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2016-08-02 ...
  • August 2-4, 2016 (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.
2016-04-25 ...
  • April 25-26, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, 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.
2016-04-14
Event
This session will cover intake/exhaust/powertrain and chassis noise and vibration. Papers covering vehicle interior comfort, advanced methods and subjective response are also welcome
2016-04-14
Event
This session will cover intake/exhaust/powertrain and chassis noise and vibration. Papers covering vehicle interior comfort, advanced methods and subjective response are also welcome
2016-04-13
Event
This session will cover intake/exhaust/powertrain and chassis noise and vibration. Papers covering vehicle interior comfort, advanced methods and subjective response are also welcome
2016-04-13
Event
This session will cover intake/exhaust/powertrain and chassis noise and vibration. Papers covering vehicle interior comfort, advanced methods and subjective response are also welcome
2016-04-05
Journal Article
2015-01-9152
André Lundkvist, Arne Nykänen, Roger Johnsson
Abstract Many of the information systems in cars require visual attention, and a way to reduce both visual and cognitive workload could be to use sound. An experiment was designed in order to determine how driving and secondary task performance is affected by the use of information sound signals and their spatial positions. The experiment was performed in a driving simulator utilizing Lane Change Task as a driving scenario in combination with the Surrogate Reference Task as a secondary task. Two different signal sounds with different spatial positions informed the driver when a lane change should be made and when a new secondary task was presented. Driving performance was significantly improved when both signal sounds were presented in front of the driver. No significant effects on secondary task performance were found. It is recommended that signal sounds are placed in front of the driver, when possible, if the goal is to draw attention forward.
2016-04-05
Technical Paper
2016-01-1063
George Nerubenko
Up to 30% of engine noise is delivered by front end pulley combined with torsional vibration damper, and technically it is the main contributor to recorded engine noise level. So the novel solutions in terms of improving the design and performance of torsional vibration damper would help to reduce radically this component of engine noise. The results of dynamical study of patented torsional vibration damper combined with pulley are presented. Design and structure of torsional vibration damper is based on author’s US Patent 7,438,165 having the self-tuning control system for all frequencies in running engine in all operational regimes. Mathematical model has been used for the analysis of the emitting noise of engine having proposed torsional vibration damper. Attention is paid to mitigation of the sound power levels contributing by engine subsystem “end of crankshaft - torsional vibration damper – pulley”.
2016-04-05
Technical Paper
2016-01-0472
Lianhui Wang, Shuming Chen, Dengfeng Wang, Yang Jiang, Jing chen
With the development of modern transportation industry, noise pollution is becoming a serious problem. Thus how to reduce noise becomes a hot topic. The most commonly used method is the use of porous sound absorption materials. There are different ways to predict the sound absorption performance of the materials. One of them is genetic algorithm. It can intuitively find critical information that cannot be found in theory. Genetic algorithm is an excellent simulation method. It acquires the optimal solution by imitating the natural selection and genetic mechanism. Therefore, the solution is more close to the target solution after multiple optimizations. The purpose of the present study is to propose a novel approach applying the genetic algorithm to predict the porous materials' sound absorption properties. In this paper we use the foam as the porous material.
2016-04-05
Technical Paper
2016-01-1296
Yuntao Cao, Dengfeng Wang, Tonghang Zhao, Xining Liu, Chao Li, Hangsheng Hou
The source of noise excitation is different between electric and conventional vehicles due to their distinctive power system architecture. This work focuses on an interior noise contribution analysis using a model established base on the noise path analysis principle. The obtained results show that the structural-borne noise from the road excitation acts as a major contributor to the overall interior noise level, and the structural-borne noise from the powertrain system contributes noticeably as well, whereas the contribution from the electric motor and tire is relatively insignificant.
2016-04-05
Technical Paper
2016-01-1324
Yuntao Cao, Tonghang Zhao, Chao Li, Meng Yang, Hangsheng Hou
The primary noise source of an electric vehicle differs from that of traditional vehicles due to the structural difference in their powertrain systems. Firstly, this work introduces exterior noise test methods for electric vehicles, including a pass-by noise measurement method during acceleration on the proving ground as well as in a semi-anechoic room, and the obtained results base on those two methods from an electric vehicle are compared and analyzed. Secondly, the mechanism of the source, path, and contribution is illustrated, and a model of a path-source-contribution for electric vehicles is established. The model validation is carried out by the correlation of the measured results under real operating conditions and the calculated outcomes. Finally, by using the model, contribution analyses are carried out to identify the primary exterior noise source.
2016-04-05
Technical Paper
2016-01-1317
Peng Wang, Xin Hua, T Wu, David W. Herrin
Insertion loss in one-third or octave bands is widely used in industry to assess the performance of large silencers and mufflers. However, there is no standard procedure for determining the transmission loss in one-third or octave bands using measured data or simulation. In this paper, assuming that the source is broadband, three different approaches to convert the narrowband transmission loss data into one-third and octave bands are proposed. Each method is described in detail. To validate the three proposed approaches, narrowband transmission loss of a simple expansion chamber is converted into one-third and octave bands, and results obtained from the suggested approaches are demonstrated to agree well with one another.
2016-04-05
Technical Paper
2016-01-0478
Yinzhi He, Zhigang Yang, Yigang Wang
The full scale aeroacoustic wind tunnel of Shanghai Automotive Wind Tunnel Center (SAWTC) of Tongji University has been under full operation since 2009 after nearly 5 years construction and commissioning. This facility is designed with nozzle area 27m2 not only for full scale automobile testing of aerodynamics and aeroacoustics, but also for Buses, light trucks, scale train model etc. The maximal wind speed of this wind tunnel can reach 250km/h. One of the highlights is the extremely low background noise of only 61dBA at 160km/h. It is so quiet a wind tunnel first of all in China and contributes very much to the vehicle development of the vehicles marketed in the Chinese market. In this paper, after a short introduction about layout of the full scale aeroacoustic wind tunnel of Tongji University, the special acoustic measures to achieve so low background noise of this wind tunnel are presented as well.
2016-04-05
Technical Paper
2016-01-1295
Atsushi Itoh, ZongGuang wang, Toshikazu Nosaka, Keita Wada
Electric vehicle has quiet in the cabin, but on the other hand, it becomes easy to perceive refrigerant-induced noise in automotive air-conditioning system. In the case of purchasing air-conditioning components from some suppliers separately, it is crucial to verify whether refrigerant-induced noise occurs in system or not before air-conditioning components are assembled. If target noise occurs less frequently, it is difficult to evaluate in a vehicle testing. This paper presents 1D modeling methodology for simulation of refrigerant-induced noise such as self-excitation noise generated by pressure pulsation through thermal expansion valve. A GT-SUITE commercial code was used to develop a refrigerant cycle model, consisting of compressor, condenser, evaporator, thermal expansion valve and connecting pipe network.
2016-04-05
Technical Paper
2016-01-1319
Kimitoshi Tsuji, Katsuhiko Yamamoto
It is important for vehicle concept planning to estimate fuel economy and the influence of vehicle vibration in advance using virtual engine specifications and a virtual vehicle frame. In our former study, we showed the 1D physical power plant model with electrical starter, battery that can predict combustion transient torque, combustion heat energy and fuel efficiency. The simulated result agreed with measured data. For idling stop system, the noise and vibration during start up is important factor for salability of the vehicle. In this paper as an application of the 1D physical power plant model, we will show the result of analysis that is starter shaft resonance and the effect on the engine mount vibration of restarting from idle stop. The power plant was 3.5L 6cyl NA. The power plant model was realized by energy based model using VHDL-AMS. Here, VHDL-AMS is modelling language stored in IEC international standard (IEC61691-6) and can realize multi physics on 1D simulation.
2016-04-05
Technical Paper
2016-01-1320
Sri Siva Sai Meduri, V Sundaram, Sathish Kumar S
Air Induction system (AIS) provides sufficient and clean air to the engine for its desired combustion thereby enhancing engine performance. The ideal design of AIS also reduces the engine noise heard at snorkel which contributes to the cabin noise. Good acoustic expertise and several tests are required to optimize the design of AIS. Multiple resonators are commonly used in passenger cars to attenuate the noise. This paper emphasize on One Dimensional (1D) approach to optimize the resonators in the AIS to meet the functional requirements. In AIS, the flow happens from the snorkel to the engine air intake whereas the sound propagates in the opposite direction. The unsteady mass flow through the intake valves causes pressure fluctuations in the intake manifold and these propagate to intake orifice and are radiated as noise which is heard at snorkel.
2016-04-05
Technical Paper
2016-01-1617
Yoshinobu Yamade, Chisachi Kato, Shinobu Yoshimura, Akiyoshi Iida, Keiichiro Iida, Kunizo Onda, Yoshimitsu Hashizume, Yang GUO
The objective of this research is to predict accurately aeroacoustical interior noise of a car for a wide range of frequency between 100 Hz and 4 kHz. One-way coupled simulations of CFD, structural analysis and acoustical analysis were performed to predict the interior aeroacoustical noise. Statistical Energy Analysis (SEA), which is a traditional method for evaluating transmission of sound and interior sound field, cannot be used for a low frequency range, while the proposed method can be used for a wide range of frequency including a low frequency range. We predicted pressure fluctuations on the external surfaces of a car by computing unsteady flow around a car as the first step. Secondly, the predicted pressure fluctuations were fed to the subsequent structural analysis to predict vibration accelerations on the internal surfaces of the car.
2016-04-05
Technical Paper
2016-01-1306
Valentin Soloiu, Emerald Simons, Martin Muinos, Spencer Harp, Aliyah Knowles, Gustavo Molina
Diesel engines provide the necessary power for accomplishing heavy tasks across the industries, but are known to produce high levels of noise. Additionally, each type of fuel possesses unique combustion characteristics that lead to different sound and vibration signatures. Noise is an indication of vibration, and components under excessive vibration may wear prematurely, leading to repair costs and downtime. New fuels that are sought to reduce emissions, and promote sustainability and energy independence must be investigated for compatibility from a sound and vibrations point-of-view also. In this research, the sound and vibration levels were analyzed for an omnivorous, single cylinder, CI research engine with alternative fuels and an advanced combustion strategy, RCCI. The fuels used were ULSD#2 as baseline, natural gas derived synthetic kerosene, and a low reactivity fuel n-Butanol for the PFI in the RCCI process.
2016-04-05
Technical Paper
2016-01-1355
Jeffrey R. Hodgkins, Walter Brophy, Thomas Gaydosh, Norimasa Kobayashi, Hiroo Yamaoka
Current CAE (computer aided engineering) methods used to develop vehicle interior noise performances have always had the reputation for being inaccurate in predicting acoustic behavior in the mid-frequency range (300 to 1000 Hz). It is in this frequency range where the overall acoustic performance becomes sensitive to not only the contributions of structure-borne noise components, which CAE has proven capable of predicting, but also the growing contributions of air-borne noise components, where CAE usually lacks the capability to accurately reflect the physics involved in complex vibro-acoustic systems. This paper will discuss a study that was undertaken to test the capability of a finite element modeling method that can accurately simulate air-borne noise phenomena in the mid-frequency range. This modeling method was used to create a model of an enclosed simple box-shaped vibro-acoustic system fit with various acoustic trim parts (carpet and under body covers).
2016-04-05
Technical Paper
2016-01-1616
Keiichiro Iida, Kunizo Onda, Akiyoshi Iida, Chisachi Kato, Shinobu Yoshimura, Yoshinobu Yamade, Yoshimitsu Hashizume, Yang GUO
The objective of this research is to predict accurately aeroacoustical interior noise of a car for a wide range of frequency between 100 Hz and 4 kHz. In this study, one-way coupled simulation of computational fluid dynamics (CFD), structural and acoustical analyses were performed to predict flow induced interior noise. Statistical Energy Analysis (SEA), which is a traditional method for evaluating transmission of sound and interior sound field, cannot be used for a low frequency range. In this study, structural and vibrational analysis and acoustical analysis were performed to predict the interior noise. This proposed method can be used for a wide range of frequency between 100 Hz and 4 kHz including a low frequency range. In this paper, the structural and vibrational analyses were performed by using the finite element method (FEM). The acoustical analysis results were compared the wind tunnel experimental results.
2016-04-05
Technical Paper
2016-01-0488
Takashi Izawa, Motohiko Koushima
The sliding bearing generally used for engine main bearing in passenger vehicles are known to show a reduction in seizure limit performance relative to ideal conditions when the bearing are subjected to the influence of various noise factor (factor exerting negative influence) under actual operating conditions. Recent passenger vehicle engine development has sought to meet the demand for higher fuel economy and specific torque by reducing the width of the bearing and increasing the input load. The environment in which bearing are used is growing ever more demanding. The influence of noise factor on seizure limit performance is believed to be on an increasing trend in conjunction with this change. The importance of ascertaining that influence is growing greater, but few attempts have been made to verify those factors quantitatively.
2016-04-05
Technical Paper
2016-01-1325
Masanori Watanabe, Yosuke Tanabe, Naoki Yoneya
Recently, the need to reduce noise generated by machines has been increasing because people are generally becoming more environmentally aware. In order to reduce noise efficiently, noise source localization technology by using microphone arrays is applied to many machines. However, it is difficult to identify noise and excitation sources of vehicle components because the size of noise and excitation source is very small compared to other machines. Therefore, the technical issue of vehicle components is to identify the excitation source finely to reduce noise effectively. Hence, the system which can identify the excitation sources has been developed by combining measurement and analysis. This enables to solve noise and vibration problems at an early stage of development and shorten the development period. Results are as follows, (1) Multi physical quantities and multi channel measurement system has been developed.
2016-04-05
Technical Paper
2016-01-1309
Yingping Lv, Yongchang Du, Yujian Wang
In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. The methods are based on a new closed-loop coupling disc break model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived. Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode. Substructure modal parameters sensitivity analysis calculates the sensitivity of each component’s modal frequencies and shape coefficients to the real part of eigenvalues. Finally, the presented analysis methods are applied to analysis a high frequency squeal problem of a squealing disc brake.
2016-04-05
Technical Paper
2016-01-1094
Fang Liao, Weimin Gao, Yan Gu, Fei Kang, Yinan Li, Cheng Wang
Generally, the gear rattle noise prediction models are composed of the mass and stiffness elements. The proposals are about the gear inertia or backlash and the shaft inertia, stiffness, but there are many detailed designs in the same inertia, stiffness or backlash conditions. Therefore, these proposals cannot guide detailed designs. These models only investigate the rattle in the rotating degree, and ignore rattle contribution in the radical and axial directions. Those prediction models only consider one or several factors which affect the rattle noise performance. It is difficult to predict the influence of individual factor and multi-factors coupling on the gear rattle noise in a rattle simulation model.
2016-04-05
Technical Paper
2016-01-1294
Jonggyu KIM, Pyoung Beom Kim, YoungChan Lee, Sunghee Jung, Byeong-Ug Choi
This paper presents the characteristics of a 3 Cylinder CVT vehicle and a process to improve fuel economy and reduce noise and vibration. To increase the lock-up area of damper clutch for the high fuel economy and to decrease booming and vibration affected by lock-up, chassis systems of a driveline and structure resonance characteristics are studied by experiment and simulation. CVT software calibration parameters are optimized for fuel economy and NVH. With This Study, the lock-up area has been increased by 300RPM and the fuel economy has been improved by approximately 1%, while the NVH characteristic is almost same.
2016-04-05
Technical Paper
2016-01-1321
Masahiro Fukazawa, Tsuyoshi Murao, Shingo Unigame
The CAE method to predict the vibration transfer function of the fluid engine mount on a vehicle with sufficient precision and calculation time without prototype cars was developed. The transfer function is given in the following steps.First, rubber deformation form under the power train weight loaded must be predicted. It’s obtained by using a reduction model of engine mount, as a unit, which doesn’t have its fluid sealed inside, with the technique to get static spring characteristics in a non-linear relationship. Second, Young’s modulus and structural damping coefficient for the deformed rubber must be given. As for these characteristics, ignoring the relations between these values and strain, the constant values are used. This considerably reduced computation time and model size.Next, the reduction model and the fluid model which actually the engine mount has must be combined to express actual product.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
The knocking noise is a transient structural noise triggered by the shock absorber's piston rod vibrations that excites the vibration of chassis components. Piston rod vibrations can be caused by valves motion (opening and closing) and dry friction during stroke inversions. This study investigates the shock absorber knocking noise on a twintube gas-filled automotive shock absorber and the aim is to define an acceptance criterion (threshold level) for a sample check of the component. If infact the damper derives from a large mass production, may happen that small differences in the assembly might lead to different behaviours resulting in higher or lower levels of knocking noise. To achieve the goal, experimental tests were carried out at various excitation frequencies and amplitudes. Test were performed using a oleodynamic test bench monitoring displacement and force; accelerometers were placed in proximity of the rebound valve, on the body of the damper and on the piston rod.
2016-04-05
Technical Paper
2016-01-1069
Masayoshi Otaka, Taro Kasahara, Kenichi Komaba
As a means of further improving combustion efficiency of gasoline engine, an increase in compression ratio, which enhances the risk of knocking, is thinkable. To optimize engine combustion parameters, a technology that can precisely detect knocking is desirable. Presently skillful experts have been evaluating knocking subjectively by listening to radiation noise so far. The authors developed a device that can precisely detect knocking by means of processing sound signals, which are captured by a high-performance microphone that is sensitive in the wide frequency range. Shock waves induced by knocking cause in-cylinder gas vibrations that emits metallic hit noises from the outer engine wall. We studied how to identify the feature values of frequency characteristics when knocking occurs, under the assumption that the engine radiation noise includes more than 2nd-order harmonic components with respect to the basic frequency of the in-cylinder gas vibration mode.
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