Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 7876
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
2017-01-1842
Akin Oktav, Cetin Yilmaz, Gunay Anlas
As a countermeasure to trunk lid slam noise, reactive openings are used in the trunk cavities of passenger vehicles. In sedans trunk and cabin cavities are coupled acoustically through discontinuities on the parcel shelf and/or the rear seat. In such a case, these openings behave as if necks of a Helmholtz resonator, which in turn change the acoustic response of the system, accordingly. The Helmholtz resonator effect of the trunk cavity is discussed analytically through a simplified cavity model. A case study is also given, where the acoustic response of a sedan is analyzed through the computational model that considers the resonator effect. Sound pressure level results show that instant pressure drops and damping effects observed in the acoustic response can be explained with the resonator effect. Results obtained from the computational model of the sedan are verified by road test measurements
2017-06-05
Technical Paper
2017-01-1872
Masao Nagamatsu
The almost current sound localization methods do not have enough resolution in low frequency sound localization. To overcome this disadvantage, I am now developing a new sound localization method, Double Nearfield Acoustic Holography (DNAH) method. This method is a converted method of conventional Nearfield Acoustic Holography (NAH) method. In this proposing method, the resolution of low frequency sound localization is improved by using sound propagation information on doubled measurement planes. To prove the performance of proposing method, the basic experiments with variable conditions are conducted. In these experiments, the small speakers are used as sound sources. In this paper, to discuss the ability to apply to actual industry, the effect of measurement distance from sound source is explained. Some experimental results with changing measurement distance are shown in this paper.
2017-06-05
Technical Paper
2017-01-1811
Jouji Kimura, Tatsuya Tanaka, kenjiro hakomoto, Kousuke Kawase, Shinichiro Kobayashi
This paper describes based on the mechanism of whirl resonance about the characteristic of serious bending stress which occurred in the crankshaft rear. The following steps to prove that the bending stress is caused by whirl resonance of the crankshaft rear end. At first, the authors showed that the resonance frequency of bending stress for forward whirl which takes place in the same direction as crankshaft rotation increases with the increasing engine speed, and the resonance frequency of bending stress for reverse whirl which takes place in the reverse direction as crankshaft rotation decreases with the increasing engine speed. Secondly, it was found out that there are two groups, the correlation between the resonance frequency and the resonance engine speed of the measured bending stresses in the crankshaft rear. One is the group that the resonance frequency increases with the increasing engine speed.
2017-06-05
Technical Paper
2017-01-1824
Reza kashani, Karthik S. Jayakumar, Neville Bugli, Jeff Lapp
Passive, tuned acoustic absorbers, such as Helmholtz resonators (HR) or quarter-wave tubes, are commonly used solutions for abating the low-frequency tonal noise in air induction systems. Since absorption at multiple frequencies is required, multiple absorbers tuned to different frequencies are commonly used. Typically, the large size and multiple numbers of these devices under the hood is a packaging challenge. Also, the lack of acoustic damping narrows their effective bandwidth and creates undesirable side lobes. Active noise control could address all of the above-mentioned issues. Most active noise control systems use feed-forward adaptive algorithms as their controllers. These complex algorithms need fast, powerful digital signal processors to run. To ensure the convergence of the adaptation algorithm, the rate of adaptation should be made slow.
2017-06-05
Technical Paper
2017-01-1883
Arnaud Duval, Guillaume Crignon, Mickael Goret, Maxime Roux
The lightweighting research on noise treatments since years tends to prove the efficiency of the combination of good insulation with steep insulation slopes with broadband absorption, even in the context of bad passthroughs management implying strong leakages. The real issue lies more in the industrial capacity to adapt the barrier mass per unit area to the acoustic target from low to high segment or from low petrol to high diesel sources, while remaining manipulable. The hybrid stiff insulator family can realize this easily with hard felts barriers backfoamed weighting from 800 g/m² to 2000 g/m² typically with compressions below 10 mm. Above these equivalent barrier weights and traditional compressions of 7 mm for example, the high density of the felts begins to destroy the porosity and thus the absorption properties (insulation works anyway here, whenever vibration modes do not appear due to too high stiffness…).
2017-06-05
Technical Paper
2017-01-1843
Taejin shin, Jaemin Jin, Sang Kwon Lee, Insoo Jung
This paper presents the influence of radiated noise from engine surface depending on assembly condition between engine block and oil pan. At the first, force at the crank bearing is obtained from multi-body dynamics model. Secondly, modal analysis is operated to define mode contribution and modal participation factors at the Structure – FEM model for virtual cylinder block. Thirdly, the radiated noise is calculated by Acoustic-FEM. Above procedure is applied at rigid connection model and sandwich panel connection model. Connection properties are applied between engine block and oil pan. Finally, the sound quality of the radiated noise at each condition are compared.
2017-06-05
Technical Paper
2017-01-1848
Richard DeJong
From 1983 to 1995, Richard H. Lyon published several papers on Statistical Phase Analysis, showing that the average phase of the transfer functions in complex systems grows with frequency in proportion to the modal density of the system. In one dimensional systems this phase growth is the same as that of freely propagating waves. However, in two and three dimensional systems this phase growth is much larger than the corresponding freely propagating wave. Recent work has shown that these phase growth functions can be used as mode shape functions in discrete system models to obtain results consistent with Statistical Energy Analysis. This paper reviews these results and proposes naming the statistical mode shape functions in honor of Lyon.
2017-06-05
Technical Paper
2017-01-1840
Thierry Bourdon, Rainer Weber, Johann massinger PhD
Nowadays, the automotive industry is increasingly facing of reducing vibration & noise in the vehicle. More particularly on the engine area, the development of fuel components based on high pressure pumps, rails, any pipes and injectors are a subject of a particular NVH attention. The use of modern digital techniques such as 3D finite element vibroacoustic, leads to use virtual prototyping as complementary to traditional real hardware prototypes development. Among interest, number of iterative loops to reach a best design brings an important value to new product development with an optimized cost. Basically the core part of virtual prototyping is about 3D finite element models for each component. It is quite challenging to establish these models, as they must mimic the entire physical phenomenon of real structure borne hardwares sound in the whole audible frequency range.
2017-06-05
Technical Paper
2017-01-1775
Mark A. Gehringer, Robert Considine, David Schankin
This paper describes recently developed test methods and instrumentation to address the specific noise and vibration measurement challenges posed by large diameter single-piece tubular aluminum propeller shafts with high modal density. The application described in this paper is a light duty truck, although the methods described are applicable to any rotating shaft with similar dynamic properties. To provide a practical example of the newly developed methods and instrumentation, rotating and non-rotating data were acquired in-situ for several propeller shafts of varying construction, including both lined and unlined shafts. Data were also acquired with and without a torsional tuned vibration absorber attached to the driveline. The example data exhibit features that are uniquely characteristic of large diameter single-piece tubular shafts with high modal density, including the particular effect of shaft rotation on the measurements.
2017-06-05
Technical Paper
2017-01-1773
Jing Yuan
The dual phase twin synchronous drive has been developed for belt noise reduction. Two identical synchronous belts are arranged parallel side by side with one tooth staggered against other by the half pitch. The noise cancellation effect is achieved as one belt tooth engagement coincides with the other belt tooth dis-engagement. A center flange is used as a divider to prevent the belts contacting each other along the axial direction during their entrance and exit of the sprocket. An overall 20 [dBA] noise reduction has been achieved with the dual phase twin belt system compared to an equal width single belt counterpart. The vibration amplitude of the hub load is also reduced which is directly correlated to the structural borne noise. Comparing to the related dual phase helical tooth belt, also known as the eagle belt trade marked by Goodyear, the dual phase twin belt is superior in torque carrying capability; and is on par with noise mitigation.
2017-06-05
Technical Paper
2017-01-1784
Guillaume Baudet
Automotive wind noise’s physic is complex : noise for passengers depend of : - acoustic transfer function in the cabin - transfer loss of seals and panels - first of all, exterior loading due to the flow around the vehicle For some years, we know that the exterior loading can and must be split in two parts : - Hydrodynamic (or turbulent) loading with high wave number pressure field - Acoustic loading with low wave number pressure field In simulation people start to separate the two pressure fields by complex signal processing. But in real life test, there is no simple method to do so. In this paper we present an inverse method, call “Panel Inverse Method” (PIM) which can extract the low wave number loading measured on a vehicle panel. The method may be known with the French “RIFF” name. It is based on acceleration measurement of the panel to calculate the pressure which create panel’s motion : that’s typically an inverse method.
2017-06-05
Technical Paper
2017-01-1785
Paul Bremner, Scott Clifton, Chris Todter
Measurements of interior wind noise sound pressure level have shown that dBA and Loudness are not adequate metrics of wind noise sound quality due to non-stationary characteristics such as temporal modulation and impulse. A surface microphone array with high spatio-temporal resolution has been used to observe the corresponding non-stationary characteristics of the exterior aero-acoustic loading. Wavenumber filtering is used to observe the unsteady character of the low wavenumber aero-acoustic loading components capable of exciting glass vibration and transmitting sound.
2017-06-05
Technical Paper
2017-01-1783
Chris Todter, Olivier Robin, Paul Bremner, Christophe Marchetto, Alain Berry
Fluctuating surface pressure measurements using microphone arrays are still challenging, especially in an automotive context with cruising speeds around Mach 0.1. The separated turbulent boundary layer excitation and the side mirror wake flow generate both acoustic and aerodynamic components, which have wavenumbers that differ by a factor of approximately 10. This calls for high spatial resolution measurements to fully resolve the wavenumber-frequency spectrum. In SAE paper 2015-01-2325, the authors reported a micro-electro-mechanical (MEMS) surface microphone array that successfully used wavenumber analysis to quantify acoustic versus turbulence loading. It was shown that the measured surface pressure at each microphone could be strongly influenced by self noise induced by the microphone ”packaging”, which can be attenuated with a suitable windscreen.
2017-06-05
Technical Paper
2017-01-1769
Onkar Gangvekar, Santosh Deshmane
In today's automobile market, most of OEM's uses manual transmission for Cars. Gear Shifting is a crucial customer touch point. Any issue or inconvenience caused while shifting gear 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 the 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 and 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 are tested with Accelerated test plan successfully.
2017-06-05
Technical Paper
2017-01-1801
Sivasankaran Sadasivam, Aditya Palsule, Ekambaram Loganathan, Nagasuresh Inavolu, Jaganmohan Rao M
Powertrain is the major source of noise and vibration in commercial vehicles and has significant contribution on both interior and exterior noise levels. Sound intensity mapping technique identifies and quantifies the spatial distribution of energy radiated by powertrain by means of measurements close to its surface. Based on the quantification, noise sources are ranked, through which Oil sump is identified as one of the major contributors for powertrain noise radiation. Accurate prediction of oil sump modal characteristics is more critical in determining the sound power radiation. This paper discusses about capability of numerical approach in predicting more realistically, oil sump modal characteristics with fluid-structure interaction and consequent verification with experimental modal test results. With this validated model, radiated sound power level of the oil sump has been predicted using acoustic finite element method.
2017-06-05
Technical Paper
2017-01-1820
Martin Sopouch, Josip Hozmec, Alessandro Cadario
This paper presents a simulation environment and methodology for noise and vibration analyses of a driven rear axle in a bus application, with particular focus on medium to high frequency range (400 Hz to 3 kHz). The workflow demonstrates structure borne noise and sound radiation analyses. The fully flexible Multi–Body Dynamics (MBD) model - serving to cover the actual mechanical excitation mechanisms and the structural domain – includes geometrical contacts of hypoid gear in the central gear and planetary gear integrated at hubs, considering non-linear meshing stiffness. Contribution of aforementioned gear stages, as well as the propeller shaft universal joint at the pinion axle, on overall axle noise levels is investigated by means of sensitivity analysis. Based on the surface velocities computed at the vibrating axle-housing structure the Wave Based Technique (WBT) is employed to solve the airborne noise problem and predict the radiated sound.
Viewing 1 to 30 of 7876

Filter

  • Range:
    to:
  • Year: