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Viewing 1 to 30 of 7342
2015-08-04 ...
  • August 4-6, 2015 (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.
2015-06-26 ...
  • June 26, 2015 (8:30 a.m. - 4:30 p.m.) - Grand Rapids, Michigan
Training / Education Classroom Seminars
Most muffler design in the automotive industry is accomplished by using "cut-and-try" methods that rely on what has worked in the past and/or extensive full-scale testing on engines for validation. New computer software aimed at muffler design can shorten the design cycle and yield more effective results. This four hour seminar provides an introduction to the behavior of mufflers and silencers including a description of the two-port approach to muffler design. This seminar covers the acoustic simulation of muffler and silencer systems and the use of experimental methods to measure muffler performance....
2015-06-26 ...
  • June 26, 2015 (8:30 a.m. - 4:30 p.m.) - Grand Rapids, Michigan
  • October 9, 2015 (8:30 a.m. - 4:30 p.m.) - Charleston, South Carolina
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...
2015-06-25 ...
  • June 25-26, 2015 (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...
2015-06-22
Event
This session is to present numerical and experimental work pertaining to noise due to flow around the vehicle body, such as flow-induced interior noise, flow over protrusions, sunroofs, windows, noise from ventilation systems, or flow noise in exhaust system. Papers on aerodynamics alone without sound are excluded. Numerical studies may include new models or models based on existing theory as long as they are adequately supported by experimental or theoretical verifications.
2015-06-22
Event
This session covers noise sources, measurement techniques, noise attenuation strategies, case studies, prediction and modeling methods, and community regulations related to drive-by noise.
2015-06-22
Event
This session is focused on the vehicle body interior noise issues caused by friction and/or impact due to the vibration of interfacing components. The papers in this session will investigate those issues through the best practice of analytical and experimental applications.
2015-06-22
Event
This session covers noise and vibration sources and paths within a vehicle (automobiles, trucks and recreational vehicles). Example of noise sources included are HVAC system, electric motor powered mechanisms and door closure and example of vibration sources are road and engine. Also included are Whole Body and Hand Arm Vibration experienced by professional drivers as well as acoustical design factors of audio, infotainment, and hands free devices.
2015-06-22
Event
This session addresses the strategies and methods for implementing active noise and vibration control in a vehicle. It will cover sensors and transducers, feedback systems, control algorithms, software for active control, noise and vibration cancellation devices, noise and vibration measurement systems, and case studies.
2015-03-17 ...
  • March 17-26, 2015 (4 Sessions) - Live Online
  • September 15-24, 2015 (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....
2014-11-11
Technical Paper
2014-32-0105
Atsushi Maruyama, Gaku Naoe
Abstract For a small general purpose engine, the authors have studied on “combustion noise”, the mechanical noise originating from combustion. The purpose of this study is to clarify the mechanisms of combustion noise generation. The engine used in this study was a 4-stroke air-cooled single-cylinder engine with the typical characteristics of 3.5 kW-class small general purpose engines, which was specifically designed for experiments. We analyzed the operational behaviors of parts such as the crankshaft, the flywheel and the crankcase during the time of occurrence of combustion noise. Results of the analysis showed that the primary component of combustion noise in small general purpose engines is radiated from the flywheel connected to the crankshaft, and that the vibration mode that radiates the noise is excited by bending deformation of the crankshaft under explosion load. Based on these results, this paper will also discuss the effect of the stiffness of the main bearings on combustion noise.
2014-11-11
Technical Paper
2014-32-0119
Diego Copiello, Ze Zhou, Gregory Lielens
Abstract This paper addresses the numerical simulation of motorcycle exhaust system noise using a transfer matrix method (TMM) supporting high order analytical acoustic modes representation combined with finite element method (FEM) included in the Actran software, R15. In the state-of-the-art of hybrid TMM/FEM approach the main assumption consists in a 1D plane wave acoustic propagation in the components connections which is intrinsically limiting the maximum frequency of the analysis. In motorcycle exhaust systems this limitation is even stronger because typical geometries exhibit strong curvatures and bends causing the scattering of the acoustic wave into higher order modes. Therefore, results might be erroneous even at frequencies at which only the plane wave is expected to be propagating. The improved transfer matrix method presented in this paper overcomes this limitation allowing to increase the range of applicability of this method. Specifically, the method is theoretically described and then validated on a set of test cases directly derived from a typical motorcycle exhaust system.
2014-11-11
Technical Paper
2014-32-0121
Kazuhiko Tanaka, Haruomi Sugita, Hibiki Saito, Masahiko Sekita
Abstract Recently, it has been widely practiced in motorcycle developments that the same type of engine is commonly applied to various vehicle categories. Accordingly, it is drawing more attention to develop the methodology for creating the best suitable sound for each individual vehicle category regardless of restriction from the engine configurations. In our study, we aimed to establish a procedure to control exhaust sounds beyond the borders across the inherent sound qualities originated from their engine configurations. Firstly, we conducted subjective tests in order to extract essential factors, depicted by adjectives that appear in verbal expressions commonly used to illustrate sound qualities in general. The results enabled us to conduct quantitative evaluations of the exhaust sound qualities of various motorcycles. Next, we clarified the relationships among the individual factors of sound qualities under our study and physical parameters in waveforms of the sounds. Finally, we tried to design the target sound quality having required physical parameters by using a one-dimensional simulation tool.
2014-11-11
Technical Paper
2014-32-0120
Sara Gronchi, Riccardo Maccherini, Raffaele Squarcini, Fabio Guglielmo, Emanuela Ligarò
Abstract In the modern engine of both small and large size, the acoustic emission is a very important matter increasingly studied as per specific international standards. This paper presents the study of the acoustic emission of a hydraulic rotary oil pump by means of measurement techniques and numerical approaches. This activity aims at showing a complete test-case in which both methods are used to face a noise issue and highlighting also the “weight” of the hydraulic excitation in both cases. In particular, an oil pump has been completely characterized on a test bench to verify the hydraulic performances and the noise radiation. A structural modification has been suggested with the target of altering the noise spectrum of the pump, achieving an optimization of the noise generation. From this assumption, experimental and numerical activities have started in parallel. Measurements have been carried out by means of the intensimetric method and supported also by conventional acquisitions performed with hydraulic pressure transducers, accelerometers and microphones.
2014-11-11
Technical Paper
2014-32-0129
Giancarlo Chiatti, Erasmo Recco, Ornella Chiavola, Silvia Conforto
Abstract 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 contribution of the combustion event to be isolated.
2014-11-11
Technical Paper
2014-32-0132
Hiroki Ikeda, Norimasa Iida, Hiroshi Kuzuyama, Tsutomu Umehara, Takayuki Fuyuto
Abstract A combustion method called Noise Canceling Spike (NC-Spike) Combustion [1, 2] has been reported in the co-author's previous paper, which reduces combustion noise in PCCI with split injection. This NC-Spike Combustion uses interference of the following “spike” of pressure rise on the preceding peak of pressure rise. The overall combustion noise is reduced by lowering the maximum frequency component of the noise spectrum. The period of this frequency is two times of the time interval between the two peaks of the pressure rise rate. This maximum load range of conventional PCCI combustion is limited by the combustion noise, since the maximum pressure rise rate increases as the amount of injected fuel increases. The NC-Spike Combustion has a potential to extend of the operating range of PCCI combustion. In this paper, we investigated feasibility and controllability of the two-peak heat release rate during high temperature heat release by adding fuel in the adiabatic compression process of pre-mixed gas.
2014-10-27 ...
  • October 27-31, 2014 (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 practice. 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...
2014-10-27 ...
  • October 27-31, 2014 (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 practice. 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...
2014-10-24
Standard
J1535_201410
This SAE Standard establishes uniform test procedures for the defrosting systems of off-road, self-propelled work machines used in construction, general purpose industrial, agricultural, and forestry machinery as referenced in table one of this document. It includes tests that can be conducted with uniform test equipment in commercially available laboratory facilities, as well as in an appropriate outdoor environment.
2014-10-13
Technical Paper
2014-01-2863
Jouji Kimura, Shinichiro Kobayashi, Katsuhiro Hoshina, Kousuke Kawase, Koji Matsui, Atsushi Yamamoto
Abstract This paper describes the characteristics and mechanism of crankshaft impact noise that radiates from the cylinder body at full load medium engine speeds, based on the mechanism for axial vibration of crankshaft coupled with torsional vibration of crankshaft.
2014-10-13
Technical Paper
2014-01-2676
Takayuki Fuyuto, Masahiro Taki, Reiko Ueda, Yoshiaki Hattori, Hiroshi Kuzuyama, Tsutomu Umehara
Abstract An author's previous studies addressed a combustion system which reduces emissions, noise, and fuel consumption by using PCCI with the split injection of fuel. This concept relies on the premixed combustion of the first injected fuel and accelerated oxidation by the second injected fuel. Although this combustion system requires the optimization of the timing of the second injection, the details of how noise and emissions are reduced have not been elucidated. In this paper, the authors explain the mechanism whereby emissions and noise are reduced by the second injection. In-cylinder visualizations and numerical simulations both showed an increase in smoke and CO as the second injection timing was advanced, as induced by the inhibited oxidation of the rich flame. When the second injection timing is excessively retarded, the amount of soot forming around the near-nozzle increased. The second fuel injection at the optimum timing can mix with the air in the inner-region of the cavity, such that no soot is formed in the near-nozzle region.
2014-10-13
Technical Paper
2014-01-2864
Daniela Siano, Fabio Bozza, Luigi Teodosio, Vincenzo De Bellis
This paper reports 1D and 3D CFD analyses aiming to improve the gas-dynamic noise emission of a downsized turbocharged VVA engine through the re-design of the intake air-box device, consisting in the introduction of external or internal resonators. Nowadays, modern spark-ignition (SI) engines show more and more complex architectures that, while improving the brake specific fuel consumption (BSFC), may be responsible for the increased noise radiation at the engine intake mouth. In particular VVA systems allow for the actuation of advanced valve strategies that provide a reduction in the BSFC at part load operations thanks to the intake line de-throttling. In these conditions, due to a less effective attenuation of the pressure waves that travel along the intake system, VVA engines produce higher gas-dynamic noise levels. The worsening of the engine gas-dynamic performance can be compensated with a partial re-design of the air-box device, without significantly penalizing the engine power output.
2014-09-30
Technical Paper
2014-01-2317
Rahul Ramola, G Senthilkumar, P Kannan, Muralidharan Chennakrishnan
Abstract The demand for comfort level in commercial vehicles is steadily increasing. Hence, fine-tuned performance parameters and attributes are required to fulfill the expectations from these vehicles. Refinement of noise and vibration without affecting performances of sub-systems and components has become extremely challenging with increasing customer requirements. This paper presents an approach to identify and reduce the high level whistling noise that was perceived in the passenger compartment while the vehicle was accelerated above 50 kmph. Interior noise measurements in static engine run-up condition reveal that the whistling noise is of specific order. Since, whistling noise is related to aerodynamic response of components, engine cooling fan, turbo charger, alternators and compressors were suspected. Using order tracking and near field measurements, HVAC alternator was confirmed as the main cause for whistling noise. Noise measurements confirmed that orders related to alternator cooling fan became dominant above 50 kmph.
2014-09-30
Technical Paper
2014-01-2318
Masahiro Akei, Takayuki Koizumi, Nobutaka Tsujiuchi, Takayuki Yamauchi
Abstract This paper describes an identification of a sound source model for a diesel engine installed on an agricultural machine by Inverse-Numerical Acoustic analysis (INA), and the applicability of the identified sound source model. INA is a method to identify surface vibrations from surrounding sound pressures. This method is applicable for a complicated-shaped sound source like an engine. In order to confirm the accuracy of the identified sound source model, the surface vibrations of the engine are compared with the measured results. Moreover, in the condition of the simulated engine room, the surrounding sound pressure levels of the engine are predicted using the sound source model and the boundary element method (BEM). For the verification of the prediction accuracy, the surrounding sound pressures of the engine are measured using the testing device which simulated actual engine room, namely an enclosure. As a result, the sound source model of the diesel engine is identified accurately using the INA.
2014-09-28
Technical Paper
2014-01-2482
Meechai Sriwiboon, Nipon Tiempan, Kritsana Kaewlob, Seong Kwan Rhee
The influence of processing conditions on Low-Copper NAO disc pads were investigated as part of an effort to develop Low-Copper disc pad formulations as this kind of information is not readily available in open literature. Processing conditions as well as formulation modifications are found to influence friction, pad wear, disc wear and brake squeal. Low-Copper disc pads for pick-up trucks, equivalent to an OE pad, are developed. It is also found that brake squeal measured during the SAE J2522 (AK Master) Performance testing is related to the combined total wear rate of the disc plus the inner/outer pads or the disc wear rate alone, and that there is a threshold wear rate, above which brake squeal increases rapidly.
2014-09-28
Technical Paper
2014-01-2491
SeongJoo Lee, JooSeong Jeong, ShinWook Kim, ShinWan Kim, Seong Rhee
A previous investigation showed that minor variations in alloying elements in gray cast iron disc contributed to measurable differences in friction and disc wear. This investigation was undertaken to find out if and how the increased friction and disc wear might affect brake squeal. The SAE J2522 and J2521 dynamometer procedures as well as an OEM noise dynamometer procedure and a chassis dynamometer noise procedure were used to find out if a correlation between disc wear and brake squeal could be discovered. In all cases, as the wear rate of a disc increases under a given set of test conditions, disc material transfer to the pad surface increases, which results in increased friction and brake squeal. Also a good method to detect disc variability (disc to disc, within a disc) is discussed.
Viewing 1 to 30 of 7342

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