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Viewing 181 to 210 of 8700
2014-04-16
Article
dSPACE offers a flexible solution for hardware-in-the-loop testing of electric motors, combining Scalexio architecture with a programmable FPGA board and scalable electronic load.
2014-04-16
Article
The latest release of the MapleSim toolbox from Maplesoft expands control design capabilities and supports parameterized controllers for improved flexibility.
2014-04-16
Article
The all-new sports car poses a crucial question: Is it too clever by half? Dr. Andre Ebner, who heads the company’s development of onboard systems, argues very strongly that it is not.
2014-04-15
Article
With its i3 slated to reach U.S. customer hands in early May, BMW is ramping up production of its first mass-produced all-electric vehicle.
2014-04-14
Article
Customers want quieter cabins, but industry trends are working against the engineers who strive to reduce noise, vibration, and harshness.
2014-04-14
Article
Backed by the world’s fifth-fastest computer, Argonne’s new VERIFI service combines unique test facilities along with focused expertise to help engine developers.
2014-04-09
Article
Misfire detection is most difficult, SAE Congress panel tells attendees, and overall emissions diagnosis is harder than with passenger cars and light-duty trucks.
2014-04-07
Article
Atego Vantage is an integrated solution combining model-based systems and software engineering with asset-based modular design.
2014-04-07
Article
Elysium’s CADfeature 11.3 is a feature-based program for repairing, migrating, and reporting on product engineering data in manufacturing.
2014-04-07
Article
Meggitt Sensing Systems introduces a line of Endevco general purpose isotron IEPE accelerometers designed to meet the needs of various test applications.
2014-04-07
Article
Multiquip recently chose Exa to evaluate and reduce noise propagation from its containerized power generators.
2014-04-07
Article
The Maulflex conduit system from TE Connectivity is a lightweight, flexible, customizable shielded electrical conduit system for rugged environments.
2014-04-07
Article
XCal-View software from Renishaw offers improved functionality and flexibility for laser calibration data analysis.
2014-04-04
Article
According to CD-adapco's Frederick Ross, the first, and most difficult, stage in the construction of a virtual prototype is the process of pulling together all of the individual CAD parts that define a vehicle.
2014-04-01
Article
Palmer Wahl Instrumentation Group’s Wahl DST500-FM temperature indicator with fixed probes is a high-accuracy, wide-range thermometer designed for hazardous locations where accurate and reliable temperature monitoring is critical.
2014-04-01
Article
Dakota Instruments’ 6A03 acrylic flow meters are offered with interchangeable direct reading scales for air, water, argon, oxygen, carbon dioxide, nitrogen, helium, and hydrogen.
2014-04-01
Collection
This technical paper collection covers intake/exhaust/powertrain and chassis noise and vibration.
2014-04-01
Collection
This technical paper collection sets out to reflect the recent advances on the research, development and practices of Powertrain NVH treatment. The coverage includes: engine, engine subsystem and components noise and vibration; powertrain systems noise measurement and instrumentation; powertrain systems noise analysis.
2014-04-01
Technical Paper
2014-01-1364
Ornella Chiavola, Giancarlo Chiatti, Erasmo Recco
Abstract Many studies have demonstrated that an efficient control of the combustion process is crucial in order to comply with increasingly emerging Diesel emission standards and demanding for reduced fuel consumption. Methodologies based on real-time techniques are imperative and even if newly sensors will be available in the near future for on-board installation inside the cylinder, non intrusive measurements are still considered very attractive. This paper presents an experimental activity devoted to analyze the noise emission from a small displacement two-cylinder Diesel engine equipped by HPCR (high pressure common rail) fuel injection system. The signals acquired during stationary operation of the engine are analyzed and processed in order to highlight the different sources contributing to the overall emission. Particular attention is devoted to the specific samples of the signal that are mainly caused by the combustion process in order to extract the combustion contribution.
2014-04-01
Technical Paper
2014-01-1293
Gen Shibata, Hirooki Ushijima, Hideyuki Ogawa, Yushi Shibaike
Abstract When fuel is vaporized and mixed well with air in the cylinder of premixed diesel engines, the mixture auto-ignites in one burst resulting in strong combustion noise, and combustion noise reduction is necessary to achieve high load premixed diesel engine operation. In this paper, an engine noise analysis was conducted by engine tests and simulations. The engine employed in the experiments was a supercharged single cylinder DI diesel engine with a high pressure common rail fuel injection system. The engine noise was sampled by two microphones and the sampled engine noise was averaged and analyzed by an FFT sound analyzer. The engine was equipped with a pressure transducer and the combustion noise was calculated from the power spectrum of the FFT analysis of the in-cylinder pressure wave data from the cross power spectrum of the sound pressure of the engine noise.
2014-04-01
Technical Paper
2014-01-1269
Julie Blumreiter, Chris Edwards
Abstract There is significant motivation to extend the operating range of naturally aspirated HCCI combustion to high load (8-12 bar IMEP) to attain a combustion strategy with the efficiency benefits of HCCI but without the lost power density of a lean or highly diluted charge. Currently, the high-load limit of HCCI combustion is imposed by a phenomenon commonly known as ringing. Ringing results when the kinetically-driven autoignited combustion process proceeds in such a way as to form strong pressure waves which reverberate in the engine. Inhomogeneities and gradients in mixture reactivity lead certain regions to react ahead of others, and as a result, coupling can occur between a pressure wave and the reaction front. This paper seeks first to sort several related but distinct issues that impose the high load limit: ringing, engine damage, peak in-cylinder pressure, peak rate of pressure rise, and engine noise.
2014-04-01
Journal Article
2014-01-1272
Jeremie Dernotte, John E. Dec, Chunsheng Ji
This article presents an investigation of the sources combustion-generated noise and its measurement in HCCI engines. Two cylinder-pressure derived parameters, the Combustion Noise Level (CNL) and the Ringing Intensity (RI), that are commonly used to establish limits of acceptable operation are compared along with spectral analyses of the pressure traces. This study focuses on explaining the differences between these two parameters and on investigating the sensitivity of the CNL to the ringing/knock phenomenon, to which the human ear is quite sensitive. Then, the effects of independently varying engine operating conditions such as fueling rate, boost pressure, and speed on both the CNL and RI are studied. Results show that the CNL is not significantly affected by the high-frequency components related to the ringing/knock phenomenon.
2014-04-01
Technical Paper
2014-01-1043
Kwang-Ho Oh, Won Hee Han, Jun-Ho Jang, Yong-Choo Tho, Hak Hyun Kim
Abstract Light weighting is a critical objective in the automotive industry to improve fuel efficiency. But when redesigning parts for light weight, by changing from metal to plastic, the resulting design gives NVH issues due to differences in part mass and material stiffness. Many parts were not converted from metal to plastic because of NVH issues that could not be solved. Many engine parts such as cylinder head cover, air intake manifold, oil pan and etc. previously made of metal have since long been replaced with plastic. But timing chain cover has not been replaced because of the aforementioned issue. Sealing performance due to the dynamic characteristics of the application is another challenging factor. In this paper, the key aspects of the plastic timing chain cover as well as its advantage are presented.
2014-04-01
Technical Paper
2014-01-1040
Gihwan Kim, Chi-Hoon Choi, You Sung Moon, Yong Sun (Steven) Jin
Abstract The main contribution of this paper is to employ a sound and vibration theory in order to develop a light and cost effective plastic intercooler pipe. The intercooler pipe was composed of two rubber hoses and one aluminum pipe mounted between an ACV (Air Control Valve) and an intercooler outlet. The engineering design concept is to incorporate low-vibration type bellows and an impedance-mismatched center pipe, which replaces the rubber hoses and aluminum pipe respectively. The bellows were designed to adapt powertrain movement for high vibration transmission loss to the intercooler outlet. Also, the impedance-mismatched center pipe was implemented to increase reflected wave by using relatively higher modulus than bellows part and applying a SeCo (Sequential Coextrusion) processing method.
2014-04-01
Technical Paper
2014-01-0011
Xiaozhen Sheng, Shouhui Huang, Sheng Tian, Xia Cao, Youlin Huang
Abstract Subject to excitations from pressure pulsations in boost air, the rubber pipe connecting the turbo compressor outlet and the intercooler of an engine vibrates structurally and radiates noise. If the pipe is improperly selected, the resulted vibration may be strong enough to radiate noise which is sufficient to damage the sound quality of the vehicle. This paper presents an initial analysis on this issue. First, formulae are derived for predicting vibration and sound radiation of the pipe for a given pressure pulsation, resulting in sound transmission index for the pipe to quantify its sound insulation behavior. Then effects on the sound transmission index are investigated for pipe parameters such as pipe wall thickness, Young's modulus and density of pipe material.
2014-04-01
Technical Paper
2014-01-0010
Hyungtae Kim, Sehwun Oh, Ki-Chang Kim, Ju Young Lee, Jungseok Cheong, Junmoo Her
Abstract It is common knowledge that body structure is an important factor of road noise performance. Thus, a high stiffness of body system is required, and determining their optimized stiffness and structure is necessary. Therefore, a method for improving body stiffness and validating the relationship between stiffness and road noise through CAE and experimental trials was tested. Furthermore, a guideline for optimizing body structure for road noise performance was suggested.
2014-04-01
Journal Article
2014-01-0008
Wei Yang, Wenku Shi, Chunxue Chen
Aiming at the abnormal vibration of driver seat of a passenger car in idle condition, vibration acceleration of engine, frame and seat rail was tested to identify vibration sources. Order tracking and spectrogram analysis indicated that the second order self-excitation of engine was the main cause. To solve the problem, semi-active controlled hydraulic engine mount with air spring of which characteristics could shift between a high dynamic stiffness and a low one was applied. Then the structure and principle of the mount with variable characteristics was introduced and control mode was analyzed. Dynamic characteristics were obtained by bench test. With sample mount applied, vibration of seat rail was tested again in multiple vehicle and engine working conditions. Dates showed that abnormal vibration in idle condition was extremely reduced and the mount could also meet the requirement of engine to dynamic stiffness in driving conditions.
2014-04-01
Journal Article
2014-01-0006
Tamer Elnady, Mats Abom, Yong Yang
Exhaust noise is a major contributor to the radiated noise level of a vehicle, especially at idle. The radiated noise level has to meet a certain criteria based on regulation and consumer demand. In many cases, the problem appears after the vehicle is manufactured and the tailpipe noise measurement is performed indicating a high noise level that needs to be reduced. This paper describes one of those cases where the radiated noise level of a certain passenger car at idle was required to be reduced by 6 dB(A). The exhaust system consists of one main muffler and one auxiliary muffler. A 1D two-port model of the exhaust system including the two mufflers was built using commercial software. This model was validated against the measurement of the two-port matrix of both mufflers. The model was then used together with tailpipe noise measurements to estimate the characteristics of the source strength and impedance.
2014-04-01
Technical Paper
2014-01-0005
Atul Devidas Pol, Praveen Naganoor
Abstract Achieving targeted global modes (torsion, vertical bending and lateral bending) is one of the main enablers in meeting desired NVH performance characteristics of a new vehicle program. The torsion mode of next generation Land Rover - Freelander was lagging behind its target while the development cycle was quite progressed beyond underbody freeze. There was a challenge to recover more than 8 Hz in BIW torsion mode. A combination of Nastran Sol 200 (design sensitivity and optimization) and iterative process was adopted to demonstrate how the mode could be recovered with optimum mass penalty to the program. The paper states the existing modal status when this work was taken up. Next it elucidates design sensitivity/optimization module outcome which identifies sensitive areas to improve torsion mode.
2014-04-01
Technical Paper
2014-01-0004
Ajo John Thomas, Avnish Gosain, Prashanth Balachandran
Abstract The automobile market is witnessing a different trend altogether - the trend of shifting preference from powerful to fuel efficient machines. Certain factors like growing prices of fuel, struggling global economy, environmental sensitiveness and affordability have pushed the focus on smaller, efficient and cleaner automobiles. To meet such requirements, the automobile manufacturers, are going stringent on vehicle weights. Using electric and hybrid power-plants are other options to meet higher fuel efficiency and emission requirements but significant cost of these technologies have kept their growth restricted to only few makers and to only few regions of the globe. Optimizing the vehicle weight is a more attractive option for makers as it promises lesser time to market, is low on investment and allows use of existing platforms.
Viewing 181 to 210 of 8700

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