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2014-11-12
Article
A Level 2 electric vehicle charger that can dispense power based on the available grid supply is undergoing its first field test in Detroit.
2014-11-11
Technical Paper
2014-32-0026
Alessandro Franceschini, Emanuele Pellegrini, Raffaele Squarcini
Abstract Nowadays the challenge in design of auxiliary devices for automotive small engines is focused on packaging reduction and on the increase of the performance. These requirements are in contrast to each other and in order to fulfil the project specifications, new and more refined design tools and procedures need to be developed. This paper presents a calculation loop developed by Pierburg Pump Technology Italy S.p.A. (PPT). It supports the design of a variable displacement oil pump component for engine applications. The work is focused on the fatigue life evaluation of a joint, which transmits the drive torque from the engine to the oil pump. The aim of the procedure is to calculate the onset of the surface fatigue phenomenon in the hexagonal joint which drives the oil pump, taking into account the axes misalignment and the flat-to-flat clearance. The study has involved several matters, experimental measures, CFD, MBA and FEM analyses.
2014-11-11
Technical Paper
2014-32-0063
Daniela Siano, Fabio Bozza, Danilo D'Agostino, Maria Antonietta Panza
Abstract In the present work, an Auto Regressive Moving Average (ARMA) model and a Discrete Wavelet Transform (DWT) are applied on vibrational signals, acquired by an accelerometer placed on the cylinder block of a Spark Ignition (SI) engine, for knock detection purposes. To the aim of tuning such procedures, the same analysis has been carried out by using the traditional MAPO (Maximum Amplitude of Pressure Oscillations) index and an Inverse Kinetic Model (IKM), both applied on the in-cylinder pressure signals. Vibrational and in-cylinder pressure signals have been collected on a four cylinder, four stroke engine, for different engine speeds, load conditions and spark advances. The results of the two vibrational based methods are compared and in depth discussed to the aim of highlighting the pros and cons of each methodology.
2014-11-11
Technical Paper
2014-32-0061
Rama Subbu, Baskar Anthony Samy, Piyush Mani Sharma, Prasanna Mahendiran
Abstract Ride comfort, driving stability and drivability are vital factors in terms of vehicle performance and customer satisfaction. Crankshaft unbalance is a source for the vibration that reduces the vehicle performance and it needs to be controlled to some extent such that the vehicle performance will be improved. The IC engine is made up of reciprocating and rotating parts. They produce unbalance forces during their operation and produces vibration in Vehicle. The vibration reduction will be possible by minimizing these unbalance forces and by optimizing the crankshaft of the two wheeled vehicle engine design. Many researches were made to find the causes for the vibration and to reduce it. But still there is a research gap on the testing and simulation of engine components (crankshaft, connecting rod and piston assembly). In this study, an attempt is made to represent the engine vibrations and its isolation to provide a gate way for the future work on it.
2014-11-11
Technical Paper
2014-32-0047
Mohamed El Morsy, Gabriela Achtenova
Abstract Using the PULSE platform for vibration analysis, which has been developed as an advanced solution for vibration measurements, the Robust Diagnostic Concept (RDC) was elaborated. The PULSE setup is designed to aid in fault diagnosis of a vehicle gearbox - the main part of a vehicle powertrain. Time Domain, Continuous Wavelet Transformation Technique (CWT), FFT and order analysis measurements are used for detection of an artificial pitting defect in a gear by tracking the gearbox response at accelerated speed and different loads. The test stand is equipped with three dynamometers; the input dynamometer serves as the internal combustion engine, the output dynamometers introduce the load on the flanges of the output joint shafts. The pitting defect is manufactured on the tooth side of the fifth speed gear on the intermediate shaft. The effect of temperature on the vibration measurements was also investigated to study its impact on the fault diagnosis.
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.
2014-11-11
Technical Paper
2014-32-0123
Vishnu Kumar Kuduva Shanthulal, Kannan Marudachalam, V Pattabiraman, S Jabez Dhinagar, Chandramouli Padmanabhan
Abstract The diesel power train (engine and transmission) is the most significant mass contributor in a three- wheeled vehicle. High idling vibrations from the engine get transmitted to the structure and the body panels through the engine mounts. Isolation of these vibrations by proper design of rubber mounts is the most effective engineering approach to improve ride quality of vehicle. In the present study, a mathematical model of the powertrain and mount system is developed; with the engine and transmission being assumed to behave as a rigid body (6 degrees-of-freedom) and the compliance comes from the mounts. As a first step, the modes and natural frequencies are obtained. Following this the response to unbalanced inertial forces for an excitation frequency range of 20-60 Hz (1200-3600 rpm) has been obtained. The model is validated by comparing its results with results of previous published research work.
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.
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.
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.
2014-11-11
Journal Article
2014-32-0053
Yoshihiro Nakagawa, Shinya Takahashi, Mikihito Masaki, Ranju Imao
Abstract In brake squeal analyses using FE models, minimizing the discrepancies in vibration characteristics between the measurement and the simulation is a key issue for improving its reproducibility. The discrepancies are generally adjusted by the shape parameters and/or material properties applied to the model. However, the discrepancy cannot be easily adjusted, especially, for the vibration characteristic of the disc model of a motorcycle. One of the factors that give a large impact on this discrepancy is a thermal history of the disc. That thermal history includes the one experienced in manufacturing process. In this paper, we examine the effects of residual stress on the natural frequency of motorcycle discs. The residual stress on the disc surface was measured by X-ray stress measurement method. It was followed by an eigenvalue analysis. In this analysis, we developed a unique method in which the residual stress was substituted by thermal stress.
2014-11-11
Journal Article
2014-32-0018
Kenichi Morimoto, Kenichi Tanaka
Abstract There have been a number of attempts to clarify the relationship between motorcycle specifications and shimmy phenomenon. Some of such efforts are based on equations of motion. The methods used in those efforts are suitable for analyzing motions in a fundamental structure. However, when the degree of freedom is large, it is extremely difficult to deliver an equation of motion. Therefore, a practical method cannot be found generally when applying the methods employing equations of motion. We also conducted the analysis of shimmy using multi-body dynamics simulation. The yielded results were useful only for clarifying the differences in shimmy levels among motorcycles. However, they were not helpful to understand the relationships between specifications and shimmy phenomenon.
2014-11-11
Journal Article
2014-32-0059
Antonio Agresta, Francesca Di Puccio, Paola Forte, Gabriele Benigni
Abstract NVH simulations for an automotive component industry represent a convenient mean to compare different solutions and make decisions on design choices based on the predictions of the component vibro-acoustic behavior. This paper presents the vibro-acoustic characterization and comparison of two fuel rail assemblies (FRAs) by mean of simulations in Ansys Workbench & LMS Virtual.Lab. These simulations required a preliminary finite element (FE) modal analysis on the FRAs. To verify the reliability of the FE models, an experimental modal analysis was performed on one of the two fuel rails in free-free condition. The correlation between FE and test models highlighted some differences: a sensitivity study proved that the differences depend on the modeling of some brazed joints. The results of the following NVH simulations were checked by performing an acoustic impact test on the two FRAs in free-free condition inside an anechoic chamber.
2014-11-11
Journal Article
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.
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.
2014-11-04
Technical Paper
2014-36-0762
Gabriela Virginia Santiago
Abstract The modern approach that divides art and science ignores that they both have in common the pursuit of knowledge. The work of great artists and thinkers of all times has been influenced by the study of physical phenomena perception, on the ground that to achieve a more accurate comprehension of an aesthetic event, it is necessary to go beyond the receiving subject and ponder on the artist too. When a stimulus is perceived through the senses, a reconstruction takes place in the consciousness that allows its perception as a coherent wholeness; an acoustic stimulation generates a sensation that reveals the aesthetic sense and sets aside objective registers to give way to the symbolism of sound. The reasoning and logical rigor of acoustics as an exact science finds a connection point with pure expression that includes technology as a fruitful field of art.
2014-11-04
Technical Paper
2014-36-0766
Clodoaldo Borges Chagas, Thiago Caetano de Freitas, Robson Pederiva
Abstract More and more, the automotive vehicle consumers tend to opt for internal combustion engines which use chain in their timing system, since the chain drive system presents high durability, avoiding the usual maintenance common to the belt timing system. The necessity of developing parts which increase the fuel consumption efficiency and minimize noise and vibration leads to the study and comprehension of some physical phenomena such as “polygonal action” and the ability of predicting the fluctuation of angular velocity of the sprockets used for timing the crankshaft and camshaft. The study of mathematic models in parallel to the physical test guides the development of the present work.
2014-11-04
Technical Paper
2014-36-0767
Carlos Augusto Garcez da Silva, Márcio Calçada, Luiz Cesar Massarelli
Abstract It is known acoustic comfort is a key feature to meet customer expectations for many products. In the current automotive industry, vehicle interior quietness is seen as one of the most important product attributes regarding perceived quality. A quiet interior can be achieved through an appropriate balance of noise sources levels and acoustic materials. However, the choice of the most efficient acoustic content may be challenging under severe cost and mass restraints commonly found in emerging market vehicles. Therefore, it is fundamental to develop efficient materials which will provide high acoustic performance with lower weight and cost. In this paper the fine tuning of the headliner structure is presented as an efficient way to increase acoustic performance. Structures currently employed for this vehicle subsystem are described. Airflow resistance and sound absorption measurements are used to guide development and make precise manufacturing process changes.
2014-11-04
Technical Paper
2014-36-0768
Alexis Klauber Chaia Kléperon, Robson Demétrius Araújo Abreu, Rômulo Morais Bitencourt, Francis José Marochi Almeida
Abstract The vibroacoustic comfort sense inside vehicles is a topic of major concern in current automotive industry. Moreover, the increase in demand of users and the competition in the automotive sector lead automakers to invest in developing more comfortable vehicles. Thus, even noises in specific usage scenarios and short time is claimed. This paper raises the cause and proposes solutions to a noise from the brake system known as “Moan Noise”. This noise happens under specific conditions of use, but is easily identified by the user. Moreover, it is a random phenomenon and difficult to characterize. Thus, this study shows a methodology to survey the phenomenon under study and validation of proposals for improvement through operational techniques and experimental modal analysis.
2014-11-04
Technical Paper
2014-36-0773
Rodrigo Santos, João Paulo Sabioni, César Abrahão, Alexandre Ramos
Abstract Air conditioning systems are being increasingly applied in the Brazilian automotive industry becoming indispensable rather than an optional item for car buyers, who are constantly seeking out more comfort. Conversely, the application of these systems in motor vehicles involve the use of compressors which operate at high pressures, making them important sources of vibration and unwanted noise in the cabin of the vehicle, thus causing vibratory discomfort and noise annoyance. Despite the major technological developments in automotive air conditioning systems, there is still a shortage of engineering research conducted in the field of vibration and noise originated in these particular systems. The present study is aimed at investigating and characterizing experimentally the vibration and acoustic propagation in the interior of a vehicle, generated by the compressor of the air conditioning system.
2014-11-04
Technical Paper
2014-36-0782
K. F Lima, V. Pimental, N. Barbieri, R. Barbieri, A. A. M. Campos
Abstract Currently, the Brazilian fleet is estimated at 40.0 million automotive vehicles. In the urban centers, as a consequence of this fact, the humans are being exposed daily to continuous and intermittent unwanted noises emitted by these vehicles. The prolonged exposure to noise can cause irreversible damage to human health. As a general rule, the automotive noises are low frequency and the mufflers used to attenuate these noises are made by uniting several kinds of acoustic filters. There are two types of acoustic filters: reactive and dissipative. The first type is made by the expansion chambers, resonators, labyrinths, perforated tubes and other types, by the addition of absorbent material to its inner part. The absorbent materials are fibrous and they have the purpose of increasing the efficiency of acoustic filters. The mufflers built with these two types of filters are called hybrids. There are many works that involve purely reactive mufflers without absorbent material.
2014-11-04
Technical Paper
2014-36-0785
Augusto Amador Medeiros, Zargos Neves Masson, Pablo Giordani, Julio Cordioli
Abstract With the increase in aircraft transportation and, consequently, aircraft noise in the last decades, measurement of acoustic liner impedance under grazing flow has become a point of interest. Different indirect methodologies have been developed by independent research groups to solve this problem. The Mode-Matching technique and, more recently, the Two-Port method are examples of developed methodologies that use acoustic pressure measurements in a test rig where a liner sample is subject to grazing mean flow to educe its impedance. In this paper, both methods are explained, implemented and used to educe the acoustic impedance of different liner samples in a recently developed grazing flow impedance eduction test rig. Additionally, both methods are compared based on their computational cost and limitations.
2014-11-04
Technical Paper
2014-36-0789
Oscar Acosta, Augusto Medeiros, André Spillere, Julio A. Cordioli, Danillo Reis
Abstract This article presents a comparative analysis of the influence of different types of flows over fan noise propagation and scattering within the nacelle intake of aircraft turbofan engines. The methodology for the noise simulation is explained. First, the fan noise source is modeled using a boundary condition that represents all the uncorrelated cut-on modes in the interior of the nacelle duct. Then different types of flows and flight conditions are considered in order to determine the influence of the aerodynamic phenomenon in the noise emitted by the nacelle intake. The liner attenuation is also simulated by mean of Myers boundary condition. Finally the results for far field noise are validated against numerical data obtained from the literature for hard and lined wall conditions.
2014-11-04
Technical Paper
2014-36-0794
Frederico Luiz de Carvalho Moura, Celso Kenzo Takemori, Edmar Baars, Suelen Ribeiro
Abstract Currently the numerical simulations of the vibro-acoustic behavior of vehicles are built considering only major structures, such as its basic structure (body in white), doors, dashboard etc. To take into account the contribution of other components (such as trims, seats, sound insulation etc.) to the overall response of the model, the average characteristics of these materials are inserted globally in this model. However, for more correlated models is necessary to consider local characteristics of these components. This work presents the numerical procedure for simulating the effect of the structural damping of viscoelastic coatings and the acoustic absorption of the trims such that its effects can be considered in the model of the full vehicle. The operating forces applied to the model were estimated from the laboratory and road tests using the SPC/TPA technique.
2014-11-04
Technical Paper
2014-36-0791
Mauricio Massarotti, Yuri Ribeiro, Márcio Calçada
Abstract Microphone array based techniques have a growing range of applications in the vehicle development process. This paper evaluates the use of Spherical Beamforming (SB) to investigate the transmission of wind-generated noise into the passenger cabin, as one of the alternative ways to perform in-vehicle troubleshooting and design optimization. On track measurements at dominant wind noise conditions are taken with the spherical microphone array positioned at the front passenger head location. Experimental diligence and careful processing necessary to enable concise conclusions are briefly described. The application of Spherical Harmonics Angularly Resolved Pressure (SHARP) and the Filter-And-Sum (FAS) algorithms is compared. Data analysis variables, run-to-run repeatability and system capability to identify design modifications are studied.
2014-11-04
Technical Paper
2014-36-0793
Elton J. Zanol, Letícia Fleck Fadel Miguel, Tiago Becker
Abstract Bus drivers are daily exposed to whole-body vibrations (WBV) submitted to risks for develop health problems related to these conditions. Numerous studies focused to quantify and identify the risks that drivers are exposed have been developed in recent years. Many factors influence the transmission of vibration to the body. Road type may be an important factor in determining the WBV exposure a bus driver receives. In urban areas, common types of routes include several road surfaces like: smooth highway, older rough freeway, pavement, bumpy, speed humps, and others. The purpose of this study was to determine whether different kinds of road surfaces, found in urban routes, cause different WBV responses, and determine the influence for each road type in daily exposure to WBV according the standard ISO 2631-1 (1997).
2014-11-04
Technical Paper
2014-36-0798
Farokh Kavarana, John DeYoung, Hiroyuki Nakajima
Abstract The fuel economy benefits of Continuously Variable Transmission (CVT) technology have led to a steady growth in their adoption since the 1990's that is likely to continue despite the competition from Dual Clutch Transmission (DCT) & Automated Manual Transmission (AMT) technology. Even though CVTs provide a smoother driving experience due to their “shift-free” operation, general market feedback indicates some level of consumer dissatisfaction in the area of acceleration sound quality. This is particularly evident in the sub-compact and compact vehicle segments that feature small four cylinder engines with cost/weight limited sound packaging. The dissatisfaction with the acceleration sound quality is primarily linked to the non-linear relationship between engine RPM and vehicle speed that is inherent to CVTs and is often referred to as “rubber-band” feel.
2014-11-04
Technical Paper
2014-36-0796
Frederico Luiz de Carvalho Moura, Tiago Simão Ferreira, Rogério Gondim Costa, Celso Kenzo Takemori, Edmar Baars
Abstract Currently, the simulation models in acoustics and vibrations are built considering only the main structures of the vehicle, as its basic structure (Body-in-white, BIW), doors, dashboard, and so on. To take into account the contribution of components with less influence (such as carpets, seats, sound insulation, and so on) in the behavior of the overall response of the model, the average characteristics of these materials are inserted evenly distributed in these models. However, to obtain models with better correlation levels is necessary to consider local characteristics of the application of these components. In this work was developed and numerically validated, the model that describes the standardized test of “Oberst Beam” (ASTM E 756-98) to obtain the damping of the blankets used for damping of the panel vibration. With these characteristics, in future work, is expected to be possible, also with a good correlation, consider the effect of these materials on whole vehicle.
2014-11-04
Technical Paper
2014-36-0801
Herman Van der Auweraer, Fabio Bianciardi, Patrick Van de Ponseele, Karl Janssens
Abstract The Transfer Path Analysis method is at the core of the Source-Transfer-Receiver approach to address noise and vibration problems. While originally developed for analyzing structure-borne noise transmission, its application range has been extended to airborne noise. Various frequency and time domain approaches have been developed with a focus of supporting specific design engineering problems. One such application is the source contribution analysis in the context of vehicle pass-by-noise. The upcoming changes in the pass-by noise regulation will not only require more complex tests in different conditions but most importantly, the new directive will force car manufacturers to further reduce the emitted noise levels of their vehicles.
2014-11-04
Technical Paper
2014-36-0799
Steven Dom, Theo Geluk, Karl Janssens, Herman Van der Auweraer
Abstract The source-transfer-receiver model to approach automotive NVH problems has proven its worth over the last decades. The approach allows splitting up an NVH problem into a source, for example engine vibration or road induced wheel vibration, a transfer system, for example the car body or car suspension, and a receiver such as the driver ear or steering wheel feeling. The analysis of such a system is called Transfer Path Analysis (TPA). Whereas the determination of the transfer system for a TPA analysis through frequency transfer functions or a set of modes is fairly straightforward, the source side can pose quite some difficulties. For the sake of this paper, the sources are defined as the forces acting on the body structure of a car through the engine (for an engine noise problem) or suspension mounts (for a road noise problem).
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