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2015-04-14
Technical Paper
2015-01-1667
Yasunori Kanda, Tsunehiro Mori
It has been required recently that diesel engines for passenger cars meet various requirements, such as low noise, low fuel consumption, high power and strict emission limits. The key to decrease the noise is to reduce a combustion noise known as “Diesel knock”. Conventional approaches to reduce the diesel knock are decreasing combustion excitation force due to pilot/pre fuel injection, adding ribs to engine blocks or improving noise transfer characteristics by using insulation covers. However, these approaches have negative effects, such as deterioration in fuel economy and increase in cost/weight. Therefore, modification of engine structures is required to reduce it. We analyzed noise transfer paths from a piston, a con rod, a crank shaft to an engine block and vibration behavior during engine operation experimentally, and identified that piston resonance was a noise source.
2015-04-14
Technical Paper
2015-01-1668
Chetankumar Patel, Nachiketa Tiwari, Avinash Kumar Agarwal
High viscosity of vegetable oil causes problems while using them as alternate fuel for compression ignition engines. There is a need to reduce the viscosity before using them as engine fuel. Preheating and pre-treating of vegetable oils using waste heat of exhaust gases is one of the techniques, which reduces the viscosity and makes it possible to use as alternate fuel for some niche applications, without major modifications in the engine hardware. There are several applications in developing countries such as decentralised power generation, agricultural engines, and water pumping engines, where vegetable oils can play a significant role as an alternate fuel. In present investigations, performance, combustion, emission characteristics of an engine using preheated Jatropha oil (J100) and 20% blend of Jatropha oil with mineral diesel (J20) have been evaluated at a constant speed (1500 rpm) in a single cylinder four stroke direct injection diesel engine.
2015-04-14
Technical Paper
2015-01-1669
Alexei P. Popov, George Nerubenko
Increasing challenges on reducing fuel consumption has opened the new directions in Automobile Powertrain technologies. The example of such technology implemented in geared transmission is the usage of novel type of gears with 3D point system of mesh engaging invented, patented and developed by Alexei P. Popov. The paper identifies the milestones of R&D that were undertaken to create the new type of geared transmission which could be used in vehicles. Using the Winkler hypothesis Alexei P. Popov had developed and designed new type of point contact which made possible to lower a contact stresses significantly in comparison to the values of a contact stresses for teeth having linear contacting interaction. The new profile and shape of tooth was invented and the methodological tools were developed for engineers providing the formulas for design and forming geometry of tooth with high stress capacity.
2015-04-14
Technical Paper
2015-01-1665
Nicolas Arnault, Adrien Baudet, Nicolas Becker
Vehicle integration in today society and especially in urban zones is the one of the main focus of regulators as well as car manufacturers. Indeed, vehicles impact on everyday life as air quality, noise, traffic density, urban spaces occupied by parked cars, among others is scrutinized and leads to at least significant efforts, but often to major improvements on all those topics. Noise is one of the key nuisances from which the car is the source. There are already some existing regulations, and they intend to become stricter and stricter. The perfect example of this trend is the recent new European Commission regulation adopted in April 2014, which requires a fair reduction of the allowable emitted noise, but may also introduce performance labels. Of course, there are solutions to deal with noise emissions.
2015-04-14
Technical Paper
2015-01-1674
Takashi Hoshi
For multi plate wet clutches in transmission systems, an understanding of the dynamic frictional characteristics of the friction surfaces and damping characteristics of the drivetrain are essential in predicting self-excited vibration. We made a test apparatus for torque transmission characteristics and measured the dynamic frictional characteristics of the friction surfaces at a uniform contact pressure. An understanding was gained of the changes in dynamic frictional characteristics due to temperature and contact pressure relating to the sliding velocity. We also obtained the damping characteristics by measuring the torque loss due to drivetrain friction. We created a clutch FEM model to gain a quantitative understanding of how to implement the dynamic frictional characteristics. Taking the damping characteristics of the drivetrain into consideration, we also made a plant model encompassing all areas from the transmission to the vehicle body.
2015-04-14
Technical Paper
2015-01-0664
Hiroko Tada
We optimized the soundproof packages. This optimization study should be done in the early stage of vehicle development. The process for improving automotive interior quietness includes setting the marketability targets, the vehicle body acoustical performances, and the parts specifications. The acoustical system performance in this process is accomplished by evaluating the acoustical energy level of each system with the unit power of the exterior speaker excitation. The system was defined as the partial surface of the interior cavity, and one interior cavity surface was divided into a number of systems. Each system includes panel, damping material and exterior and interior soundproof packages. This system performance is named as the Energy Transmission Loss (ETL). The applicability of the method with ETL was verified by evaluating the results against the predicted values using the new method with the vehicle operation on a chasse-dynamometer.
2015-04-14
Technical Paper
2015-01-0663
Ling Zheng, Zhanpeng Fang, Zhongcai Tang, Zhenfei Zhan, Jiang-hua FU
The design optimization of vehicle body structure is addressed to reduce interior noise and improve customer satisfaction in this paper. The structural-acoustic model is established and the response of sound pressure in frequency domain is obtained by using finite element method. The minimization of sound pressure near the driver’s right ear depends on the geometry of vehicle body structure and the layout of damping treatments. The panel participation analysis is performed to find out the key panels as design variables and improve the efficiency of optimization computation. Response Surface Method (RSM) is utilized to optimize the vibro-acoustic properties of vehicle body structure instead of complex structural-acoustic coupling finite element model. Structural-acoustic problem is approximated by a series of quadratic polynomial using RSM. Geometric optimization problem of panels is described and solved to minimize the interior noise in vehicle.
2015-04-14
Technical Paper
2015-01-1124
Gerrit Knabe, Markus Zahlten, Ferit Kücükay
In order to improve the acoustic comfort inside passenger cars in terms of transmission noise, a special method has been developed. For a structured and comprehensive analysis of the transmission noise, the generation and transfer mechanisms are divided into four separate but nevertheless connected parts. Although simulation and components tests are used to analyze vibration excitation which may cause rattle and the mechanisms causing rattle in detail, they are not the main part of the analysis. The focus of this study is on the transfer of automotive transmission rattle and the passengers’ perception. The noise characteristics, which can be specified using conventional analysis methods as well as assessments by test persons, are important for the transfer path of the disturbing noise. By combining different methods of transfer path analysis (TPA), direct airborne-sound transmission is identified as a significant transfer path of the rattling noise.
2015-04-14
Technical Paper
2015-01-1122
Kengo Yabe, Toru Inagaki, Takashi Kondo
Seat vibration when the vehicle is idling and when it is in motion has been reduced by using a floating seat that controls the resonance frequencies. The resonance frequency is controlled by replacing the structures of the seat-mounting unit with floating structures using rubber bushings. Partly replacing the mounting unit with floating structures makes it possible to control the resonance frequencies of the entire seat. The issue of balancing vibration reduction with strength and durability and crash safety performance due to fitting rubber bushings to the seat-mounting unit was addressed using stopper structures optimized for each type of input. To adopt a floating seat into an actual vehicle, the floating structure and conventional foot bracket are combined. This combined foot bracket not only makes it easy to assemble floating structure into the seat, but also makes it possible to keep the seat weight almost the same as a conventional seat.
2015-04-14
Technical Paper
2015-01-1123
Jiangwu Zhang, Donghao Liu, Haisheng Yu
Torsional vibrations of the full hybrid electric vehicle driveline with a novel single-mode power-split transmission are investigated, in which three power sources, internal combustion engine (ICE), motor/generator 1 (MG1) and motor/generator 2 (MG2) are equipped. The compound planetary gear unit inside the transmission provides the driveline output with continuously variable gear ratios and serves as a power splitting device. Though very similar in configuration, the compound planetary gear used herein is a novel variation of Ravigneaux planetary gear set. MG1, MG2 and ICE are connected to the small sun gear (S1), the large sun gear (S2), the planetary carrier (C), respectively. The ring gear (R) is connected to the final reduction gear (FR), outputting tractions by the conventional differential (DF) to the right and left half shafts for the front wheels.
2015-04-14
Technical Paper
2015-01-0667
Kei Ichikawa
The importance of reducing road noise is increasing . Methods that enhance acoustic sensitivity and reduce the force transferred from the suspension to the body are used to reduce road noise. Reduction of body suspension mounting point compliance has been used as a method of reducing acoustic sensitivity. There were cases where this method reduced acoustic sensitivity, the road noise pressure was not reduced; this study focused on the suspension transfer force and analyzed its mechanism of change using the Transfer Function Synthesis Method. The results showed that the balance between the body suspension mounting point, suspension bush and suspension arm tip compliance is an important factor influencing the change in suspension transfer force.
2015-04-14
Technical Paper
2015-01-1506
Bastian Scheurich, Tilo Koch, Michael Frey, Frank Gauterin
Today, body vibration energy of passenger cars gets dissipated by linear working shock absorbers. A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and to store vibration energy. A gyroscope is set to high speed revolutions by an electric motor and a gimbal is used for bearing. The gimbal consists of an outer ring which is connected to the vertical movement of the wheel carrier. Right-angled to the outer ring, there is an inner ring pivoting the gyroscope right-angled. In order to avoid undesirable body movements, the directional vector of the angular velocity of the gyroscope is parallel to the car’s yaw axis.
2015-04-14
Technical Paper
2015-01-0660
Kosuke Sakamoto, Toshio Inoue
When a vehicle is in motion, noise is generated in the cabin that is composed of multiple narrow-frequency bands from input from the road surface. This type of noise is termed low-frequency-band road noise, and its reduction is sought to increase occupant comfort. The research discussed in this paper used feedback control technology for the development of an active noise control technology able to simultaneously reduce noise in multiple narrow-frequency bands. We investigated methods of connecting multiple single-frequency adaptive notch filters, a type of adaptive filter. We tested a method of connecting multiple filters that mitigates mutual interference caused by different controller transmission characteristics. This method made it possible to implement controllers with amplitude and phase characteristics in multiple narrow-frequency bands corresponding to design values, and to achieve the target noise-reduction.
2015-04-14
Technical Paper
2015-01-0661
Jianwang Shao, Xian Wu, Na Wei, Ding Wang, Guoming Deng, Ming Xu
An increasing demand for vehicle noise control has been proposed and at the same time, vehicle weight and fuel economy have become critical for the automotive industry. The methodology of statistical energy analysis (SEA) is used to balance both light weight and high noise insulation performance. In this paper, the vehicle dash and floor sound package systems, which are two of the major paths for vehicle interior noise, are studied and optimized by CAE and testing technology. Two types of sound package which are the conventional insulation system and the lightweight one are chosen for the vehicle dash and floor system. The vehicle dash and floor systems are modeled by SEA and the transmission loss (TL) of the dash and floor system is analyzed, respectively. Several influence factors of the TL are also analyzed, such as sound package coverage, the leaks, etc.
2015-04-14
Technical Paper
2015-01-0662
Weiguo Zhang, Mac Lynch, Robert Reynolds
A turbocharger is currently widely used to boost performance of an internal combustion engine. Generally, a turbocharger consists of a compressor which normally is driven by an exhaust turbine. Both the compressor and the turbine will have an influence on how the low frequency engine pulsation propagates in the intake and exhaust system. In addition, the turbocharger will produce high frequency flow induced sound. The high frequency sound generation is associated with rotating blade pressures, supersonic tip speeds or rotating shock waves. This paper focuses on the application of computational fluid dynamics (CFD) to the prediction of this high frequency flow induced sound. A turbocharger compressor is generally a centrifugal compressor consisting of wheel, diffuser and housing. As the compressor wheel rotates, ambient air is drawn in axially through an air induction system, accelerated to high speed and then expelled in a radial direction to the outlet.
2015-04-14
Technical Paper
2015-01-0796
Stephen Busch, Kan Zha, Paul C. Miles, Alok Warey, Francesco Pesce, Richard Peterson, Alberto Vassallo
Various pilot-main injection strategies are investigated for a part-load operating point in a single cylinder optical Diesel engine. With a pilot injection energizing signal that is advanced from the main injection by 300 µs or more, a 9 dB reduction in combustion noise is achieved. It is observed that as the energizing dwell between a single pilot and the main injection is decreased below 200 µs, combustion noise passes through a minimum and a further reduction of 3 dB is possible. This additional decrease in combustion noise is not associated with increases in smoke or NOx emissions. The injection schedules employed in the engine are analyzed with a hydraulic injection analyzer to provide rate shapes for each of the dwells tested. Two distinct injection events are observed even at the shortest dwell tested, and various rate shaping effects are observed with the main injection event as the dwell is adjusted.
2015-04-14
Technical Paper
2015-01-1675
Yongfu Chen, Zhengfei Tang, Peijun Xu, Yunqing Zhang
A method for dynamic analysis and design of Powertrain Mounting System(PMS) is developed with the aim of reducing the vibration of the PMS, which is very significant to improve ride comfort. A nine degrees of freedom(DoF) dynamic model is established, including a powertrain and a chassis. The dynamic stiffness of the mounting is taken as the design parameter. Decreasing the dynamic force between the powertrain and the frame is the optimization objective. The initial values of the dynamic stiffness are obtained by finite element analysis. Due to the frequency dependence of dynamic stiffness, the dynamic stiffness is optimized at lower frequency section and high frequency section respectively. In addition, the deformation of the mounting under the gravity of powertrain is limited, which further determines the range of dynamic stiffness.
2015-04-14
Technical Paper
2015-01-1670
Can Tao, Hengjia Zhu, Peijun Xu, Yunqing Zhang
Hydraulic Engine Mount (HEM) is widely used in vehicle Powertrain Mounting System (PMS) for vibration isolation. The dynamic performances of an HEM are strongly frequency dependent. A Five-Parameters Fractional Derivative model is used to describe the dynamic properties of a HEM. A 1/4 and 1/2 car model are applied to evaluate the effect of frequency-dependent dynamic stiffness which using measured data of a typical hydraulic engine mount. The excitations from engine and road are considered in the simulation. The generalized- method is presented to solve the vehicle model with Five-Parameters Fractional Derivative model.
2015-04-14
Technical Paper
2015-01-0665
Yongchang DU, Yujian Wang, Pu Gao, Yingping Lv
Modelling of disc in brake squeal analysis is complicated because of the rotation of disc and the sliding contact between disc and pads. Many analytical or analytical numerical combined modeling methods have been developed considering the disc brake vibration and squeal as a moving load problem. Yet in the most common used complex eigenvalue analysis method, the moving load nature normally has been ignored. In this paper, a new modelling method for rotating disc from the point of view of modal is presented. First finite element model of stationary disc is built and modal parameters are calculated. Then the dynamic response of rotating disc which is excited and observed at spatial fixed positions is studied. The frequency response function is derived through space and time transformation. The equivalent modal parameter is extracted and expressed as the function of rotation speed and original stationary status modal parameters.
2015-04-14
Technical Paper
2015-01-1666
Lingzhi Li, Yimin Yang, Fengjun Zhao, Zhi Zhang, Hailong Cheng, Hangsheng Hou
An issue of engine squealing in low temperature range (around -25C) right after start-up emerged for a significant number of vehicles in a program. The squealing noise typically only lasted for a few seconds. The earlier effort had focused on typical common culprits such as the pulley-belt systems etc. However, much effort, by subjective listening, yielded no fruitful results for more than a year. The application of near-field acoustic holography on top of the engine in a climate chamber quickly identified several noise source locations. Further noise source identification on the top, front and left sides of the engine pinpointed the top three noise source locations: the idler pulley and the water pump on the front side, the air compressor on the right side, and the air intake throttle on the top. Then a series of experiments were conducted.
2015-04-14
Technical Paper
2015-01-0668
Yongchang DU, Pu Gao, Yujian Wang, Yingping Lv
The study and prevention of unstable vibration is a challenging task for vehicle industry. Improving predicting accuracy of braking squeal modal is of great concern. Closed-loop coupling disc brake model is widely used in complex eigenvalue analysis and further analysis. The coupling stiffness of disc rotor and pads is one of the most important parameters in the model. But in most studies the stiffness is calculated by simple static force-deformation simulation. In this paper, a closed-loop coupling disc brake model is built. Initial values of coupling stiffness are estimated from static calculation. Experiment modal analysis of stationary disc brake system with brake line pressure and brake torques applied is conducted. Then an optimization process is initiated to minimize the differences between modal frequencies predicted by the stationary model and those from test. Thus model parameters more close to reality are found.
2015-04-14
Technical Paper
2015-01-1088
Tomohiko Usui, Tomoya Okaji, Tatsuya Muramatsu, Yoshiyuki Yamashita
A low-cost lock-up damper displaying a high level of damping performance has been developed for use in torque converters in automatic transmissions. The new damper was actualized by sharing parts (the turbine and damper components) and optimizing parameters for damping characteristics. The new torque converter displays equivalent conversion performance to a conventional model while reducing the width of the torus by approximately 30%. The combination of the lock-up damper and the small torus has made it possible to reduce torque fluctuation transmitted to the transmission to less than 50% with no increase in the overall width of the torque converter against a conventional model. This has reduced engine speed when the vehicle is cruising by 400rpm, resulting in an increase in fuel efficiency of approximately 2%.
2015-04-14
Technical Paper
2015-01-1326
Guru Prasad Mani, Sundaravadivelu M, Kavin Raja
Generation of discretization with prescribed element sizes are adapted to the geometry. From Rules of thumb, for a complicated geometry it is important to select the reasonable element order, shapes and size for accurate results. In order to that, this paper describes the influence of elemental algorithm of the catalytic converter mounting brackets. Brackets are main source of mounting of various systems mainly intake and exhaust in the engine .In exhaust hot end system, bracket designs play a vital role because it has to withstand heavy structural vibrations without isolation combined with thermal loads. Bracket design and stiffness determines the whole Catalytic converter system's rigidity. So, here discretization of converter brackets by linear and parabolic elements is studied with different elements types and compared.
2015-04-14
Technical Paper
2015-01-0216
Ping-Min Hsu, Ming Hung Li, Kuo-Ching Chang
This paper studies noise filtering in an autonomous emergency braking (AEB) system with a sensor fusion between a millimeter wave (MMW) radar and a camera. The AEB system may automatically brake cars by mistake due to the sudden appearance of noise signal if it does not involve any noise filtering mechanism for the object sensor. This may cause some accidents. To avoid such accidents, we propose the filters for three kinds of noise—named as twice harmonic noise, ground noise, and specular refection noise—which are commonly suffered while applying MMW radars. The former is caused by the reflection of a radar wave between a target object and the MMW radar. Based on the concern that the MMW radar evaluates the sensing distance based on the time interval between the transmitting and receiving of the radar wave, one of the sensing distances would be twice as longer as one of others due to the wave reflection. The object featuring this characteristic is further filtered.
2015-04-14
Technical Paper
2015-01-0666
Chenguang Li, Fue-sang Lien, Eugene Yee, Mike Dong
A deeper understanding of the complex phenomenology associated with the flow induced noise and vibration in a dynamic valve is of critical importance to the automotive industry. To this purpose, a two-dimensional axisymmetric numerical model has been developed to simulate the complex processes that are responsible for the noise and vibration in a poppet valve (or poppet). More specifically, an Eulerian multiphase flow model, a dynamic mesh and a user-defined function are utilized within the ANSYS-FLUENT software system in order to facilitate the modeling of the complicated two-phase fluid-structure interaction problem associated with the generation of noise and vibration in a poppet valve. In this strongly coupled simulation framework, the poppet valve which is driven by spring and various dynamical fluid forces (e.g., viscous and pressure forces), is modeled as an under-damped vibration system.
2015-04-14
Technical Paper
2015-01-1597
Kazuto Yokoyama, Masahiro Iezawa, Hideyuki Tanaka, Keiichi Enoki
Mitsubishi Electric has developed a concept car “EMIRAI 2 xEV” that features an electric vehicle (EV) powertrain for safe, comfortable, and eco-friendly driving experiences in the future. The body of vehicle was exhibited during Tokyo Motor Show 2013 for the first time. xEV is a four-wheel-drive EV that has three motors: a water-cooled front motor and two air-cooled rear motors with integrated inverters. Rear wheels can be driven independently. The degrees of freedom of the actuation can realize improved maneuverability and safety. The vehicle is also equipped with an onboard charger with built-in step down DC/DC converter, an EV control unit, a battery management unit, and an electric power steering. All of the instruments are developed in Mitsubishi Electric Corporation. Motion control systems for xEV have been developed on the basis of our proprietary original motor control technology.
2015-04-14
Technical Paper
2015-01-1087
Juergen Greiner, Martin Grumbach, Albert Dick
This is a preliminary version of the abstract to save the date, it will be replaced after discussion with the main author Dr. Jürgen Greiner ZF in short time. The discussion was not possible earlier, due to vacation of the authors and other stakeholders. Marketresearch shows the ongoing worldwide increasing acceptance and success of modern automatic transmissions in passenger cars. This success is based on the further developed of the driving comfort, shifting dynamic and - most important - fuel consumption reduction modern transmission systems show.
2015-04-14
Technical Paper
2015-01-1671
Mohamed El-Morsy, Gabriela Achtenova
In this paper, a fault in rolling bearing is diagnosed using time waveform analysis. In order to verify the ability of time waveform analysis in fault diagnosis of rolling bearing, an artificial fault is introduced in vehicle gearbox bearing: an orthogonal placed groove on the inner race with the initial width of 0.65 mm approximately. The faulted bearing is a roller bearing located on the gearbox input shaft – on the clutch side. An optimal Morlet Wavelet Filter and autocorrelation enhancement are applied in this paper. First, to eliminate the frequency associated with interferential vibrations, the vibration signal is filtered with a band-pass filter determined by a Morlet wavelet whose parameters are optimized based on maximum Kurtosis. Then, to further reduce the residual in-band noise and highlight the periodic impulsive feature, autocorrelation enhancement is applied to the filtered signal.
2015-04-14
Technical Paper
2015-01-0610
Guangqiang Wu, Wenbo Luan
During the launch of a car, severe torsional vibration sometimes may occur in its driveline due to somewhat the slipping of the clutch, its intuitive sense for an occupant is the longitudinal vibration of the vehicle, referred to as the launch shudder, whose characteristic frequency is from 5 to 25 Hz generally. As the main vibratory sources of the driveline and its crucial nonlinear components, variable stiffness and backlash of the gear meshing are considered, their impacts on launch shudder are analyzed in this paper. Conformal mapping, finite element method and regression method etc. are the main approaches to calculate the variable meshing stiffness of a gear pair. If this stiffness is get, it can usually be substituted for its approximate analytical expression, or just with finite harmonic terms, in Fourier series form into Ordinary Differential Equations(ODEs) to calculate the vehicle responses considering its nonlinearity.
2015-04-14
Technical Paper
2015-01-1329
Katsutomo Kanai, Hideki Katsuyama
We developed a method of predictive simulation of flow-induced noise using computational fluid dynamics. Because the goal was to employ the method in the automotive development process, development sought to balance practical predictive accuracy and computation time. In order to simulate flow-induced noise, detailed eddy flows and changes in the density of the air must be computed. In the development discussed in this paper, we conducted unsteady-state compressible computations using large eddy simulation, a type of turbulence modeling, to predict whether flow-induced noise would occur. The target flow-induced noise was narrow-band noise, also known as whistling noise, a type of noise that increases in a specific frequency range. The target area of generation of flow-induced noise was set as the exhaust pipe, which incorporates the complex shape of the muffler.
Viewing 1 to 30 of 6979

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