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Viewing 1 to 30 of 11447
2018-01-16
Event
2017-09-19
Event
2017-06-05
Technical Paper
2017-01-1826
Sagar Deshmukh, Sandip Hazra
Engine mounting system maintains the position of power train in the vehicle with respect to chassis and other accessories during inertia, torque reaction loads and roadway disturbances. The mounting system also plays a role in terms of isolation of the rest of the vehicle and its occupants from power train and helps in maintaining vehicle ride and handling condition. This paper investigates the performance comparison between a conventional mount, hydromount and switchable hydromount during idle condition and ride performance. The optimization scheme aims to improve the performance of the mounting system in order to achieve overall power train performance and NVH attribute balancing through semi active technology. Keywords: Engine Mount, NVH,Switchable Hydromount
2017-06-05
Technical Paper
2017-01-1781
Joshua Wheeler
Automatic Speech Recognition (ASR) and Hands Free Communication (HFC) capabilities have become prominent in the automotive industry, with over 50% of new vehicle sales equipped with some level of ASR system. With the common use of mobile personal assistants and smartphones with Bluetooth capability, customer expectations for built in ASR and HFC systems have increased significantly. The performance of these ASR and HFC systems are highly dependent on the level of background or “masking” noise that competes with the speech engine’s ability to correctly convert the driver’s speech to actionable commands. HVAC noise provides high amplitudes of broadband frequency content that affects the signal to noise ratio (SNR) within the vehicle cabin, and works to mask the user’s speech. Furthermore, when the airflow from the panel or defroster vents are directed toward the vehicle microphone, a mechanical “buffeting” phenomenon occurs that distresses the ASR system even further.
2017-06-05
Technical Paper
2017-01-1766
Dirk von Werne, Stefano Orlando, Anneleen Van Gils, Thierry Olbrechts, Ivan Bosmans
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 to 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 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. This part is again based on analytical and empirical formulations.
2017-06-05
Technical Paper
2017-01-1847
Asif Basha Shaik Mohammad, Ravindran V, Nageshwara Rao P
The high noise and vibration levels, to which drivers of agricultural tractor are often exposed for long periods of time, have a significant part in the driver’s fatigue and may lead to substantial hearing impairment and health problems. For these reasons, the noise and vibration comfort has become an important criterion in the design of the driver’s cabin and a determining factor in the acceptance and sales potential of agricultural tractors. Therefore, it is essential for an optimal cabin design to have time and cost effective analysis tools for the assessment of the noise and vibration characteristics of various design alternatives at both the early design stages and the prototype testing phase. Airborne excitation and Structure Borne excitation are two types of dynamic cabin excitations mainly cause the interior noise in a driver’s cabin.
2017-06-05
Technical Paper
2017-01-1836
Fangfang Wang, Peter Johnson, Hugh Davies, Bronson Du
Introduction Whole-body vibration (WBV) is associated with several adverse health and safety outcomes including low-back pain and driver fatigue. Recently introduced active suspension truck seats have been shown to reduce WBV exposures up to 50% relative to industry standard air-suspension seats, but drivers do not universally prefer these active suspension seats and their higher costs concern some companies. The objective of this study was to evaluate the efficacy of three commercially-available air-suspension truck seats for reducing truck drivers’ exposures to WBV. Methods Seventeen truck drivers operating over a standardized route were recruited for this study and three commercially available air suspension seats were evaluated. The predominant, z-axis average weighted vibration (Aw) and Vibration Dose Values (VDV) were calculated and normalized to represent eight hours of truck operation.
2017-06-05
Technical Paper
2017-01-1858
James Haylett, Andrew Polte
Truck and construction seats offer a number of different challenges over automotive seats in the identification and characterization of Buzz, Squeak, and Rattle (BSR) noises. These seats typically have a separate air or mechanical suspension and usually have a larger number and variety of mechanical adjustments and isolators. Associated vibration excitation tend to have lower frequencies with larger amplitudes. In order to test these seats for both BSR and vibration isolation a low-noise shaker with the ability to test to low frequency, down to 1 Hz was used. Slowly swept sine excitation was particularly helpful in understanding the seat mode shapes and nonlinearities at low frequency which showed large displacements. A typical sample set of seat BSR sounds are described in terms their time and frequency characteristics and widely used sound quality metrics.
2017-06-05
Technical Paper
2017-01-1787
Jan Biermann, Adrien Mann, Barbara Neuhierl, Min-Suk Kim
Over the past decades, noise sources such as wind noise or engine noise have been significantly reduced leveraging improvements of both the overall vehicle designs and of sound packages. Consequently, noise sources originating from HVAC systems (Heat Ventilation and Air Conditioning), fans or exhaust systems are now becoming Tier-1 problems affecting quality and passenger comfort. Furthermore, existing experimental techniques are not adapted to internal flows and fail at identifying the location of noise sources, as well as corresponding design changes to reduce noise. This study focuses on HVAC systems and discusses a Flow-Induced Noise Detection Contributions (FIND Contributions) numerical method enabling the identification of the flow-induced noise sources inside HVAC systems. Moreover, this method provides the contribution of each source at the passenger’s ear locations considering the propagation of the noise through the system.
2017-06-05
Technical Paper
2017-01-1887
Antoine Minard, Christophe Lambourg, Patrick Boussard, Olivier Cheriaux
While electric and hybrid vehicles are becoming increasingly common, the issue of engine noise is becoming less important, because it does not dominate the overall noise perceived in the passenger compartment in such vehicles anymore. However, at the same time, other sound sources such as air conditioning, start to emerge, which can also cause annoyance. The CEVAS project, involving VALEO, CETIM, University of Technology of Compiègne, ESI GROUP and GENESIS, deals with the acoustic simulation and perception of automotive air-conditioning (HVAC) and electric battery cooling (BTM) systems. While the other partners focused their work on the aeroacoustic characterization, modeling and simulation, GENESIS’ part in the project is dedicated to HVAC sound synthesis and perception. In order to do the synthesis of the acoustic spectra provided by the partners of the project, an additive model was used.
2017-06-05
Technical Paper
2017-01-1861
Ismail Benhayoun, Frédéric Bonin, Antoine MILLIET de FAVERGES, Julien Masson lng
NVH (Noise Vibration & Harshness) is one of the main focus areas during the development of products such as passenger cars or trucks. Physical test methods have traditionally been used to assess NVH, but the necessity for reducing cost and creating a robust solution early on in the design process has driven the increased usage of simulation tools. Development of well-defined methods and tools for NVH analysis allows today's OEMs to have a Virtual Engineering based Development Cycle from Concept to Test. However, not all NVH problems have been focused on, including the issue of Squeak and Rattle (S&R). In a vehicle, S&R is a recurring problem for interior plastic parts such as an Instrument Panel or Door Trim. Since 2012, Altair has been developing S&R Director (SnRD), which is a solution that identifies and combats S&R issues by embedding E-Line methodology [1] [2]. This methodology is based on Industry Best Practices, as described in the paper SAE 2012-01-1553.
2017-05-08 ...
  • May 8-9, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Heat transfer affects the performance, emissions and durability of the engine as well as the design, packaging, material choice and fatigue life of vehicle components. This course covers the broad range of heat transfer considerations that arise during the design and development of the engine and the vehicle with a primary focus on computational models and experimental validation covering the flow of heat from its origin in the engine cylinders and its transfer via multiple paths through engine components.
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