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2015-03-30
Technical Paper
2015-01-0107
Sunny Narayan
Abstract Analysis of noise level from engines is important from point of view of customer satisfaction. Accurate prediction of noise is important for planning, design and target setting decisions for meeting customer satisfaction goals. In this work an analytic model has been described to break diesel engine noise data into various components in order to plan a strategy for condition monitoring of engine.
2015-03-30
Technical Paper
2015-01-0106
Zhe Yu, Wenjie Qin, Qingdong Hou, Mu Tang, Yang Ran
Abstract Wiper noise generated in the wiping process is one of the main influence factors affecting the driving comfort. Since the dynamic contact pressure of the contact between a blade and a windshield glass is difficult to be measured, it is also difficult to predict the degree of the wiper noise. In this paper, in the view of the reversal noise problem of a passenger-vehicle windscreen wiper system, the system dynamic models of the both wipers on the sides of the driver and copilot were built as considering the blade deformation and the elastic contact between the blades and the windscreen glass, including the crank pivot, the four linkage mechanism, the wiper blades, the wiper arms and the windscreen glass. The motion of the wiper system and the pressure distributions between the blades and the windscreen glass were analyzed under the half-dry condition.
2015-03-24
Article
In the area of electronics enclosures, traditional metal structures conduct and spread heat over large surfaces, but composites act as insulation. Heat generated by components causes internal temperatures to rise and has detrimental impact on the performance and reliability of the electronics.
2015-03-24
Article
Instron offers the AVE 2 second-generation advanced video extensometer non-contacting strain measurement device.
2015-03-18
Article
Keysight Technologies has enhanced its B1505A power-device analyzer/curve tracer, allowing it to characterize all key parameters of on-wafer and packaged devices for semiconductor development.
2015-03-10
Technical Paper
2015-01-0012
Mohammad Fard, Zhengqing Liu
Abstract The development and application of the vehicle advanced CAE (computer aided engineering) allowed the vehicle designers to considerably reduce the weight and improve the structural performance of the body. However, the current advanced CAE model can only be available in the late design phase of the vehicle when only minor changes of the structure is feasible. Despite the detailed CAE model, which requires all detailed design, the concept CAE model can be created with less need for the detailed CAD data and it can be created in the early (concept) design phase. The members and panels of the automotive body in white (BIW) are modeled and approximated using beam and shell elements. The joints properties are then obtained from the original detailed CAE model using Guyan reduction method. The automotive seat concept model is also created and added to the concept BIW model.
2015-03-10
Technical Paper
2015-01-0020
Kijong Park, Hongsuk Suh, Bonggyu Son
Abstract Shift feeling is one of the most important factors in developing a manual transmission. When drivers operate a manual transmission vehicle, they experience shift feeling which is classified into several factors such as shift smoothness, clarity, comfortability, sportiness, and so on. In the factors, shift smoothness characterized by double bump force is regarded as one of the most important things in experiencing shift feeling in Europe. The double bump force is reduced by attaching a constant mass damper which creates larger inertia of shift lever in control system of manual transmissions. However, it is possible to have side effects such as vibration of shift lever and clonk noise when employing the constant mass damper. In this research, a new control system with a variable inertia mechanism is designed and investigated to improve shift feeling while minimizing the side effects.
2015-03-10
Technical Paper
2015-01-0043
Rong Guo, Chong Cao, Yi Mi
Abstract From traditional vehicle to pure electric vehicle and then to range-extended electric vehicle (ReEV), the electrification of vehicle has caused a great change in NVH characteristics. ReEV has the most complex noise and vibration problems because it behaves both like traditional vehicle and pure electric vehicle. In addition, it has its own specific NVH characteristics. Firstly, internal combustion engine drives the generator rather than drives the vehicle. Due to the structure and load change, auxiliary power unit (APU) performs specific NVH characteristics. In addition, the pure electric mode will have the high frequency noise generated from the driveline because the noise couldn't be masked by the engine. In system level, unexpected and confusing sound in passenger compartment may affect the driver's comfort and judgments. Therefore, more and more attentions on these issues should be paid. NVH study and improvement methods on ReEV are emphasized.
2015-03-10
Technical Paper
2015-01-0040
Rong Guo, Chong Cao, Yi Mi
Abstract In course of the electrification of vehicle's powertrain, one of the vital problems we've been faced with is the limitation of the vehicle's driving range due to the capacity of currently available batteries. Therefore, range-extended electric vehicle (ReEV) concept has become one of the most promising transitory technologies to compensate this defect. Electric vehicle is supposed to be quiet and comfortable for the customers. However, some annoying sound derived from powertrain and accessories must be reduced or eliminated to meet this requirement. Accessory NVH has an important contribution to ReEV's NVH performance. If it is not well handled, poor vibration and noise may appear. This paper focuses on accessories' NVH performance in ReEV including the NVH problems from steering pump, vacuum pump and AC compressor.
2015-03-10
Technical Paper
2015-01-0046
Zhengqing Liu, Mohammad Fard, Reza Jazar
Abstract Characterizing the acoustic properties of sound-absorbing materials is costly and time consuming. The acoustic material database helps the automotive designers design their interior trims in accordance with target level for interior noise. In this paper, a two-microphone impedance tube was used to measure the normal sound absorption coefficient. The main parameters that are used in the theoretical model for interior noise level assessment are investigated. These parameters include thickness, airflow resistivity, porosity, tortuosity, viscous and thermal characteristics length. The measured results have been validated by the theoretical models. The validation of normal sound absorption coefficient was found to be in agreement with its corresponding measurement data. Finally, the sensitivity of the sound absorption coefficient which is related to the physical properties mentioned above is further analyzed.
2015-03-10
Technical Paper
2015-01-0047
Rong Guo, Yi Mi, Chong Cao
Abstract In recent years, electric vehicle and hybrid vehicle are either on the market or under intensive research and development (R&D). Since the concept of auxiliary power unit (APU) was brought into the automotive industry, the range-extended electric vehicle (ReEV) has become the favor of the worldwide manufacturers. Normally, the APU starts and stops more frequently in response to the control strategy compared with traditional vehicles, which will affect the ride comfort of passengers. Thus, APU start-stop NVH refinement is an important aspect of ReEV R&D. In this paper, a subjective evaluation on a ReEV was performed to quickly diagnose NVH issues firstly. Based on subjective results, the NVH experiment in a semi-anechoic room was carried out to troubleshoot these issues. The accelerations of the APU mounts, the seat track and the steering wheel as well as interior noise level were acquired and analyzed.
2015-03-05
Article
Applus IDIADA listened to customer feedback in developing its new DynaWheel-III device, focusing on making the system even more reliable and easy-to-use. The wheel position measurement system is composed of two separate parts: the mechanical arms with six absolute optical encoders and the new electronic box (DW-Box), providing real-time calculation of wheel position.
2015-03-03
Article
dSPACE has launched a new, compact control system development platform for laboratory use, MicroLabBox, that offers high computing power and comprehensive functionalities.
2015-03-03
Article
To sharpen a significant aspect of its marque identity, a tunnel is at the heart of company’s new €4.5 million Lighting Assistance Center (LAC) at its Ingolstadt, Germany, headquarters is helping it develop new technologies including matrix laser forward lighting.
2015-02-25
Article
Delcam’s 2015 version of its PowerINSPECT inspection system includes automatic collision avoidance, faster import of large CAD files, quicker preparation of longer inspection reports, and improved display of results from point-cloud data, plus many other customer-requested enhancements.
2015-02-23
WIP Standard
J2567
This SAE Recommended Practice establishes the test procedure, environment and instrumentation for determining the sound levels of snowmobiles in the stationary test mode. This test method is intended to provide an accurate measurement of exhaust and other engine noise and may be used to evaluate new and in-use snowmobiles to determine compliance with noise control regulations. Sound level measurements obtained with this test method are not intended as an engineering determination of overall machine noise. For this purpose, the use of SAE J192 is recommended.
2015-02-19
Article
Conventional CT scanners cannot accommodate long or bulky aircraft components.
2015-02-12
Article
NASA has expanded its use of Exa's PowerFLOW software for the simulation of concepts to reduce aircraft noise within NASA's Environmentally Responsible Aviation project.
2015-02-11
Article
At the McKinley Climatic Laboratory at Eglin AFB, an F-35 will ultimately be tested in all the meteorological conditions representative of those locations from which it will operate, ranging from the heat of northern Australia to the bitter cold of the Arctic Circle.
2015-02-06
Magazine
Rotary SI/CI combustion engines: A thing of the future? The internal combustion engine enjoys widespread use as an inexpensive and reliable power conversion system. While piston engines date back 150 years, various alternative engine architectures and cycles have been considered. Aftertreatment comes with challenging diagnosis Diagnosing engine and aftertreatment systems is forcing design teams to look at new ways to diagnose problems over long vehicle lifetimes. Taking on NVH reduction techniques A look at the enhanced durability benefits obtained by changing the polymer composition, manufacturing methods, and design optimization of a powertrain mount for an off-highway vehicle.
2015-02-03
Article
LaVision’s internal combustion optical sensor product family provides a series of techniques for the measurement of quantitative, in-cylinder, engine-relevant values.
2015-02-03
Article
Intertek recently acquired an ETS Solutions vibration and mechanical shock system that will enable the company to double its existing capacity on high payload testing.
2015-01-14
Technical Paper
2015-26-0125
Sambhaji Keshaw Jaybhay, Sudhakara Naidu, Prasanna Nagarhalli, J Saiprasad
Abstract This paper discusses various fruitful iterations / experiments performed to reduce air flow induced noise without compromising on total air flow requirement for thermal comfort and ways to avoid heat ingress inside the bus. Also the paper discusses the devised process for noise reduction through front loading of computer aided engineering and computational fluid dynamics analysis. Air conditioning buses in light commercial vehicle (LCV) segment is growing market in India, especially for applications like staff pick-up and drop, school applications and private fleet owners. The air-conditioning system is typically mounted on bus roof top and located laterally and longitudinally at center. It is an easiest and most feasible way to package air conditioning system to cater the large passenger space (32 to 40 seats) with the conditioned air. This makes air conditioning duct design simple and commercially viable.
2015-01-14
Technical Paper
2015-26-0123
Yogesh Surkutwar, Mahesh Anand Patwardhan, Nagesh Voderahobli Karanth, Atul Gaikwad
Abstract The work presented in this paper deals with the use of combined Computer Aided Engineering (CAE) and experimental testing approach for reducing engine noise. The paper describes a systematic approach for giving solutions to the structure borne engine noise related problems. Noise Source Identification (NSI) was carried out on diesel engine to identify noise radiating sources, ranking of noise sources was carried out and contribution of individual engine component in radiated Sound Power Level (SWL) was computed. Detailed Finite Element Model (FEM) of engine assembly was developed and model was correlated in terms of natural frequencies and transfer functions by performing modal testing. Correlated FEM was used for predicting surface vibration velocities under various engine speeds and loading conditions in frequency domain. Velocities so predicted in frequency domain were used as an input for SWL prediction using Boundary Element Method (BEM) approach.
2015-01-14
Technical Paper
2015-26-0122
Herman Van der Auweraer, Karl Janssens, Fabio Bianciardi, Filip Deblauwe, Kumaraswamy Shivashankaraiah
Abstract Certification of vehicle noise emissions for passenger vehicles, motorcycles and light trucks is achieved by measuring external sound levels according to procedures defined by international standards such as ISO362. The current procedure based on a pass-by test during wide-open throttle acceleration is believed far from actual urban traffic conditions. Hence a new standard pass-by noise certification is being evaluated for implementation. It will put testing departments through their paces with requirements for additional testing under multiple ‘real world’ conditions. The new standard, together with the fact that most governments are imposing lower noise emission levels, make that most of the current models do not meet the new levels which will be imposed in the future. Therefor automotive manufacturers are looking for new tools which are giving them a better insight in the Pass-by Noise contributors.
2015-01-14
Technical Paper
2015-26-0129
Kapil Gupta, MR Vikram, Eugenio Manta
Abstract A turbocharger unit mainly consists of a centrifugal compressor and a turbine coupled together by a solid shaft. This is employed to boost the charge air pressure of the engine. Turbocharging in modern diesel and gasoline engines have become a common and essential operation to result higher power outputs, lower emissions, improved efficiency and refinements from a similar capacity of naturally aspirated engines. The automotive turbocharger system is a source of synchronous and asynchronous noises that should be eliminated or reduced for passenger comfort. Subjectively, a high whistle noise was audible in the passenger cabin during in a mid-rpm range drive in all gears in a 4 cylinder diesel vehicle. Objective noise and vibration data confirm the issue as unbalance whistle. A detailed study has been carried out to identify the source and radiating part of the unbalance whistle noise generated in a 4 cylinder diesel engine running a passenger car.
2015-01-14
Technical Paper
2015-26-0127
Gaurav Paliwal, Naveen Sukumar, Umashanker Gupta, Saurav Roy, Hemantkumar Rathi
Abstract The main emphasis for a commercial vehicle design which was focused on fuel-economy and durability does not fulfill the increasing customer expectations anymore. Commercial vehicle designers need to focus on other vehicle aspects such as steering, ride comfort, NVH, braking, ergonomics and aesthetics in order to provide car like perception to truck, bus drivers and passengers during long distance drives. Powertrain mounting system must perform many functions. First and foremost, the mounting system must maintain & control the overall motion of the powertrain, to restrict its envelope reasonably, thereby avoiding damage to any vehicle component from the potential impact. This requires the mount to be stiff. Second the mount must provide good vibration isolation to have a comfortable ride to the vehicle occupant. This requires the mount to be soft.
2015-01-14
Technical Paper
2015-26-0140
Milind Ambardekar, Adatiya Yogesh, Sudhakara Naidu
Abstract Production variations of a heavy duty truck for its vibrations were measured and then analyzed through an Ishikawa diagram. Noise and Control factors of the truck idle shake were indentified. The major cause was found to be piece to piece variations of its power-train (PT) rubber mounts. To overcome the same, a new nominal level of the mount stiffness was sought based on minimization of a cost function related to vibration transmissibility and fatigue damage of the mounts under dynamic loadings. Physical prototypes of such mounts were proved to minimize the variations of the driver's seat shake at idling among various trucks of the same design. These learning's are useful for design of various subsystems or components to refine the full vehicle-Noise Vibration Harshness (NVH) at the robust design level.
2015-01-14
Technical Paper
2015-26-0146
Dhanashri Ravikiran Desai, Suhas Suryawanshi, Bhalchandra Deshmukh
Abstract Developing countries like India is now highly relying on the alternate source of power generation to have uninterrupted power supply for their economic development. Diesel Power generator is one of the solutions in meeting the uninterrupted power requirement. In India, Power generating sets are having stringent emission norms and also the present government policies of removing subsides from Diesel fuel adding the additional burden on operating cost. As such researcher has a tough task to design the product considering the stringent requirement of legislation and performance. The main focus of this research work is to address performance necessities and the noise legislation. The detail methodology has been laid down to analyze and optimize performance and noise of Diesel Generator with respect to cooling system. Cooling fan with drive arrangement has been selected to study the canopied Diesel Generator performance and overall noise emission.
2015-01-14
Technical Paper
2015-26-0134
Jayant Sinha, Ajit Kharade, Shrihari Matsagar
Abstract An interior sound quality is one of the major performance attribute, as consumer envisage this as class and luxury of the vehicle. With increasing demand of quietness inside the cabin, car manufactures started focusing on noise refinement and source separation. This demand enforces hydraulic power steering pump to reduce noise like Moan and Whine, especially in silent gasoline engine. To meet these requirements, extensive testing and in-depth analysis of noise data is performed. Structured process is established to isolate noises and feasible solutions are provided considering following analysis. a) Overall airborne noise measurement at driver ear level (DEL) inside the cabin using vehicle interior microphone.b) Airborne and Pressure pulsation test by sweeping pump speed and pressure at test bench.c) Waterfall analysis of pump at hemi anechoic chamber for order tracking and noise determination.
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