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2017-03-28
Technical Paper
2017-01-1050
George Nerubenko, Cyril Nerubenko
The study of dynamical performance and effectiveness of new proposed system of vibration dampers for any type of propulsion (Electric Motor Cars, Hybrid Vehicles and Petrol Engine Automobiles) is presented. Design and structure of proposed system is based on George Nerubenko US Patents 7,438,165 and 7,464,800 having the control system with self-tuning contour adjusted for all operational frequencies in running propulsion. The proposed system of vibration damper configurations having the simplest mechanical variable damping devices is observed. The proposed system of vibration dampers consists of combination of patented Bending / Torsional Vibration Dampers and Flywheels. The developed schemes would be applied for a design of all kinds of powertrains, transmissions, and drivelines successfully replacing the conventional vibration reduction tools.
2017-03-28
Technical Paper
2017-01-1072
Jelena Andric
Variable valve actuation (VVA) plays a promising role in supporting advanced combustion methods to meet increasingly stringent fuel efficiency and emission standards in modern vehicles. Much research has been done on VVA to exploit its potential for increasing the overall engine performance. Consequently, the use of VVA in internal combustion engines (ICE) has become more prevalent in recent past. Different flexible VVA technologies have been designed and manufactured to make it possible to control valve events and valve timing over the entire operating range of an engine. Therefore, it is of high interest to comprehensively understand the benefits of numerous VVA mechanisms that can be used to ensure the flexibility of the valve train system. Variable valve timing (VVT) technologies include early or late opening or closing time of the intake or exhaust valves. VVA combine any method of valve timing with variable lift, phase, and duration.
2017-03-28
Technical Paper
2017-01-1063
Tonghang Zhao, Xining Liu, Meng Yang, Yulei He, Hangsheng Hou
In contrast with conventional ICE vehicles, hybrid electric vehicles have their unique power flow structure and operating conditions, which complicates HEV’s NVH performance and design. At present, the HEV programs are mostly carried over from their corresponding conventional counterparts for many OEM’s. As a result, the total vehicle weight will increase 10% to 15% compared to their conventional version. However, the vehicle structural characteristics, such as hard points and chassis suspension stiffness, still remains similar to their conventional version. Therefore, even under the same operating conditions, HEV’s might develop more serious and complicated NVH problems. In this work, the structural and operating characteristics of an HEV is briefly explained first. Based on the principle of vibration and noise control methodology, the most effective NVH control strategies under typical HEV operating conditions are looked into and presented.
2017-03-28
Technical Paper
2017-01-1122
Yashodhan V. Joshi
Vehicle noise has reduced over the years due to the customer demand for quieter vehicles. As engines have become quieter by efforts to reduce the combustion noise, as well as, by moving away from mechanical fuel pumps to common rail fuel pumps, the geartrain noise has come under increased scrutiny. Gear whine could be a result of multiple factors, and gear profile distortion is one of those factors. ISO 10064 provides guidance on the distortion due to temperature effects, but does not describe other influences in detail. There is not much published literature about gear whine due to profile distortion. The work attempts to fill that gap by describing a gear whine problem due to profile distortion and load change and it’s resolution by changing the gear design.
2017-03-28
Technical Paper
2017-01-0448
Prakash T. Thawani, Stephen Sinadinos, John zvonek
Prakash Thawani, Steve Sinadinos and John Zvonek DENSO International America Inc. Southfield, MI Abstract With the advent of EVs/HEVs and implementation of Idle-Stop-Start (ISS) technologies on internal combustion engine driven cars/trucks to improve fuel economy and reduce pollution, refrigerant sub-system (RSS) induced noise phenomena like, hissing, gurgling and tones become readily audible and can result in to Customer complaints and concerns. One of the key components that induces these noise phenomena is the Thermal Expansion Valve (TXV). The TXV throttles compressed refrigerant through the evaporator that results in air-conditioning (A/C) or thermal system comfort and defogging when needed. Under certain operating conditions, the flow of gas and/or liquid/gas refrigerant at high pressure and velocity excites audible acoustical and structural modes inherent in the tubing/evaporator/HVAC case.
2017-03-28
Technical Paper
2017-01-0444
Weiguo Zhang, Mark Likich, Brian Butler, John White
Engine air induction shell noise is a structure borne noise that radiates from the surface of the air induction system. The noise is driven by pulsating engine induction air and is perceived as annoying by vehicle passengers. The problem is aggravated by vehicle design demands for low weight components packaged in an increasingly tight under hood environment. Shell noise problems are often not discovered until production intent parts are available and tested on the vehicle. Part changes are often necessary which threatens program timing. Shell noise can negate air induction NVH development by overriding acoustic abatement features such as Helmholtz resonators and large air boxes. Shell noise should be analyzed in the air induction system design phase and a good shell noise analytical process and targets must be defined. A numerical analytical process is developed to predict the radiated sound power of air induction components.
2017-03-28
Technical Paper
2017-01-1051
Hassan nehme, Abdelkrim Zouani
Turbocharged engines constitute one of the strategies used by Ford Motor Company to deliver engines with improved fuel economy and performance. However, turbochargers exhibit many inherent NVH challenges that need to be addressed in order to deliver refined engines that meet customers’ expectations. One of these challenges is the turbocharger 1st order synchronous noise due to the interaction between the manufacturing tolerances of the rotating components and the dynamics of the rotor. This paper presents an analytical method to compute the turbocharger bearing forces and predict the 1st order synchronous noise and vibrations. The method consists of a fully coupled turbocharger rotor dynamic analysis in a flexible turbocharger housing structure; it predicts housing vibrations under various manufacturing tolerance conditions. The predicted vibrations of the turbocharger housing are compared to measured test data to demonstrate the validity of the analytical method.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya marri, Simon Antonov
In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to reduce friction and deliver stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during a complete shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise different porting geometries and vane spacing are used. This paper presents an optimization method intended to identify the best possible spacing for the conventional 7-vanes and 9-vanes oil pumps. The method integrates a Matlab based oil pressure trace model into Mode Frontier computation platform. Bench tests are performed on several pumps with different vane spacing to measure the harmonics of the pressure ripples at the pump outlet in order to validate the results of the optimization study.
2017-03-28
Technical Paper
2017-01-1061
Jiachen Zhai, Lu Cao
Electric vehicle driving permanent magnet synchronous motor has a wide speed range and load changes, with abundant harmonic currents, and its eccentric form is complex, which all result in poor sound quality and abnormal noise problems becoming increasingly prominent. To make a systematic and thorough study of the centralized drive permanent magnet synchronous motor (PMSM) is significant to ameliorate the sound quality and solve noise problems. MATLAB-based modeling technology, SPSS software, and the establishment of sound quality evaluation model for the centralized drive PMSM has a crucial reference value on the research and development of the electric vehicle driving permanent magnet synchronous motor. As for the sound quality of centralized drive PMSM, firstly, in order to get objective parameter values, evaluation models of objective parameters based on psychological acoustics should be established after the collection of the sound samples.
2017-03-28
Technical Paper
2017-01-1052
Paul Zeng, Vincent Solferino, Mark Stickler
Engine ticking noise is one of the key failure modes in today’s direct injection (DI) engines. High ticking noise results in high Things Gone Wrong (TGW) index, which negatively affects customer satisfaction. In this paper, the root cause of the ticking noise from DI injector in direct mounting will be presented. Design principle such as injector impact force to cylinder head and DI injector isolator design with 2 stage stiffness is proposed.
2017-03-28
Technical Paper
2017-01-1057
Paul Zeng, Debabrata Paul, Vincent Solferino, Mark Stickler
Valvetrain ticking noise is one of the key failure modes in noise vibration harshness (NVH) evaluation at idle. It affects customer satisfaction inversely. In this paper, the root cause of the valvetrain ticking noise and key parameters that impact ticking noise will be presented. A physics based math model has been developed and integrated into a parameterized multi-body dynamic model. The analytical prediction has been correlated with testing data. Valvetrain ticking noise control is discussed.
2017-03-28
Technical Paper
2017-01-1311
Suman Mishra, Nagesh Gummadi, Lloyd Bozzi, Neil Vaughn, Rob Higley
Air rush noise is exhaust gas driven flow induced noise in the frequency range of 500-6500 Hz. It is very essential to understand the flow physics of exhaust gases with in the mufflers in order to identify any counter measures that can attenuate this error state. This study is aimed at predicting the flow physics and hence of air rush noise of exhaust mufflers in the aforementioned frequency range at a typical exhaust flow rate and temperature. The study is performed on 2 different muffler designs which show a significant air rush noise level difference when tested on the vehicle. The transient computational study was performed using DES with 2nd order spatial discretization and 2nd order implicit scheme for temporal discretization in StarCCM+. To compare with test data, a special flow test stand is designed so that all high and low frequency contents emanating from the engine are attenuated before the flow enters the test part.
2017-03-28
Technical Paper
2017-01-1120
Kenji Tsutsumi, Yoshitaka Miura, Yusuke Kageyama, Arata Miyauchi
A CVT variator chain system is superior in efficiency to a variator belt system because of its lower internal friction. However, a chain produces more noise than a belt due to the long contact length between the rocker pins and pulley sheaves. This paper focuses on optimization of the link arrangement pattern (pitch sequence) in order to reduce chain noise. The current pitch sequence puts links of different lengths together appropriately and reduces the peak level of 1st-order chain noise by improving noise dispersibility. First, the object function for optimization was defined as the reduction of the peak level of 1st-order chain noise combined with a well-balanced chain noise level of low and high frequency bands. Road noise and wind noise as transmission background noise have the characteristic that they increase as the frequency decreases.
2017-03-28
Technical Paper
2017-01-1070
Da Shao, Xu Sichuan, Aimin Du
The electromagnetic valve actuator (EMVA) is considered a technological solution for decoupling between crankshaft and camshaft to improve engine performance, emissions, and fuel efficiency. Conventional EMVA consists of two electromagnets, an armature, and two springs has been proved to have the drawbacks of fixed lift, impact noise, complex control method and large power consumption. This paper proposes a new type of EMVA that use voice coil motor (VCM) as electromagnetic valve actuator. This new camless valvetrain (VEMA) is characterized by simple structure, flexible controllable and low actuating power. VCM provides an almost flat force versus stroke curve that is very useful for high precision trajectory control to achieve soft landing within simple control algorithm.
2017-03-28
Technical Paper
2017-01-1325
U Oh, Kusano Kazuya PhD, Nonaka Norihiko, Hironobu yamakawa
The automotive fuel could be efficiently combusted by injecting it into the cylinders with high pressure to atomize it to pass the regulations of exhaust gas and fuel economy. For this reason, automotive companies have developed DI (Direct Injection) engines, which can inject gasoline into the cylinders directly and compress the pressure of the cylinder highly. Furthermore, the demand for lower-noise high pressure pumps is also increasing from the viewpoint of automotive comfort. Since the valve velocity and noise level will increase with the increase of the pressure in fuel pumps, noise issues need to be solved under the high pressure condition. Accordingly, the valve motion should be predicted with high accuracy under operating conditions for evaluating the noise caused by valve impingement. In addition, the squeeze film effect phenomenon, which is pressure increasing between two plates when the two plates become close enough, will occur in the physical fuel pumps.
2017-03-28
Technical Paper
2017-01-1539
Vinh Long Phan, Hiroshi Tanaka, Takaaki Nagatani, Mikio Wakamatsu, Tsuyoshi Yasuki
Interior noises in high frequency of a passenger vehicle due to exterior wind noises induced by turbulent flow around the vicinity of the front pillars and front side glass are one of the most impact factors on customer feelings of riding comfort and their perception of quality of vehicle. In order to reduce such undesirable interior noises during vehicle development process, a calculation and visualization method for exterior wind noise with an acceptable computational cost and adequate accuracy is required. In this paper an index for prediction of the strength of exterior wind noise, referred to as Exterior Noise Power (ENP), is developed based on an assumption that the acoustic power of exterior wind noise can be approximated by the far field acoustic power radiated from vehicle surface.
2017-03-28
Technical Paper
2017-01-1064
Mustafa Yıldırım
Engine system is getting smaller in time and getting more powerful engine is main purpose of many OEMs. While engines are getting more powerful, by the time, it is also getting smaller and less stiff. Smaller engines with high power means, engine vibrates more and so generates more noise.Thus engine structure and also engine main components should be design to prevent this vibration. There are two main sources. One of them is combustion and other is inertia loads. Due to this sources engine structure can cause severe vibration and accordingly this can cause noise via transmitting it into vehicle with both structure and airborne. This paper focused on to reduce engine vibration level with changing the combustion inputs such as cylinder pressure parameters and also changing piston mass, conrod lenght and balancing parameters. Optimisation tool is used to obtain most robust design in terms of nvh.The combination of both engine structure and combustion is chosen to reduce vibration.
2017-03-28
Technical Paper
2017-01-1073
Robert Huber, Jan Clauberg
The object of this study is a new chain tensioner with two labyrinth seals. For the simulation of chain tensioners within the framework of multi-body dynamics, a physically orientated model to describe the fluid dynamics of the labyrinth seals is derived. The easiest way to describe labyrinth seals is to use maps obtained from measurements. As this is very time-consuming, methods of 1D and 2D fluid-mechanics are used in this work to model the labyrinth seals. The seals are characterized by physically motivated parameters e.g. coefficients of resistance or friction. As these parameters can be derived from geometric data, a very good forecast feasibility without experimental investigations is provided. For high accuracy simulations model parameters can be refined by experimental data. As many and highly complex parameters have to be identified, this refinement is very time-consuming and requires lots of experiments.
2017-03-28
Technical Paper
2017-01-0441
Zhenyu Wang, Mei Zhuang
A numerical study on sunroof noise reduction is carried out. One of the strategies to suppress the noise is to break down the strong vortices impinging upon the trailing edge of the sunroof into smaller eddies. In the current study, a serrated sunroof trailing edge with sinusoidal profiles of wavelengths is investigated for the buffeting noise reduction. A number of combinations of wavelengths and amplitudes of sinusoidal profiles is employed to examine the effects of trailing edge serrations on the noise reduction. A generic vehicle model is used in the study and a straight trailing edge is considered as a baseline. The results indicate that the trailing edge serration has a significant impact on the sound pressure level (SPL) in the vehicle cabin and it can reduce the SPL by up to 10~15 dB for the buffeting frequency.
2017-03-28
Technical Paper
2017-01-0447
Zhe Li, Mike Dong, Dennis Harrigan, Michael Gardner
In gasoline Powertrain systems, the evaporative emission control (EVAP) system canister purge valve (CPV) can be actuated by pulse-width modulated (PWM) signals. The CPV is an electronically actuated solenoid. The PWM controlled CPV, when actuated, creates pressure pulsations in the system. This pulsation is sent back to the rest of the EVAP system. Given the right conditions, the fill limit vent valve (FLVV) inside the fuel tank can be excited. The FLVV internal components can be excited and produce noise. This noise can be objectionable to the occupants. Additional components within the EVAP system may also be excited in a similar way. This paper presents a bench test method using parts from vehicle’s EVAP system and other key fuel system components.
2017-03-28
Technical Paper
2017-01-1130
Shinya Takamatsu, Nobuharu Imai, Koji Tsurumura, Seiji Yamashita, Hiroaki Tashiro
Renewed platform of upcoming flagship FR vehicle demands high levels of driving performance, fuel efficiency and noise-vibration performance. The newly developed driveline system must balance these conflicting performance attributes by adopting new technologies. This article focuses on several technologies that were needed in order to meet the demand for noise-vibration performance and fuel efficiency. For noise-vibration performance, this article will focus on propeller shaft booming noise. This noise level is determined by propeller shaft’s excitation force and sensitivity of differential mounting system. In regards to propeller shaft’s excitation force, the contribution of axial excitation force was clarified. This excitation force was decreased by adopting a double offset joint(DOJ) as propeller shaft’s second joint and low stiffness rubber couplings as first and third joint.
2017-03-28
Technical Paper
2017-01-0442
Harchetan Singh Aneja, Manas Tripathi, Harmeet Singh, Aashish Parmar
With increase in customer expectations for a quiet and comfortable ride, it has become the need of the hour for automobile manufacturers to continuously improve automobile powertrain NVH. Today's customer has become so aware of vehicle related noises that in-tank fuel pump noise is no exception to this checklist of evaluating cabin NVH. In-tank Fuel pump, that is responsible for delivering the fuel from fuel storage tank to delivery rail, uses an electric motor driven component. The rotating parts (rotor, etc.) produce vibrations that may traverse to tank body & subsequently the vehicle body. Since noise is essentially an audible vibration at its root, these structure borne vibrations may be perceived as noise inside passenger cabin. Additionally, noise may also be produced by fuel flow pulsations if transferred through the piping to the vehicle body. This paper focuses on various approaches to reduce the fuel pump generated noise heard inside passenger cabin.
2017-03-28
Technical Paper
2017-01-0449
Yinzhi He, Bin Wang, Zhe Shen, Zhigang Yang, Gunnar Heilmann, Tao Zhang, Guoxu Dong
Beamforming technique is today widely used in aeroacoustic wind tunnel to identify wind noise sources generated by interaction between incoming flow and test object. In this study, a planar spiral microphone array with 120 channels was set out-of –flow of 1:1 aeroacoustic wind tunnel of Shanghai Automotive Wind Tunnel Center (SAWTC) to test exterior noise sources of a production car. Simultaneously, 2 reference microphones were set in vehicle interior to record potential sound source signals synchronously and a spherical array with 48 channels inside the vehicle to identify interior noise sources. With different correlation methods and some advanced algorithms, i.e. using CSM and Clean-Sc, the ranking of contributions of vehicle exterior wind noise sources to interested interior noise locations was accomplished. Hereby, Correlation analysis results of interior and exterior noise sources using virtual and real reference microphones are compared and discussed.
2017-03-28
Technical Paper
2017-01-1055
Baolin Yu, Zhi fu, T. Bin Juang
The automotive industry is experiencing a profound change due to increasing pressure from environmental and energy concerns. This leads many auto makers to accelerate hybrid and electric vehicle development. Generally smaller engines utilized by hybrid and electric vehicles lend themselves to quieter operation. However, customer satisfaction could be negatively impacted by the peak whine emitted by electric motor. Unlike conventional gas vehicles, the strategy for reducing motor whine is still largely unexplored. This paper presents an analytical study on electric motor whine radiated from a hybrid vehicle transmission. The analysis includes two stages. Firstly a detailed finite element (FE) model of transmission is constructed, and case surface velocities are calculated utilizing electromagnetic force. Then a boundary element model is built for evaluating noise radiated from the transmission surface using acoustic transfer vector (ATV) method.
2017-03-28
Technical Paper
2017-01-1125
Victor Baumhardt, Valdinei Sczibor
Halfshafts are very important components from vehicle powertrain. They are the element responsible to transmit torque and rotation from transmission to wheels. Its most basic design consist of a solid bar with joints at each extreme, however, Depending of its length, the natural frequency of first bending mode might have a modal alignment with engine second order, resulting in undesired noise on vehicle interior. Many design alternatives are available to overpass this particular situation, like adding dampers, use tube shafts or use link-shafts, however, all of them are cost affected. The aim of this study is to propose an optimal halfshaft profile for a solid shaft to be machined from a rough bar, pursuing the lowest frequency the possible for the first bending mode by changing its diameter and, as a consequence, the mass and bending stiffness at appropriate regions.
2017-03-28
Technical Paper
2017-01-1465
William R. Bussone, Joseph Olberding, Michael Prange
At present, SAE J211 provides no definitive guidance as to the appropriate procedures for filtering angular rate sensor data prior to differentiation into angular acceleration data, especially for very short duration or impact data. Accordingly, a 3-2-2-2 array of linear accelerometers and a triaxial angular rate sensor were mounted into a Hybrid III 50th percentile male ATD headform and compared in a variety of impact events. An appropriate low-pass digital filter cutoff frequency for differentiating the angular rate sensor data into angular accelerations was sought via residual analysis in accordance with current SAE J211 guidelines to find appropriate cutoff frequencies which would best match the angular acceleration data measured by the 3-2-2-2 array, which is the present gold standard.
2017-03-28
Technical Paper
2017-01-1121
Deb Bonnerjee, Djamel Bouzit, Javed Iqbal
Ting noise has a significant contribution to the driver’s perceivable transient NVH during acceleration from a stop or while driving. This metallic noise can be present in vehicles with any variant of the driveline architecture (FWD, AWD, RWD and 4X4). This paper details the generation mechanism of the noise excitation and defines the physical and design parameters that influence it. This paper will focus on the noise generated between halfshaft to wheel hub interface. Same phenomena apply to all other torque transferring components that use axial splines assembled with specified nut torque. Bench tests were conducted measuring the transient noise generated when powertrain torque is applied to the halfshaft which moves relative to wheel hub after overcoming the frictional torque. The properties of two interfacing surfaces (halfshaft joint tulip and wheel hub) are studied; including coefficient of friction and design features.
2017-03-28
Technical Paper
2017-01-1693
John Huber, Ranjani Rangarajan, An Ji, Francois Charette, Scott Amman, Joshua Wheeler, Brigitte richardson
In-Vehicle speech recognition robustness is a challenge to the automotive industry. Factors such as background noise level and microphone placement affect how well the system performs. Live hardware validation using on-road testing with subjects of varying accent and cultural background can be both costly and time consuming. In addition, it is arguably impractical to collect a statistically significant amount of data to draw proper conclusions on the results. This paper describes a method to validate in-vehicle speech recognition by combining synthetically mixed speech and noise samples with batch speech recognition. Vehicle cabin noises are pre-recorded along with the impulse response from the driver's mouth location to the cabin microphone location. These signals are combined with a catalog of speech utterances to generate a noisy speech corpus. Speech scaling to simulate the Lombard effect of raising ones voice in a noisy environment is a critical piece.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu
Aiming at the variable displacement oil pump, the modal and noise were studied, and structural optimization and test verification were carried out. The modal analysis of the variable displacement oil pump was carried out by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. Sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment. The modal of the variable displacement oil pump was analyzed by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. The sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment.
2017-01-15
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