can provide a key advantage on the racetrack. This book provides a thorough overview of the varied methods for analyzing racecar data acquisition system outputs, with a focus on vehicle dynamics.
Segers, Jorge
Methods to Mitigate Tail Pipe Noise in Passenger Vehicles2018-01-12801/30/2026
The cold end of an exhaust system plays an important role in today’s passenger cars by reducing the engine noise and thus keeping a pleasant cabin room for optimum passenger comfort. However, due to vehicle layout constraints, it may be difficult to achieve a Muffler design which fulfills the required noise attenuation requirement. It becomes imperative to have an understanding of the different parameters that affect the overall tail pipe noise. In an automobile exhaust system, Exhaust Mufflers play a major role in noise reduction by helping in the attenuation of undesirable noises from the engine. The overall content of the tail pipe noise of an IC engine can be segregated into two categories - Order noise and Flow noise. Order noises are low frequency pressure pulses generated during the exhaust valve opening and closing in the engine combustion cycle. Flow noises are high frequency noises which are generated due to the flow of the exhaust gas and primarily depends on gas velocity
Vineeth, S., Chauhan, Vikram, Nanda, Aditya
Acoustic Assessment in a Small Displacement Diesel Engine2014-32-01291/30/2026
In the last years, the increasing concern for the environmental issues of IC engines has promoted the development of new strategies capable of reducing both pollutant emissions in atmosphere and noise radiation. Engines can produce different types of noise: 1) aerodynamic noise due to intake and exhaust systems and 2) surface radiated noise. Identification and analysis of noise sources are essential to evaluate the individual contribution (injection, combustion, piston slap, turbocharger, oil pump, valves) to the overall noise with the aim of selecting appropriate control strategies. Previous paper focused on the combustion related noise emission. The research activity aimed at diagnosing and controlling the combustion process via acoustic measurements. The optimal placement of the microphone was selected, where the signal was strongly correlated to the in-cylinder pressure development during the combustion process. Analysis and processing of the sound emission allowed the acoustic
Chiatti, Giancarlo, Recco, Erasmo, Chiavola, Ornella, Conforto, Silvia
A Scientific approach to identify the source of intermittent steering rattle noise and implementing the design solutions2026-26-03461/16/2026
Body-on-frame vehicles are well-regarded for their durability and off-road capabilities, but their structural design often makes them more vulnerable to noise, vibration, and harshness (NVH) issues. Vibrations originating from uneven roads are transmitted through the suspension and steering assemblies, sometimes resulting in rattles or other disturbances. These vibrations can be amplified by the inherent flexibility in the body-to-frame mounting system. In such vehicles, the steering system plays a critical role in driver comfort and is highly sensitive to vibrational inputs from the road surface, especially on coarse or uneven terrain. Occasionally, these inputs result in subtle rattle noises that are perceptible only to the driver and may not be detected under controlled testing environments. This poses a challenge for engineers trying to isolate and resolve such intermittent NVH phenomena. Identifying the source requires a combination of real-world driving evaluations, structural
Ramesh Chand, Karan Kumar, Gopinathan, Haridoss, Kabdal, Amit
Transforming Gear Manufacturing_ A Deep Learning Approach to Quality Prediction2026-26-06461/16/2026
The automotive industry is rapidly transitioning towards Industry 4.0, transforming vehicle manufacturing. To achieve a lower carbon footprint, it is crucial to minimize raw material wastage and energy consumption. Reducing component wastage, lead time, and automating gear manufacturing are key areas. Gear micro-geometry inspection is vital, as variations affect service life and NVH (Noise, Vibration, Harshness). Despite standards for permissible errors, manual evaluation is often needed.This subjective evaluation approach will have a possibility that a gear with undesired variations gets assembled into the product. These issues can be detected during NVH testing, leading to replacement of part and re-assembly thus increasing lead time. This generates a need for an automated system which could reduce the human intervention and perform the activity. This paper discusses methodologies to meet these requirements and achieve desired results. The research aims to develop a deep learning
Ramakrishnan, Gowtham Raj, Baheti, Palash, PR, Vaidyanathan, Durgude, Ranjit, Bathla, Archana, R, Greeshmita, V, Rangarajan
Refinement of Road Induced Steering Wheel Vibration in Electric Vehicle2026-26-03371/16/2026
Nowadays, customers expect excellent cabin insulation and superior ride comfort in electric vehicle. OEMs focuses on fine tuning the suspension system in electric vehicle to isolate the road shocks which finally offers superior ride quality. This paper focuses on the enhancing the ride comfort by reducing the steering wheel vibration which mainly originates due to road inputs. Higher steering wheel vibrations are perceived on the test vehicle when driven on rough road at the speed of 50 kmph. To determine the predominant force transfer path, Multi reference Transfer Path Analysis (MTPA) is performed on the front and rear suspension. Based on the finding from MTPA, various recommendations are explored and the effect of each modification is discussed. Apart from this, Operational Deflection Shape (ODS) analysis is carried out on the entire steering system to identify the deflection shape at the operating condition. Based on ODS findings, recommendations like dynamic stiffness
S, Nataraja Moorthy
Analysis and optimization of noise and vibrational performance of an e-axle2026-26-03401/16/2026
As the electric mobility landscape evolves, there is a growing emphasis on addressing the Noise, Vibration, and Harshness (NVH) challenges associated with electric drivetrains. The absence of an IC engine in EVs shifts the focus to other noise contributors such as gear meshing, electric machine operation, and structural vibrations. Despite the known influence of micro-geometry on gear dynamics, current optimization practices often rely on empirical adjustments or standard guidelines without fully utilizing advanced computational methods to predict and optimize NVH performance. There exists a pressing need for a systematic approach to analyse and optimize gear micro-geometry to reduce noise and vibration in high-speed e-axle applications. This research aims to bridge that gap by investigating the relationship between micro-geometry optimization and NVH characteristics of an e-axle. Through detailed modelling and optimization techniques, this research aims to identify optimal gear micro
Ankit, Priyadarshi, KULKARNI, KRISHNA, Momin, Vaseem
Assessment of Structure-borne Road Noise for Battery Electric Vehicle: Prediction and Improvement2026-26-03201/16/2026
In the absence of engine noise, road-induced noise has become a major concern specifically for Battery Electric Vehicles (BEVs), impacting Sound Pressure Level (SPL) for both drivers and passengers. Under the influence of random road load inputs, structural vibrations which transfer from road and tire to suspension to vehicle body, the cabin interior noise, particularly at lower frequencies, is significantly affected. To improve the road-induced low-frequency structure-borne noise behaviour, which frequently perceptible as ‘booming noises’, a study was carried out to assess predominant noise sources present in vehicle and to suggest refinements in reducing noise levels. By considering random excitations of road profile through tyre patch using CD-Tire model, vehicle interior noise was computed. Subsequently, to get insight of dynamic behaviour of vehicle, various diagnostic assessments to understand the influence from structure and paths were deployed. Major contributors from body
Paik, Dr. Suman, Raghuvanshi, Jayeshkumar, Chaudhari, Vishal Vasantrao, V, Radhika
Road noise improvement of a passenger vehicle through end-to-end CAE-Simulation using Transfer Path Analysis (TPA) approach2026-26-04311/16/2026
Refined NVH performance of a vehicle is a mark of premium quality. Achieving the desired NVH performance in different vehicle operating conditions is always a Herculean task and early stage “CAE design recommendations” play crucial role in overall vehicle design development. This becomes tougher when the program is very much cost, weight and timeline sensitive. This paper explores simulation approach for addressing a major noise issue for a vehicle running at a constant speed on a rough road. The first and the most critical step is to identify the exact root cause of the issue. Hence, we propose a detailed full vehicle level “contribution analysis (CA) + transfer path analysis (TPA)” methodology (everything done through the simulation) and then go for the design recommendations to improve the performance. We used road excitation power spectral density (PSD) as the input at all the four wheels (spindle locations) calculated through MBD software. The first step i.e. contribution analysis
Mahajani, Mihir, Nascimento, Fabio, ADINARAYANA REDDY, KODIDELA, Matyal, Mahantesh, Tenagi, Irappa, Sardar, Chenna
Black Box Approximation of EMI/EMC Filter Parasitics2026-26-03681/16/2026
Selecting the right EMI/EMC filter is a major challenge when system noise levels exceed compliance or pre-compliance limits. Inline PCB filters are designed to mitigate noise in standalone conditions, but their behavior changes when integrated into a larger system due to unknown parasitics. These parasitics can disrupt electromagnetic compatibility (EMC), leading to non-compliance. To address this, engineers often use off-the-shelf EMI filters, but determining their real-world effectiveness remains complex. Even with simulation-based methods, accurately predicting insertion loss and attenuation is difficult due to limitations in conventional modeling approaches. Traditional SPICE-based simulations rely on static models defined at specific frequency points, with interpolated values for intermediate frequencies. This interpolation introduces inaccuracies, affecting the precision of simulated results. To overcome these limitations, we propose a methodology that reconstructs a realistic
Pandey, Devbrat, Unterreiner, Michael, Mishra, Arvind, singh, Ankur
Failure Investigation and Geometric Optimization of Torsional Vibration Damper for Enhanced Durability and Noise Reduction in Automotive Drivetrain Systems2026-26-03501/16/2026
Internal Combustion engines exhibit multi-order vibrations caused by the inertial forces of reciprocating masses. These vibrations induce drivetrain resonance, negatively impacting occupant comfort and the durability of drivetrain components. Torsional vibrations, a critical subset of these oscillations, demand efficient damping mechanisms. Torsional Vibration Dampers are instrumental in minimizing such vibrations by tuning mass and frequency characteristics to prevent resonance. By splitting resonant frequencies into avoidable zones within the engine's operational range, TVD enhance vehicle performance and refinement by dampening the vibrations. Structurally, TVD comprise an inertia ring integrated with a damping medium, such as vulcanized rubber, which attenuates torsional oscillations by permitting controlled oscillation of the inertia ring. This study focuses on the failure investigation and the geometric optimization of oscillating masses of TVD for performance and durability
WANI, SUJIT ASHOK, S, Manickaraja, Kanagaraj, Pothiraj, Senthil Raja, T, Vellandi, Vikraman, Patil, Dilip
Assessment and Auralization of Cabin Noise from AVAS Operation in an Electric Vehicle Using a Hybrid BEM–SEA Methodology2026-26-03571/16/2026
In electric and hybrid vehicles, sound package optimization can follow a classical, proven, and structured approach for real-world loads, while also considering new transmission paths that might differ from those in traditional internal combustion engine vehicles. However, AVAS-induced interior noise is sometimes underestimated and therefore not taken into account during the optimization process. Nevertheless, especially at very low speeds, the presence of the AVAS can be perceived as an unwanted noise inside the vehicle, potentially compromising interior comfort. In this study, a hybrid boundary element–statistical energy analysis (BEM – SEA) approach is applied to an SEA dual-motor electric vehicle demonstrator model equipped with a baseline, standard sound package to assess AVAS-induced interior noise. A standard AVAS actuator is modeled, and a BEM model is used to compute the sound pressure levels on the exterior subsystems of the vehicle. These results are then transferred to the
Fiedler, Robert, Calloni, Massimiliano, Martin, Simon
EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION2026-26-03221/16/2026
Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine
JOSHI, ATUL KAMALAKARRAO, Subramanian, MANOJ
Evaluation of Vibration Reduction Techniques in Agricultural Tractors: A Design of Experiments Approach2026-26-03441/16/2026
Operator comfort is among the most crucial features of agricultural tractors. Tractor operators work long hours and are subjected to vibrations and mechanical shocks, which are potentially harmful to their health. When selecting a tractor for agricultural use, one of the main factors to consider is tactile vibrations. The mandate for this project includes an investigation of tractor vibration control issues. For identifying the source of the issue, study of the controlling system is crucial. The objective of the study was to evaluate the vibrations transmitted through the tractor and to reduce vibrations on specific tactile locations through the design of experiments (DOE) method. In this paper, testing is performed on the specified tactile locations; to reduce resonance-induced vibrations, a range of approaches are being explored, including lowering the natural frequency away from the second-order engine frequency and improving the damping coefficient to lower the vibration amplitude
Baviskar, Shreyas, dhobale, Vishwajeet, Bhangare, Amit, Kunde, Sagar, Wagh, Sachin
Resolution of Automotive Air Compressor Noise in Low Powered ICE vehicle2026-26-03141/16/2026
Passenger compartment's interior noise and thermal performance are one of the essential criteria for the driving comfort of vehicles. This paper explains that how the AC compressor noise is optimized in specific to low powered 1 L - ICE engine and 120 cc IVDC compressor combination. This combination is quite challenging due to high operational load & higher operating pressure. For better in-cabin cooling efficiency, compressor operating efficiency to be improved which in turn leads to higher displacement of the compressor. Higher displacement will lead to higher internal forces which leads to more structure borne induced noise in-side the cabin. For this specific combination, the compressor operating pressure reached to 25 bar at most of the driving condition. During dynamic driving condition, compressor metallic tonal noise was reported in one of the A segment vehicle developments. It was reported as very annoying to inside passenger. Transfer Path Analysis, Compressor fixation point
John Britto, Vijay Antony, Maluganahalli-Dharmappa Madhusoodan Sr, 1Lt Madhusoodan, Natarajasundaram, Balasubramanian
Combustion noise quality improvement in a common rail Diesel Engine at Low idle for Agriculture Tractor2026-26-03291/16/2026
Vehicle level NVH performance plays major role in customer comfort criteria. Tractor low idle rpm Sound Quality can be one of the parameter which influences customer purchasing decision based on comfort criteria. Modern diesel engines with stringent emission norms together with fuel economy requirements pose challenges to noise control. Common rail engine technology has advantage of precise fuel delivery and combustion control which needs optimization to achieve the conflicting requirements of noise, emission and fuel efficiency. Engine noise at low idle condition is dominated by combustion noise which depends on rate of pressure rise inside the cylinder during combustion. The important parameters which influence cylinder pressure rise are fuel injection timing, pilot injection quantity and its separation, rail pressure and EGR valve position. The study is carried out to understand which combustion parameter is most influencing to achieve better sound quality of engine. Taguchi design
p, Priyadarshan, Chavan, Amit, A, Kannanswamy, Patil, Sandeep, Chaudhari, Vishal V
Experimental Frequency-Based Substructuring for Full-Vehicle NVH Characterization in Electric Vehicles2026-26-03091/16/2026
Electric vehicles introduce new NVH challenges due to high-frequency excitations from e-motors and associated electronics. These excitations, often in the kilohertz range, are primarily transmitted as structure-borne noise and require advanced experimental methods for accurate characterization and mitigation. Traditional simulation approaches are insufficient to capture the true dynamic behavior of complex components under operational boundary conditions. This study presents a fully experimental Frequency-Based Substructuring (FBS) methodology applied to a complete electric vehicle. Frequency Response Functions (FRFs) of individual subsystems—such as the e-motor, mounting system, inverter housing, and body connection points—are measured and transformed using Virtual Point Transformation to obtain consistent six-degree-of-freedom representations. These Virtual Point models are assembled into a full-vehicle system to investigate the structure-borne transfer paths to the vehicle interior
Kohlhofer, Daniel, Pingle, Pawan Sharad, de Klerk PhD, Dennis
Adaptive Control Algorithms for Active Mounts on Diesel Powertrains in Passenger Cars2026-26-03241/16/2026
Diesel powertrains are inherently characterized by high vibration levels and low-frequency excitations, which are extremely demanding for passenger comfort and vehicle refinement. Conventional passive engine mounts often fall short in mitigating such vibrations effectively across a wide range of operating conditions. Passive mounts are inadequate for effectively isolating vibrations in powerful, lightweight vehicles or those without a balancer shaft 3-cylinder engine ordiesel engines. Consequently, this has prompted the consideration of active engine mounts as an alternative solution for solving NVH (Noise, Vibration, Harshness)-related issues. This paper explores the application of adaptive control algorithms in active engine mount systems for diesel powertrains in passenger vehicles. Through the integration of real-time feedback loops with smart control strategies the system adaptively controls mount stiffness and damping to minimize engine-induced vibrations. The study presents
Hazra, Sandip, Khan, Arkadip Amitava, more, Vishwas
Tractor Cabin Structure Borne Noise Reduction in the Virtual Environment2026-26-01011/16/2026
In recent days, cabin variants in the tractor are preferred by the farmers for the Coziness and longer field hour operation with less fatigue. Noise perceived by customer is the most important factor taken into account during the design stage, as it’s directly linked with operator’s comfort. Observed noise levels has to be within the defined limits as per national/international standards Overall cabin noise levels is contributed by the structure borne noise below 630 Hz. Structure borne noise is the noise typically radiated by the door, roof, windshield, floor, fender and structure assembly due to the engine excitation through the transmission housings and backstories. This paper depicts the process of tractor cabin structure borne noise prediction in the virtual environment. Firstly, Engine bearing loads and axle bearings has been extracted in the virtual stage from the vehicle level driveline model using commercially available MBD software. The finite element (FE) model of the cabin
gunasekaran, pandiyanayagam, K, Somasundaram, Chavan, Amit
Optimized Panel Design for Reducing Seal Squeak and Chucking in Door & Body Seals2026-26-03411/16/2026
Quieter cabins in an automobile are the new era, they provide customers with pleasurable driving experience. Squeak and Rattle are spoil sport for any OEM that aim to improvise customer driving experience. Their nonlinear nature makes it difficult to formulate design frontloading methods. The issue of seals rubbing against the body & door interface is a clear sign of seal squeak & seal chucking. Seals are applied with anti-friction coatings to avoid stick slip phenomena between EPDM and painted panel. Primary root cause for seal squeak is coating erosion. The challenge lies in determining whether the body or the closure side contributes to the seal issue. This paper presents a distinctive approach for identifying the seal squeaking noise and enriches on the new modelling methods for seal interaction with door and body interfaces using FE software. The proposed method was able to highlight the locations along the door-body interface for squeak noise. The approach for reducing the
H, RAVISHANKAR, C M, MITHUN, MICHAEL STEPHAN, NAVIN ESTAC RAJA, Mohammed, Riyazuddin
Contradictions of Automotive NVH with other Vehicle Performance and TRIZ tools for Innovative problem solving2026-26-03471/16/2026
For safety towards Automotive engineering often faces design contradictions, particularly in Noise, Vibration, and Harshness (NVH) optimization. Traditional approaches rely on trade-offs, but TRIZ (Theory of Inventive Problem Solving) offers a structured methodology to resolve contradictions innovatively. This paper explores in depth the TRIZ-based solutions for 2 key NVH challenges: (1) exhaust systems requiring noise reduction while maintaining low engine back-pressure, (2) engine mounts requiring both softness for vibration isolation and hardness for durability& vehicle stability. By applying principles such as segmentation, dynamization, parameter change, cheap short living objects or mechanics substitution, the novel solutions are proposed to achieve superior performance without traditional compromises. Tuneable valves in the path of the exhaust gas flow and the power-train mounting focused on its Torque Roll Axis were shown to exemplify the TRIZ problem solving effectiveness
A, Milind Ambardekar
Measurement of Acoustic Sensitivity of Automotive Drum Brake to Multiple Faults2026-26-05551/16/2026
Multiple faults can occur over time in drum brakes, which are commonly used on the rear of heavy vehicles and two-wheelers, compromising passenger safety and ergonomics. Given the recent success of artificial intelligence in fault diagnosis, it can be applied effectively to automotive brakes during operation when combined with advanced measurement techniques. However, monitoring the brake health during operation is challenging due to the rotational motion of components and space constraints for sensors. Consequently, this study investigates the use of measured radiated noise from drum brakes (instead of vibrations) to detect faults. A test bench mimicking typical on-road braking dynamics has been developed to operate in a controlled environment with pre-determined fault levels. This setup measures acoustic signals during transient brake events. Acoustic responses from several experiments that imitate three common brake fault conditions are measured. The acoustic sensitivity to each
Shripad, Kumar Milind Rewanand, Yella, Akash, Sundar, Sriram
An Engineering Perspective on Cradle and Saddle Mount Configurations2026-26-03131/16/2026
The evolution of electric vehicles (EVs) demands optimized powertrain mounting systems to achieve superior Noise, Vibration, and Harshness (NVH) performance. This study presents a comparative evaluation of cradle-type and saddle-type mounting systems in EV applications. Experimental modal analysis and vehicle-level vibration testing were conducted to assess structure-borne and airborne noise transmission across operating conditions. Key factors such as mount stiffness, isolation efficiency, and dynamic load distribution were analyzed. Cradle systems exhibited better low- to mid-frequency isolation, whereas saddle systems offered advantages in packaging flexibility, high-frequency noise control, and reduced load distribution on supporting structures. These findings provide valuable guidance for selecting optimal mount strategies to enhance occupant comfort and acoustic quality in future EV designs. Recommendations for mount system improvements considering evolving EV architectures are
Hazra, Sandip, more, Vishwas, Naik, Sarang Pramod
Prediction of Trimmed BIW Noise transfer function based on BIW response using Machine Learning2026-26-06401/16/2026
This research focuses on the prediction of the Noise Transfer Function (NTF) in a trimmed Body-in-White (BIW) structure by leveraging machine learning technique considering BIW-level NTF, dynamic stiffness at engine mount attachment points, and Vibration Transfer Function (VTF). The study employs an iterative methodology, adjusting the thickness of various BIW panels to analyse their impact on noise transfer characteristics. Frequency response functions are generated at the BIW attachment points to assess the effectiveness of these modifications. By systematically increasing and decreasing panel thicknesses, and stiffness at the attachment point and trimmed BIW level responses the study aims to optimize the acoustic performance of the BIW structure. The findings provide critical insights into the relationship between structural modifications and noise transfer, offering valuable guidance for automotive design and engineering during early design stage to reduce the development time.
Kulkarni, Prasad Ramesh, Bijwe, Vilas, Kulkarni, Shirish, Sahu, Dilip, Inamdar, Pushpak
An analysis of material damping characteristics: A comparison of Oberst Bar Method and Center Impedance Method and their relationship to Component Level.2026-26-03171/16/2026
Damping materials exhibit advantageous mechanical and acoustic characteristics that enhance the structural integrity of systems. These materials find extensive applications across various industries, including automotive, aerospace, and building acoustics, and are widely employed in the development of soundproofing materials. The damping characteristics of materials primarily pertain to the dissipation of vibrational energy, the reduction of oscillations, and the controlling and subsequent attenuation of vibration-induced noise emanating from structures. To improve both structural integrity and acoustic performance, it is crucial to accurately assess the damping properties of these materials. The Oberst bar test method is a standard method used in the automotive, railway and building industry for initial optimization of damping material However, questions have arisen about the degree to which the outcomes of the Oberst test truly reflect real-world applications. Numerous experimental
Kamble, Prashant Prakash, Joshi, Manasi, Jain, Sachinkumar
Strategic Design of Intake Systems for Crafting a Sporty Acoustic Signature in Passenger Vehicles2026-26-03281/16/2026
In pursuit of a distinct sporty interior sound character, the present study explores an innovative strategy for designing intake systems in passenger vehicles. While most existing literature primarily emphasizes exhaust system tuning for enhancing vehicle sound quality, the current work shifts the focus toward the intake system’s critical role in shaping the perceived acoustic signature within the vehicle cabin. In this research work, target cascading and settings were derived through a combination of benchmark and structured subjective evaluation study and aligning with literature review. Quantitative targets for intake orifice noise was defined to achieve the desired sporty character inside cabin. Intake orifice targets are engineered based on signature and sound quality parameter required at cabin. Systems are designed by using advanced CAE techniques, Specific identified acoustic orders were enhanced in the intake system to reinforce the required signature in acceleration as well
Sadekar, Umesh Audumbar, Titave, Uttam, Patil, Jitendra
Simulation based optimization of the NVH characteristics in modern high speed engine during development phase2026-26-03261/16/2026
Engine noise mitigation is paramount in powertrain development for enhanced performance and occupant comfort. Identifying NVH problems at the prototype stage leads to costly and time-consuming redesigns and modifications, potentially delaying the product launch. NVH simulations facilitate identification of noise and vibration sources, informing design modifications prior to physical prototyping. Early detection and resolution of NVH problems through simulation can significantly shorten the overall development cycle and multiple physical prototypes and costly redesigns. During NVH simulations, predicting and optimizing valvetrain and timing drive noise necessitates transfer of bearing, valve spring, and contact forces to NVH simulation models. Traditional simulations, involved continuous force data export and NVH model evaluation for each design variant, pose efficiency challenges. In this paper, an approach for preliminary assessment of dB level reductions across design iterations is
Rai, Ankur, Deshpande, Ajay Mahadeo, YADAV, RAKESH
Development of a GUI-Based Pitch Sequence Optimization Tool for Tyre Noise Reduction2026-26-03301/16/2026
Minimizing tyre noise is essential for enhancing ride comfort, especially in electric vehicles where the absence of engine noise makes tyre-generated sound more prominent. This work presents the development of a GUI-based pitch sequence optimization tool to support tyre design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. This tool plays a pivotal role in the tire development process, serving as one of the key evaluation criteria for tread pattern approval before mould fabrication. By enabling engineers to generate balanced, low-noise pitch sequences that align with both acoustic targets and engineering constraints, the tool facilitates faster design iterations and smooth integration with downstream processes. Its successful
Sampathraghavan, Lakshmi, Ramarathnam, Krishna Kumar, Mantripragada PhD, Krishna Teja, Ramachandran, Neeraj
Sound quality refinement and vibration reduction during Horn Application in Electric Vehicles2026-26-03381/16/2026
This paper focuses on the cabin sound quality refinement and the tactile vibration reduction during horn application in the electric vehicle. Horn cracking sound is perceived in the cabin while pressing the horn. Higher vibrations are also perceived in accelerator pedal during the particular event. Sound diagnosis is carried out to identify the frequencies contributing to cracking noise. Transfer path analysis is conducted to identify the nature of noise and the predominant path through which forces transfer. Based on finding from TPA, various recommendations are evaluated which reduced the noise to a certain extent. Operational Deflection Shape(ODS) is conducted on the horn, horn mounting bracket and on the body to identify the component having higher deflection at the problematic frequencies . Based on the outcome of ODS, recommendations like dynamic stiffness improvement on the horn bracket and the body is assessed and the effect of each outcome is discussed. With all the
S, Nataraja Moorthy
Developing Advanced CAE Model for Door Glass Regulator Operating Noise Reduction through TEST/CAE Correlation2026-26-03111/16/2026
The importance of performance improvement and weight optimization using CAE in the early design stages of vehicle development has been continuously increasing over the past two decades. And, the accuracy of CAE models plays key role, more efforts are required to improve it. Representation of exact physical model in CAE is still a big challenge for achieving an accurate TEST vs CAE correlation. In this research, the procedure and application of door system model correlation were described to reduce the glass regulator operating noise. The function of a regulator in door system is to open and close the glass. The regulator under improper design creates unwanted noise and discomfort to the passenger. In current door CAE Model, we are unable to identify this real time problem. Therefore, this paper discusses how to correlate door system model according to the assembly stage based on modal correlation and it helped in calculating accurate glass regulator operating noise. As a result, the
PANUGANTI, NARESH KUMAR, Choi, Seungchan
Optimization of Electric Drive Unit Mounting for Vibration Isolation in EV Powertrains Using Multibody Dynamics2026-26-00801/16/2026
With growing significance of electric vehicles (EVs), their powertrains—while naturally quieter than internal combustion engine (ICE) powertrains—pose new NVH (Noise, Vibration, Harshness) challenges. These are triggered mainly from high-frequency disturbances caused by electric motors and gear interactions. Isolation of such excitations is essential for securing cabin refinement and customer expectations for acoustic comfort. This paper offers a simulation-based approach to optimal placement of the electric drive unit (EDU), which houses the electric motor and gearbox, with the objective of reducing vibration transfer to the chassis of the vehicle. The methodology explores the effect of spatial mount repositioning under actual dynamic load conditions through multibody dynamics (MBD) modeling and integrated optimizer using advanced multibody dynamics simulation software – Virtual Dynamics. The suggested workflow helps in effective investigation of mount positioning within packaging
Mane, Prashant, Shah, Swapnil, Back PhD, Arthur, Pinjari, Abrar, Emran, Ashraf, Mane PhD, Shrikala
Optimizing Tire NVH Performance in Electric Vehicles: A Comprehensive Approach Using Benchmarking, Simulation, and Validation2026-26-06051/16/2026
The electrification of mobility is becoming increasingly vital in meeting global zero carbon footprint targets, with nations setting ambitious goals to achieve by 2030. As part of this transformation, the development of Electric SUVs (E-SUVs) capable of navigating diverse terrains and road conditions presents a significant challenge, often extending vehicle development timelines. To address these demands, many Original Equipment Manufacturers (OEMs) are adopting a ‘Born-Electric’ platform approach, specifically tailored to the unique requirements of electric vehicles. However, this approach introduces several challenges, particularly in maintaining the Noise, Vibration, and Harshness (NVH) levels expected by customers. The elimination of the Internal Combustion Engine (ICE) powertrain has significantly shifted the NVH dynamics of E-SUVs, with tire road rolling noise becoming a dominant factor influencing in-cabin noise perception, Tire-induced noise and vibrations emerge as primary
Singh, Ram Krishnan, Deivasigamani Purushothaman, Balakrishnan, Paua, Ketan, ahire, Manoj, Adiga, Ganesh N
Noise Reduction of Construction Equipment Vehicle Through Structure-borne and air-borne Noise Reduction Strategy2026-26-03181/16/2026
One can witness the constant development and redevelopment of cities throughout the world. Construction equipment vehicles (CEVs) are commonly used on the construction site. However, the noise pollution from construction sites due to the use of CEV has become a major problem for many cities. The construction equipment employed is one of the main causes of these elevated noise levels. The construction workers face a potential risk to their auditory health and well-being due to the noise levels they are exposed to. Different countries have imposed exterior and operator’s ear noise limits for construction equipment vehicles, enabling them to control noise pollution. In this study, three vehicles were selected and checked for NVH performance and found that the operator ear noise level of the identified vehicle is 6 dB(A) higher than the benchmark vehicle level in dynamic conditions, when tested as per ISO 6396. Similarly, there was another vehicle having exterior noise 2 dB(A) higher than
Shinde, Gaurav, Jawale, Pradeep, Jain, Sachinkumar, Harishchandra Walke, Nagesh
Investigation and Reduction of Road Noise due to transient road inputs in Electric Vehicle2026-26-03581/16/2026
Higher road noise is perceived in the cabin when the test vehicle encounters road irregularities like bump or pothole in the public roads. The sudden transfer of transient road inputs inside the body caused objectionable cabin noise. Measurements are conducted on the test track at different road surfaces to identify the patch where the objective data well correlated with the noise measured at the public road. Wavelet analysis is carried out to identify the frequency zones since the events are transient in nature. Transfer Path Analysis (TPA) is conducted in both time domain and frequency domain to identify the nature of the noise and the limitation in each of the methodologies are explained. The dominant path through which the transient road forces are transferring inside the body are also identified. Based on the outcome of TPA, various countermeasures like reduction of dynamic stiffness of suspension and cradle bushes , structural modifications on the path are proposed to reduce the
S, Nataraja Moorthy
Investigation of Low Frequency Interior Noise due to Tyre-Road Interaction2026-26-03511/16/2026
Unlike internal combustion engine (IC Engine) vehicles, the rapidly growing electric vehicle (EV) market demands tyres with superior yet often conflicting performance characteristics. The increased weight of EVs, due to their heavy batteries, necessitates robust tyres with reinforcement and higher inflation pressure. Conversely, increased wear due to higher initial torque and the need for lower rolling resistance to extend range, combined with the requirement for better grip for improved handling, call for advanced compound and tread pattern designs. EV tyres need to be stiffer, lighter, and less dampened, making it very hard to reduce low-frequency (20-200 Hz) interior noise that was previously hidden by engine noise. This study investigates the low-frequency (20-200 Hz) structural-borne interior noise performance of EV tyres using both experimental and simulation tools. By wisely tuning the tyre's stiffness, mass, and damping properties, the necessary noise targets can be met. These
Subbian, Jaiganesh, M, Saravanan
Use of Statistical Energy Analysis to predict Articulation Index (AI) in a vehicle interior for real- world operating scenarios.2026-26-04301/16/2026
Vehicle interior noise is a crucial assessment criterion for automotive NVH. It has a significant effect on customer opinions about the quality of a vehicle. Articulation Index (AI) is one of the key sound metrics used to describe speech intelligibility and quantifies the middle and high frequency spectra associated to the internal noise of vehicle. In reality, Vehicle operating under dynamic condition experiences various air-borne noise sources such as tire rolling noise, powertrain noise, intake-exhaust noise & wind noise along with structure borne excitations such as powertrain vibrations, suspension vibrations. It is very challenging to predict cumulative effect of all these excitations to interior noise level and Articulation Index (AI) of vehicle over complete frequency range. The statistical energy analysis (SEA) is a well-known methodology being used to simulate & predict mid & high frequency noise. Objective of this paper is to present the process of development of a SEA
Doijad, Vishwajit Padmakar, Billade, Dayanand, Apte Sr., Amol Arun, Shewale, Amol, Kothapalli, Brahmananda Reddy
Analysis of door seal compression and its influence on NVH performance in heavy-duty vehicle2026-26-03391/16/2026
Seals in a truck cabin is one of the major contributors for cabin noise in terms of structure borne as well as air borne noise transfer path. This study emphasizes on the effect of door seal compression prediction and its impact on structure borne NVH in trucks. Vibrations are regarded as quality criteria in the perception of customers. It is necessary to ascertain the contribution of seal stiffness on compression of the seal under closed condition of the door rather than uncompressed conditions. The dynamic stiffness of door seal is calculated by non-linear analysis. The simulations models are constructed using the Mooney - Rivlin theory for both 2D and 3D seals. This encompasses contemplating the relevant seal mounted boundary condition on the body and the door of the vehicle. The stiffness after compression of seal is extracted from this non-linear analysis which is further used to obtain the vibration modes for the doors in the truck cabin. Subsequently, the compressed seal
L, Kavya, Ramanathan, Vijay
Low idle boom noise reduction on Light Weight Agricultural Cabin Tractor2026-26-01001/16/2026
In Last two decades, Farm customer expectation on Cabin comfort has been increased multifold. To provide the best-in-class customer experience in terms of comfort without adding cost and weight is bigger challenge for all NVH Engineers. It is evident from literature survey that cabin tractors with better comfort is well accepted by customers in US and European Market. Apart from engine excitation, customer has become more sensitive to customer-actuated-accessory noises due to overall reduction in cabin noise in last 2 decades. This paper presents the study conducted on HVAC blower noise in 30HP cabin tractor Tactile vibrations and Cabin Noise is not acceptable when AC is switched on due to low frequency modulating nature in frequency range of ~65Hz and 130Hz. The investigation is carried out systematically considering each component of Source-Path-Receiver model. HVAC blower unit as source is diagnosed in detail to understand root cause. Strong dominance of first order of blower been
K, Somasundaram, Chavan, Amit
Experimental Study to Investigate and Control Image Blurriness due to IRVM Vibration2026-26-03211/16/2026
Vibration is one of the prominent factors that determine the quality & comfort level of a vehicle. Moreover, if vibration occurs in areas that are almost entirely within customer touchpoints (during either city or highway driving conditions), it could become a critical factor behind the deterioration of brand image within the market. The interior rear-view mirror (IRVM) is one of the important components inside passenger cabin, providing drivers with a clear view of the rear traffic. However, vibrations induced by engine operation, road irregularities, and aerodynamic forces can cause the IRVM to oscillate, leading to image blurriness and compromised visibility and safety. This paper investigates the underlying causes of IRVM vibrations and their impact on image clarity. Through a combination of experimental analysis and computational modelling, we identify key factors contributing to mirror instability. The findings indicate the specific frequencies of vibration, particularly those
Khan, Aamir Naved, Saraswat, Vivek, Jha, Kartik, SINGH, HEMENDRA, Seenivasan, Gokulram, Khan, Nafees
NVH Refinement on the Agriculture Tractor using Coupled Test and Simulation Approach2026-26-03161/16/2026
The Indian farmers choice of agriculture tractor brand is driven by the ease of operation and fuel efficiency. However, the customer preference for operator comfort is driving many tractor OEMs for improvement in noise and vibration at the operator location. Also, the compliance to CMVR regulation for noise at operator ear location and vibration at driver touch point location are mandatory for all the tractors in India. NVH refinement development of the tractor plays a critical role in achieving the regulated noise level and improved tactile vibration In presented work, Noise Source Identification (NSI) is carried out to identify and rank airborne and structure borne noise sources at tractor level through elimination method followed by engine level testing in hemi anechoic chamber to identify the major noise radiating components by using noise and vibration measurement, sound intensity mapping tools. The outcome of NSI has revealed silencer, timing gear cover and oil sump to be highest
Gaikwad, Atul Annasaheb, Bankar, Harshal, Yadav, Prasad S, Harishchandra Walke, Nagesh
Structural and Micro-Geometry Optimization of an Electric drive unit for Whine Noise Reduction2026-26-03151/16/2026
The noise generated by pure electric vehicles (EVs) has become a significant area of research, particularly due to the increasing adoption of electrified propulsion systems aimed at meeting OEM fleet CO₂ reduction targets. Unlike internal combustion engines, which mask many drivetrain noises, EVs expose new challenges due to the quieter operation of electric motors. In this context, the transmission system and gear structures have emerged as primary contributors to noise, vibration, and harshness (NVH) in EVs. The present study provides an NVH study that focuses on the gear whine noise issue that is seen at the vehicle level and cascades to the powertrain level. Comprehensive root cause identification, focusing on the transmission system's structural and dynamic behavior. The research emphasizes modifications to both the gearbox housing and gear structures to reduce noise level, and model validation was all part of the study, which was accompanied by physical test results. Using MBS
Baviskar, Shreyas, Kamble, Pranit, Ghale, Guruprasad, Bendre, Parag, Prabhakar, Shantanu, Kunde, Sagar, Thakur, Sunil, Wagh, Sachin
Assessing Millable Polyurethane in Powertrain Mounting Applications: A Comparative Study with Natural Rubber2026-26-02891/16/2026
In the automotive industry, the performance and longevity of elastomer components are critical to both vehicle durability and driver comfort. Powertrain mountings, play a crucial role in isolating vibrations and reducing noise. Traditionally, natural rubber (NR) has been the material of choice for these applications due to its excellent vibration isolation properties, flexibility, and cost-effectiveness. However, with evolving performance demands, there is growing interest in enhancing the durability and noise, vibration, and harshness (NVH) characteristics of powertrain mountings, along with improving their resistance to environmental stressors such as heat, oil, and wear. Unlike NR, which tends to degrade more quickly under such conditions, millable polyurethane (MPU) offers superior resistance, making it a promising candidate for extending the service life of these critical components. The objective of this study is to determine whether millable polyurethane (MPU) can serve as a
Murugesan, Annarajan, Pawar, Rohit
Comprehensive evaluation and development of a single cylinder engine vehicle for refinement of NVH characteristics2026-26-03081/16/2026
The scale of worldwide population presents its own set of difficulties, especially in densely populated cities. Almost every individual has some form of personal transport, which leads to congestion and limited parking space. Automotive manufacturers are scaling down the size of vehicles to resolve these issues to some extent. This paper is based on the NVH development of a single-cylinder diesel engine vehicle. It provides an insight into the comprehensive vehicle level NVH refinement approaches adopted. The NVH characteristics of the benchmark two-cylinder diesel and baseline vehicle were measured and analyzed for target setting. The performance of each subsystem, such as engine mounting, vehicle structure, intake and exhaust, was evaluated, and gap analysis was performed against set targets. It was found that the engine mounting system and vehicle structure were inefficient in isolating the excitation forces. The design and location of the mounting system was evaluated using CAE and
Ghale, Guruprasad Chandrashekhar, Baviskar, Shreyas, Bendre, Parag, Kamble, Pranit, Bhangare, Amit, THAKUR, SUNIL, Kunde, Sagar, Wagh, Sachin
New generation Natural Rubber-Based Bump Stopper with Improved NVH Characteristics2026-26-02921/16/2026
In automotive suspension systems, components like bump stoppers and jounce bumpers play critical roles in controlling suspension travel and enhancing ride comfort. Material selection for these components is driven by functional demands and performance criteria. Traditionally, Natural rubber (NR) has traditionally been favoured for bump stopper applications due to its excellent vibration absorption, tear resistance, cost-effectiveness, and biodegradability. However, in more demanding environments, it has been largely replaced by microcellular polyurethane (PU) elastomers, which offer superior durability, environmental resistance, and enhanced noise, vibration, and harshness (NVH) performance. PU's high compressibility, low lateral expansion, and low compression set make it the material of choice across automotive, aerospace, and industrial sectors. Other materials like thermoplastic elastomers (TPE/TPU) and EPDM rubber are also used, offering advantages such as recyclability, ease of
Murugesan, Annarajan, Perumal, Mathavan
JAX9900JAX9900_202512 (Current)12/4/2025
JAX9900
Active Safety Systems Standards Committee
Measurement of Exterior Noise Produced by Aircraft Auxiliary Power Units (APUs) and Associated Aircraft Systems During Ground OperationARP1307C (Current)11/26/2025
Test procedures are described for measuring noise at specific receiver locations (passenger and cargo doors, and servicing positions) and for conducting general noise surveys around aircraft. Procedures are also described for measuring noise level and directivity at noise source locations to facilitate the understanding and interpretation of the data. Requirements are identified with respect to instrumentation; acoustic and atmospheric environment; data acquisition, reduction and presentation, and such other information as is needed for reporting the results. This document makes no provision for predicting APU or component noise from basic engine characteristics or design parameters, nor for measuring noise of more than one aircraft operating at the same time. No attempt is made to suggest acceptable levels of noise or suitable subjective criteria for judging acceptability. ICAO Annex 16 Volume I Attachment C provides guidance on recommended maximum noise levels.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Verifying large alternate product code for an Surface Vehicle RP document - JRP001JA/NEW/RP000000000000000000000001_202511 (Current)11/24/2025
Verifying large alternate product code for an Surface Vehicle RP document - JRP001
Active Safety Systems Standards Committee
Verifying large alternate product code for an JA GV document - JA1124XXJA1224XX/NEW/00000000000000000001_202511 (Current)11/24/2025
Verifying large alternate product code for an JA GV document - JA1124XX
Active Safety Systems Standards Committee
Shoreline Sound Level Measurement Procedure for Recreational MotorboatsJ1970_202511 (Current)11/21/2025
This SAE Recommended Practice establishes the procedure for measuring the sound level of recreational motorboats in the vicinity of a shore bordering any recreational boating area during which time a boat is operating under conditions other than stationary mode operation. It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Marine Technical Steering Committee
Gearbox Casing Crack Detection based on Vibration Signals in Frequency and Time DomainF-0081-2025-00285/20/2025
Gearbox casing cracks in helicopters would be critical impacting the aircraft's reliability and operation safety directly. The Defense Science and Technology Group (DSTG) HUMS2025 gearbox casing failure data set was the unexpected result of a test stand operation. The gearbox undergoes high cycle (> 400 acquisitions) under high torque (100% and 125% nominal torque) conditions. We hypothesized that the any cracking would be due to the planet/ring gear interaction. A condition indicator (CI) would be sensitive to a crack feature and this would be sensitive to change in gearbox torque. This paper explores the development of both a cyclo-stationary based CI (frequency-domain) and a time synchronous average CI (time-domain). The trend shows that proposed methods can help to detect localized defects in gearbox casing at an early stage and trend as the crack propagates before catastrophic failure occurs.
Cho, Changik, Bechhoefer, Eric
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