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Viewing 1 to 30 of 7888
2017-10-02 ...
  • October 2-6, 2017 (8:00 a.m. - 8:00 p.m.) - Troy, Michigan
Training / Education Classroom Engineering Academies
This Engineering Academy covers a variety of vehicle noise control engineering principles and practices. Two specialty tracks are available: Vehicle Interior Noise and Powertrain Noise. While the Powertrain Noise track focuses on NVH issues generated by powertrain noise sources and the design strategies to minimize them, the Vehicle Interior Noise track focuses on the understanding and application of acoustical materials to optimize NVH in the passenger or operator compartment of a vehicle. Considerable attention is given to current measurement and instrumentation technologies and their effective use.
2017-10-02 ...
  • October 2-6, 2017 (8:00 a.m. - 8:00 p.m.) - Troy, Michigan
Training / Education Classroom Engineering Academies
This Engineering Academy covers a variety of vehicle noise control engineering principles and practices. Two specialty tracks are available: Vehicle Interior Noise and Powertrain Noise. While the Vehicle Interior Noise track focuses on the understanding and application of acoustical materials to optimize NVH in the passenger or operator compartment of a vehicle, the Powertrain Noise track focuses on NVH issues generated by powertrain noise sources and the design strategies to minimize them. Noise sources include engines, transmissions/transfer cases, accessories, exhaust, gears, axles, joints, and couplings.
2017-09-29 ...
  • September 29, 2017 (8:30 a.m. - 4:30 p.m.) - Orlando, Florida
Training / Education Classroom Seminars
Brake noise is one of the highest ranked complaints of car owners. Grunts, groans, squeaks, and squeals are common descriptions of the annoying problem which brake engineers spend many hours trying to resolve. Consumer expectations and the high cost of warranty repairs are pushing the optimization of brake NVH performance. This course will provide you with an overview of the various damping mechanisms and tools for analyzing and reducing brake noise. A significant component of this course is the inclusion of case studies which will demonstrate how brake noise squeal issues have been successfully resolved.
2017-08-15 ...
  • August 15-17, 2017 (2 Sessions) - Live Online
Training / Education Online Web Seminars
This web seminar provides an in-depth overview of diesel engine noise including combustion and mechanical noise sources. In addition, the instructor will discuss a system approach to automotive integration including combining sub-systems and components to achieve overall vehicle noise and vibration goals.
2017-08-01 ...
  • August 1-10, 2017 (4 Sessions) - Live Online
Training / Education Online Web Seminars
This four-session web seminar provides a detailed understanding of the source – path-receiver relationship for developing appropriate sound package treatments in vehicles, including automobiles, commercial vehicles, and other transportation devices. The course provides a detailed overview of absorption, attenuation (barrier), and damping materials and how to evaluate their performances on material, component, and vehicle level applications. A significant part of this course is the case studies that demonstrate how properly designed sound package materials successfully address vehicle noise issues.
2017-06-17
Journal Article
2017-01-9550
David Neihguk, M. L. Munjal, Arvind Ram, Abhinav Prasad
Abstract A production muffler of a 2.2 liter compression ignition engine is analyzed using plane wave (Transfer Matrix) method. The objective is to show the usefulness of plane wave models to analyze the acoustic performance (Transmission Loss, TL) of a compact hybrid muffler (made up of reactive and dissipative elements). The muffler consists of three chambers, two of which are acoustically short in the axial direction. The chambers are separated by an impervious baffle on the upstream side and a perforated plate on the downstream side. The first chamber is a Concentric Tube Resonator (CTR). The second chamber consists of an extended inlet and a flow reversal 180-degree curved outlet duct. The acoustic cavity in the third chamber is coupled with the second chamber through the acoustic impedances of the end plate and the perforated plate.
2017-06-15 ...
  • June 15-16, 2017 (8:30 a.m. - 4:30 p.m.) - Grand Rapids, Michigan
Training / Education Classroom Seminars
The sound package materials for vehicle noise control seminar provides a detail and thorough analysis of three different classes of acoustical materials – namely absorbers, barriers, and dampers, how they are different from each other, and acoustical properties that materials should possess for optimum vehicle noise control. The seminar addresses new advances in acoustical materials, primarily in absorption materials that impact the vehicle acoustics. The seminar covers ways to evaluate the acoustical performance of these materials using different test methods, including material, component, and vehicle level measurements.
2017-06-05
Technical Paper
2017-01-1867
Mustafa Tosun, Mehdi Yildiz, Aytekin Ozkan
Abstract Structure borne noises can be transmitted to interior cabin via physical connections by gearbox as well as other active components. Experimental Transfer Path Analysis (TPA) Methods are utilized to investigate main paths of vibrations which are eventually perceived as noise components inside the cabin. For identifying the structure and air borne noise transfer paths in a system, Matrix Inversion (MI), Mount Stiffness (MS), Operational Transfer Path Analysis (OTPA) and Operational Path Analysis with Exogenous Inputs (OPAX) Methods exist. In this study, contribution ranking of transmission paths from active system components through the physical connections into the interior cabin are investigated by MI and OPAX Methods and finally a comparison of them is presented based on the accuracy of obtained results. The modifications are applied on dominant transfer paths which are determined by the mentioned methods above, respectively.
2017-06-05
Technical Paper
2017-01-1752
Kapil Gupta, Arun Choudhary, Rakesh Bidre
Abstract At present, a Dual Mass Flywheel (DMF) system is widely known to provide benefits on driveline induced noise, vibration and drivability over a Single Mass Flywheel (SMF). A well-tuned DMF provides nice isolation of torsional vibrations generated in periodic combustion process of automobile IC engines. Similarly, a torsional vibration damper mounted on driveline component reduces the torsional excitation and results a lower torsional vibration at driveline components. Noise and vibration issues like boom noise and high vibrations at low engine RPM range drive are often resulted due to high engine firing order torsional excitation input to the driveline. More often, this becomes one of the most objectionable noise and vibration issues in vehicle and should be eliminated or reduced for better NVH performance. A 4 cylinder, 4 stroke small diesel engine equipped with SMF is found to have high engine firing order torsional excitation.
2017-06-05
Technical Paper
2017-01-1754
Kyoung-Jin Chang, Seonghyeon Kim, Dong Chul Park, So Youn Moon, Sunghwan Park, Myung Hwan Yun
Abstract This paper aims to establish a systematic process of developing a brand driving sound. Firstly, principal factors of a brand sound identity are extracted from factor analysis of many sample cars. As a result, brand sound positioning map is drawn using jury test data. Also, the multiple regression analysis of subjective and objective test results is carried. As a result, the principal factors are expressed by objective test data and brand sound positioning map can be easily updated from the measurement data. In addition, what should be improved for designing a target sound is reviewed. Secondly, various technologies of target sound design are discussed to involve the brand identity and vehicle’s character in driving sound. Also, an efficient tool to implement the target sound with an active sound design (ASD) system in a vehicle is introduced. This tool enables to efficiently design, tune and simulate a target sound for ASD system in a laboratory.
2017-06-05
Technical Paper
2017-01-1753
Jack Hall Riddle, Ya-Juan Bemman, Tom Frei, Sihui Wu, Ishang Padalkar
Abstract Demands for engines to operate at low-frequency firing order are increasing in the automotive market. This requirement is driven by consumer and regulatory demand for vehicles which are more efficient in the use of fuel. As a result, engine and transmission technologies have been developed which permit operation of engines with fewer cylinders at increasingly low RPM’s. The resulting low frequency exhaust noise is more difficult to attenuate than in vehicles in years past. At the same time, vehicles often have less packaging space for mufflers, when larger volume would otherwise be needed to attenuate at lower frequencies. A further challenge is the demand for increasingly refined performance sounds from the exhaust systems of premium cars despite the technical obstacles involved in even maintaining sound quality. Finally, legally permissible sound levels are decreasing in some markets. These market and regulatory demands require new solutions.
2017-06-05
Technical Paper
2017-01-1757
Matthew Maunder, Benjamin Munday
Abstract Excitement, image and emotion are key attributes for cars, particularly those with higher power ratings. Engine sound has traditionally acted as the car’s voice, conveying these attributes to the driver and passengers along with the brand image. Engine sound also underpins the dynamic driving experience by giving instant feedback about how a car is operating, enhancing the connection between driver and vehicle. For decades, the automotive industry has engineered engine sound to achieve these benefits, thereby defining the ‘language’ of car sound. Electric vehicles deliver strong and responsive performance but naturally lack the acoustic feedback that internal combustion engines provide. While this gives advantages in terms of comfort and environmental noise, the benefits of engine sound are lost. Carefully controlled acoustic feedback inside the car’s cabin brings tangible and valuable benefits both for the dynamic driving experience and to convey the brand image.
2017-06-05
Journal Article
2017-01-1758
Seung Min Lee, Dong Chul Park, Seonghyeon Kim, Sang Kwon Lee
Abstract Recently the interior sound is actively generated by the active sound design (ASD) device in a passenger car. Therefore, the objective evaluation method for the sound quality of actively designed sounds is required. In previous research, the sound quality of interior sound has been presented with powerful and pleasant for the existing passenger car. This paper presents a novel approach method for the objective evaluation of powerfulness and pleasantness of actively designed interior sound. The powerfulness has been evaluated based on the degreed of modulation and a quantity of low frequency booming of the sound in the paper. On the other hand, the pleasantness is evaluated based on the slope ratio of harmonic orders per octave in frequency domain. These evaluation methods are successfully applied to the objective evaluation of luxury passenger car.
2017-06-05
Journal Article
2017-01-1756
Seonghyeon Kim, Kyoung-Jin Chang, Dong Chul Park, Seung Min Lee, Sang Kwon Lee
Abstract This paper presents a systematic approach to interior engine sound design for enhancing sound character of car interior sound effectively. Nowadays an active noise control technology is widely used in vehicle industry. Particularly, an active sound design (ASD) technique using vehicle’s audio system for controlling interior sound due to powertrain has become a general method to improve sound quality or character. The ASD system using speakers has the advantage of creating various sounds relatively easy. In this study, the novel systematic approach is proposed to guide the efficient design of powerful and pleasant acceleration sound by order spectrum analysis. At first, primary attributes of powerful and pleasant sound were analyzed and sound concept was derived. Secondly, the optimal linearity and the level envelope of firing order were derived by subjective evaluation.
2017-06-05
Technical Paper
2017-01-1755
Frank C. Valeri, James T. Lagodzinski, Scott M. Reilly, John P. Miller
Abstract Hybrid powertrain vehicles inherently create discontinuous sounds during operation. The discontinuous noise created from the electrical motors during transition states are undesirable since they can create tones that do not correlate with the dynamics of the vehicle. The audible level of these motor whines and discontinuous tones can be reduced via common noise abatement techniques or reducing the amount of regeneration braking. One electronic solution which does not affect mass or fuel economy is Masking Sound Enhancement (MSE). MSE is an algorithm that uses the infotainment system to mask the naturally occurring discontinuous hybrid drive unit and driveline tones. MSE enables a variety of benefits, such as more aggressive regenerative braking strategies which yield higher levels of fuel economy and results in a more pleasing interior vehicle powertrain sound. This paper will discuss the techniques and signals used to implement MSE in a hybrid powertrain equipped vehicle.
2017-06-05
Technical Paper
2017-01-1763
Lisa Steinbach, Ercan Altinsoy, Robert Rosenkranz
Abstract In today's urban environment inhabitants are permanently exposed to elevated noise levels, which are dominated by traffic noise. The process of electrification of vehicles might change the traffic noise in city centers. The aim of this work was to determine the pedestrian reaction, the warning effect and the annoyance of more realistic traffic situations. For this purpose both combustion and electric vehicle noise situations and mixed scenarios of both concepts were generated. The differences in the perceived annoyance and warning effect were investigated with perception studies.
2017-06-05
Journal Article
2017-01-1762
Michael Roan, M. Lucas Neurauter, Douglas Moore, Dan Glaser
Abstract Hybrid and electric vehicles (HVs and EVs) have demonstrated low noise levels relative to their Internal Combustion Engine (ICE) counterparts, particularly at low speeds. As the number of HVs/EVs on the road increases, so does the need for data quantifying auditory detectability by pedestrians; in particular, those who are vision impaired. Manufacturers have started implementing additive noise solutions designed to increase vehicle detectability while in electric mode and/or when traveling below a certain speed. A detailed description of the real-time acoustic measurement system, the corresponding vehicular data, development of an immersive noise field, and experimental methods pertaining to a recent evaluation of candidate vehicles is provided herein. Listener testing was completed by 24 legally blind test subjects for four vehicle types: an EV and HV with different additive noise approaches, an EV with no additive noise, and a traditional ICE vehicle.
2017-06-05
Technical Paper
2017-01-1760
Weimin Thor, J. Stuart Bolton
Abstract Due the increasing concern with the acoustic environment within automotive vehicles, there is an interest in measuring the acoustical properties of automotive door seals. These systems play an important role in blocking external noise sources, such as aerodynamic noise and tire noise, from entering the passenger compartment. Thus, it is important to be able to conveniently measure their acoustic performance. Previous methods of measuring the ability of seals to block sound required the use of either a reverberation chamber, or a wind tunnel with a special purpose chamber attached to it. That is, these methods required the use of large and expensive facilities. A simpler and more economical desktop procedure is thus needed to allow easy and fast acoustic measurement of automotive door seals.
2017-06-05
Technical Paper
2017-01-1761
Daniel Fernandez Comesana, Graciano Carrillo Pousa, Emiel Tijs
Abstract The automotive industry is currently increasing the noise and vibration requirements of vehicle components. A detailed vibro-acoustic assessment of the supplied element is commonly enforced by most vehicle manufacturers. Traditional End-Of-Line (EOL) solutions often encounter difficulties adapting from controlled environments to industrial production lines due the presence of high levels of noise and vibrations generated by the surrounding machinery. In contrast, particle velocity measurements performed near a rigid radiating surface are less affected by background noise and they can potentially be used to address noise problems even in such conditions. The vector nature of particle velocity, an intrinsic dependency upon surface displacement and sensor directivity are the main advantages over conventional solutions. As a result, quantitative measurements describing the vibro-acoustic behavior of a device can be performed at the final stage of the manufacturing process.
2017-06-05
Technical Paper
2017-01-1766
Dirk von Werne, Stefano Orlando, Anneleen Van Gils, Thierry Olbrechts, Ivan Bosmans
Abstract A methodology to secure cabin noise and vibration targets is presented. Early in the design process, typically in the Joint Definition Phase, Targets are cascaded from system to component level to comply with the overall cabin noise target in various load cases. During the Detailed Design Phase, 3D simulation models are build up to further secure and refine the vibro-acoustic performance of the cabin noise related subsystems. Noise sources are estimated for the target setting based on layer analytical and empirical expressions from literature. This includes various types of engine noise - fan, jet, and propeller noise - as well as turbulent boundary layer noise. For other noise sources, ECS and various auxiliaries, targets are set such as to ensure the overall cabin noise level. To synthesize the cabin noise, these noise sources are combined with estimates of the noise transfer through panels and the cavity effect of the cabin.
2017-06-05
Journal Article
2017-01-1765
Albert Allen, Noah Schiller, Jerry Rouse
Abstract Corrugated-core sandwich structures with integrated acoustic resonator arrays have been of recent interest for launch vehicle noise control applications. Previous tests and analyses have demonstrated the ability of this concept to increase sound absorption and reduce sound transmission at low frequencies. However, commercial aircraft manufacturers often require fibrous or foam blanket treatments for broadband noise control and thermal insulation. Consequently, it is of interest to further explore the noise control benefit and trade-offs of structurally integrated resonators when combined with various degrees of blanket noise treatment in an aircraft-representative cylindrical fuselage system. In this study, numerical models were developed to predict the effect of broadband and multi-tone structurally integrated resonator arrays on the interior noise level of cylindrical vibroacoustic systems.
2017-06-05
Technical Paper
2017-01-1764
Himanshu Amol Dande, Tongan Wang, John Maxon, Joffrey Bouriez
Abstract The demand for quieter interior cabin spaces among business jet customers has created an increased need for more accurate prediction tools. In this paper, the authors will discuss a collaborative effort between Jet Aviation and Gulfstream Aerospace Corporation to develop a Statistical Energy Analysis (SEA) model of a large commercial business jet. To have an accurate prediction, it is critical to accurately model the structural and acoustic subsystems, critical noise transmission paths, and dominant noise sources for the aircraft. The geometry in the SEA model was developed using 3D CAD models of major airframe and interior cabin components. The noise transmission path was characterized through extensive testing of various aircraft components in the Gulfstream Acoustic Test Facility. Material definitions developed from these tests became input parameters in the SEA model.
2017-06-05
Technical Paper
2017-01-1768
Yong Xu
Abstract The NVH performance is one of the most important concerns in vehicle development. For all-wheel drive (AWD) vehicles and rear-wheel (RWD) drive vehicles, prop shaft is a major transmission component which may cause various NVH problems. This paper focuses on the vehicle NVH problems caused by the second order excitation force of prop shaft. In order to control the NVH performance of the prop shaft efficiently and fundamentally, this work first studied the rotation kinematical characteristics of prop shaft. Then a rigid-elastic coupling model of vehicle driveline was built with the theory of multi-body dynamics. With this model, the sensitive factors that may affect the second order excitation force were investigated. This paper also describes a case study to verify the conclusions which are revealed from the theoretical calculation and the simulation.
2017-06-05
Technical Paper
2017-01-1769
Onkar Gangvekar, Santosh Deshmane
Abstract In today’s automobile market, most OEMs use manual transmission for cars. Gear Shifting is a crucial customer touch point. Any issue or inconvenience caused while shifting gears can result into customer dissatisfaction and will affect the brand image. Synchronizer is a vital subsystem for precise gear shifting mechanism. Based on vehicle application selection of synchronizer for given inertia and speed difference is a key factor which decides overall shift quality of gearbox. For more demanding driver abuse conditions like skip shifting, conventional brass synchronizers have proved inadequate for required speed difference and gear inertia, which eventually results into synchronizer crashing and affects driving performance. To increase synchronizer performance of multi-cone compact brass synchronizer, a ‘Grit blasting process’ has been added. These components tested with an accelerated test plan successfully.
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