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2014-11-11
Technical Paper
2014-32-0123
Vishnu Kumar Kuduva Shanthulal, Kannan Marudachalam, V Pattabiraman, S Jabez Dhinagar, Chandramouli Padmanabhan
The diesel power train (engine and transmission) is the most significant mass contributor in a three- wheeled vehicle. High idling vibrations of a single cylinder four-stroke diesel engine causes discomfort for driver and passengers as vibrations from the engine get transmitted to the structure and the body panels through the engine mounts. The 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; the engine and transmission are assumed to behave as a rigid body (6 degrees-of-freedom) and the compliance comes from the mounts. Both four and three mount configurations have been investigated, with the mounts being represented by three independent springs in the compression and shear modes. Since the mounts can be inclined, appropriate transformations are carried out from the local mount co-ordinate system to the global co-ordinate system.
2014-11-11
Technical Paper
2014-32-0121
Kazuhiko Tanaka, Haruomi Sugita, Hibiki Saito, Masahiko Sekita
The exhaust sound of a motorcycle is one of the key appealing factors to the customers along with its styling and dynamic performances. Accordingly, various attempts have been made to realize attractiveness of exhaust sounds. Recently, there is an increasing demand to divert a common motorcycle engine to various vehicle categories. An individual engine configuration category has its own featuring exhaust sound. Despite of these circumstances, it is also required to create the best suitable sound for each vehicle category with a specific vehicle feature. Accordingly, there is a possible case in which an inline-four-cylinder engine is shared with another motorcycle model in the vehicle category with nostalgic appearances in which V-twin engine flavor is frequently featured. In this study, three essential factors were extracted from the verbal expressions that appear as adjectives, exclusively or commonly, used to illustrate the exhaust sounds in each vehicle category or engine type. We tried to develop a method applicable to various engine types to design a targeting exhaust sound, by clarifying the relationship between the position of each exhaust sound, appeared on the mapping chart for the three factors, and the feature of the waveform of the sound,.
2014-11-11
Technical Paper
2014-32-0122
Andrea Fioravanti, Giulio Lenzi, Giovanni Vichi, Giovanni Ferrara, Stefano Ricci, Leonardo Bagnoli
The intake and exhaust lines are the main elements contributing to the abatement of the acoustic emissions of an Internal Combustion Engine (ICE). Many different numerical approaches can be used to evaluate their acoustic attenuation, which is commonly expressed by the Transmission Loss. One-dimensional (1D) and three-dimensional (3D) simulations are conventionally carried out only within the acoustic domain of the muffler or the air-box. The walls of the acoustic filter are considered fully rigid and the interaction between the acoustic waves and the structure is then neglected. Moreover, the effect of the manufacturing characteristics and the attenuation of the acoustic waves due to the fluid viscothermal effects are also commonly disregarded in the numerical analysis of the filters. In addition the presence of a catalytic converter or a filter cartridge may have an influence on the numerical results. All these aspects, however, can remarkably affect the matching between simulations and experiments both at high frequencies and also at medium-low ones.
2014-11-11
Technical Paper
2014-32-0120
Sara Gronchi, Riccardo Maccherini, Raffaele Squarcini, Fabio Guglielmo, Emanuela Ligarò
In the modern both small and large size engine, 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. Measurements have been carried out by means of the intensimetric method and supported also by conventional acquisitions performed with hydraulic pressure transducers, accelerometers and microphones.
2014-11-11
Technical Paper
2014-32-0119
Diego Copiello, Ze Zhou, Gregory Lielens
This paper addresses the numerical simulation of vehicle exhaust system noise using an innovative transfer matrix method (TMM) supporting high order duct modes combined with finite element method (FEM). Exhaust systems usually consist of complex volume components (mufflers, catalyzers ...) connected by simpler pipes. The noise propagation through such systems can be efficiently addressed by means of the Transfer Matrix Method (TMM). The TMM is an analytical method which allows assessing efficiently the acoustic behavior of an entire exhaust line by combining acoustic transfer matrices of each of its constitu¬ent sub-components (i.e., volume components: mufflers, catalyzers, etc.). The main assumption of this method is that within the exhaust line only the plane wave is propagating and thus the transfer matrices could be computed analytically. On the contrary, this assumption leads to a strong limitation in the maximum frequency of analysis which is the cut off frequency of the first higher order mode present in any one of the exhaust line components.
2014-11-11
Technical Paper
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. The comparison between the test and FE results proved that only a tuned FE model provides reliable results.
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. This study shows the various steps carried out on the multibody modeling of the IC engine components including engine crankshaft and their orientations.
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. Based on these results, this paper will also discuss the effect of the stiffness of the main bearings on combustion noise.
2014-11-11
Technical Paper
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. In this study, we focused clarifying these relationships and we took four study steps shown below: 1 Narrowing down the motorcycle specifications affecting shimmy2 Determining physical parameters influential to shimmy3 Investigating how a change of physical parameters affects shimmy using simplified model4 Analyzing how the changes of motorcycle specifications affect the shimmy Following these steps, we clarified the relationships between motorcycle's specifications and shimmy by using only three physical parameters.
2014-10-17
Article
Supercritical Fluid Technologies’ bench top supercritical fluid extractor, the model SFT-110, provides an alternative to traditional extraction methods that use organic solvents.
2014-10-17
Article
W. L. Gore & Associates is expanding its family of high-speed data cables for the aerospace industry to meet the industry’s challenges to improve pilot communication and passenger in-flight entertainment while reducing downtime for maintenance and decreasing operating costs.
2014-10-17
Article
The OM-WLS-TEMP series wireless USB 2.0 full-speed temperature input module from Omega is fully compatible with both USB 1.1 and 2.0.
2014-10-17
Article
WITT-Gasetechnik’s dome-loaded pressure regulator is impervious to system pressure and withdrawal fluctuations.
2014-10-13
Article
Researchers at VE Commercial Vehicles Ltd. in India employed downsizing to design a commercial vehicle exhaust system using the ANSYS CFD tool Fluent, resulting in a 14.1% reductions in both size and volume and a mass savings of 2%.
2014-10-13
Technical Paper
2014-01-2703
Xiuliang Zhao, Yong Cheng, Limei Wang
Abstract The surface vibration signals are widely used since they have much combustion information. However, for an Internal Combustion Engine (ICE), the measured surface vibration signals are difficult to utilize because they contain non in-cylinder pressure excitation response. The vibration response signals excited by the in-cylinder pressure excitation (ICPE) and the reciprocating inertia force excitation (RIFE) are overlapped in both time and frequency domain. That means they cannot be separated effectively by conventional signal processing method. In this paper, a new strategy to extract ICPE response from measured vibration signals by pattern recognition method is proposed. A model is established to describe the RIFE response. Then, the RIFE response could be predicted and subtracted directly from the measured vibration velocity signals. The processing results indicate that a fourth-order model and the data of initial compression stroke can reach satisfactory results. The impact of the speed fluctuation can be ignored.
2014-10-13
Technical Paper
2014-01-2867
Zhiyong Chen, Zhiyuan Chen, Yang Mao, Wenku Shi, Guihui Zhang
Abstract To research the torsional vibration damping characteristic of magneto-rheological fluid dual mass flywheel (MRF-DMF) and the control system in power train, the multi-degree power train torsional vibration model which contains MRF-DMF and semi-active fuzzy control model are built, then the damping characteristic of MRF-DMF in several conditions are gained and compared with MRF-DMF when no control system. The result indicates: the damping characteristic of MRF-DMF effect on power train when using control is better than without control in idle, speed up, slow down, ignition and stalling, while the damping characteristic is less obvious in constant speed because the simulation condition and damping moment relatively stable.
2014-10-13
Technical Paper
2014-01-2870
Yuan Fang, Tong Zhang
Abstract Because of the vehicle market competitive and of the raise of customers' demanding, NVH performance became an important job, especially for new energy vehicles. As the electric vehicle moving into the direction of high speed and large torque, electric vehicle vibration and noise problems highlighted gradually. In recent years, CAE has played an increasing role in the design, development and optimization of powertrain NVH at component and system levels. The subject of this paper was the numerical and experimental evaluation of the electromagnetic and vibro-acoustic behavior of an electric powertrain. For this purpose, a coupled and fully flexible dynamics model of the electric powertrain was developed. Then electromagnetic forces including both radial and tangential force and gear mesh excitations including time-varying meshing stiffness, meshing error and meshing impact were computed, which were used to perform forced response analysis on the full FE mesh of the powertrain housing.
2014-10-13
Technical Paper
2014-01-2863
Jouji Kimura, Shinichiro Kobayashi, Katsuhiro Hoshina, Kousuke Kawase, Koji Matsui, Atsushi Yamamoto
Abstract This paper describes the characteristics and mechanism of crankshaft impact noise that radiates from the cylinder body at full load medium engine speeds, based on the mechanism for axial vibration of crankshaft coupled with torsional vibration of crankshaft.
2014-10-13
Technical Paper
2014-01-2849
Wei Guo, Henry Guo, Xiaowei Du, Daniel Wang
Turbochargers are widely used to boost internal combustion engines for both on and off high way applications to meet emission and performance requirements. Due to the high operating temperature, turbochargers are subjected to hostile environment. Low vibration level is one of the key requirements while designing turbo for every application. An engine bracket is employed to support turbine housing to reduce total vibration level. Turbine housing in the turbocharger is commonly equipped with boss to accommodate the engine bracket supporting which eventually includes additional constraints in the turbocharger system. Additional constraints in the turbine housing can lead to adverse impact in the Thermo-Mechanical Fatigue (TMF) life of the housing component. Boss generally has critical influence to thermal stress distribution of the turbine housing. Bad design of boss location could bring severe thermal cracking and surface fracture that leads to loss of functionality and serious accident.
2014-10-13
Technical Paper
2014-01-2864
Daniela Siano, Fabio Bozza, Luigi Teodosio, Vincenzo De Bellis
This paper reports 1D and 3D CFD analyses aiming to improve the gas-dynamic noise emission of a downsized turbocharged VVA engine through the re-design of the intake air-box device, consisting in the introduction of external or internal resonators. Nowadays, modern spark-ignition (SI) engines show more and more complex architectures that, while improving the brake specific fuel consumption (BSFC), may be responsible for the increased noise radiation at the engine intake mouth. In particular VVA systems allow for the actuation of advanced valve strategies that provide a reduction in the BSFC at part load operations thanks to the intake line de-throttling. In these conditions, due to a less effective attenuation of the pressure waves that travel along the intake system, VVA engines produce higher gas-dynamic noise levels. The worsening of the engine gas-dynamic performance can be compensated with a partial re-design of the air-box device, without significantly penalizing the engine power output.
2014-10-13
Technical Paper
2014-01-2676
Takayuki Fuyuto, Masahiro Taki, Reiko Ueda, Yoshiaki Hattori, Hiroshi Kuzuyama, Tsutomu Umehara
Abstract An author's previous studies addressed a combustion system which reduces emissions, noise, and fuel consumption by using PCCI with the split injection of fuel. This concept relies on the premixed combustion of the first injected fuel and accelerated oxidation by the second injected fuel. Although this combustion system requires the optimization of the timing of the second injection, the details of how noise and emissions are reduced have not been elucidated. In this paper, the authors explain the mechanism whereby emissions and noise are reduced by the second injection. In-cylinder visualizations and numerical simulations both showed an increase in smoke and CO as the second injection timing was advanced, as induced by the inhibited oxidation of the rich flame. When the second injection timing is excessively retarded, the amount of soot forming around the near-nozzle increased. The second fuel injection at the optimum timing can mix with the air in the inner-region of the cavity, such that no soot is formed in the near-nozzle region.
2014-10-13
Technical Paper
2014-01-2862
Georg Johann Meingaßner, Hermann Pflaum, Karsten Stahl
Downsizing and downspeeding are currently important development approaches of the automobile industry to improve fuel efficiency and to reduce emissions. Decreased operational speeds in combination with higher combustion pressures lead to an increase of the excitation of torsional vibrations by the combustion engine. Torsional vibrations in powertrains can cause strength and NVH problems as well as lower driving comfort and reliability of the vehicle. Currently, conventional systems for reduction of torsional vibrations are increasingly reaching their limits. In cooperation with several institutes of the Technische Universität München (TUM) innovative concepts for an improved reduction of torsional vibrations in automotive powertrains have been developed. Several of those concepts have been realized as prototype assemblies engineered by the Gear Research Centre (FZG). ([6], [7], [8], [12], [13], [14]) During the design process, different challenges with regard to mass, mass moment of inertia and space demands have to be considered to ensure system performance and to meet vehicle-related requirements.
2014-10-02
Article
The U. S Department of Transportation/NHTSA Vehicle Research and Test Center has commissioned dSPACE to supply an in-lab GPS simulation system. GPS simulation is used in the development and testing of numerous intelligent driving and traffic systems, including collision avoidance, advanced driver-assistance systems, navigation, and V2X communications.
2014-10-01
Technical Paper
2014-01-9029
Uday Nayak, S Aravind, Sunil Aundhekar
Abstract The present competitive market scenario and customer requirements demand for improved NVH quality and to meet statutory norms without increased cost. When gears are used for power transmission, gear noise is of particular concern. The noise may be created due to harmonics of the rotating and meshing internal components. This has a significant effect on the overall vehicle sound quality. Various factors contribute to gearbox noise. Some of them include shaft misalignments, gear geometry, lubrication, bearings and loose mountings. Hence it is essential to study which factors contribute to the gearbox noise and to develop countermeasures for the same. Although a number of factors may contribute to gear noise as mentioned, the scope of this paper is limited to the effect of gear geometry alone on the gearbox noise. This paper offers an experimental investigation of reducing the noise levels in Ashok Leyland gearbox by modifying the gear tooth profile on one of the gear trains in order to meet the futuristic noise statutory norms.
2014-09-30
Article
The Model T261 series rotary transformer coupled torque sensors from SensorData Technologies meet the demanding in-line testing requirements of small motors, pumps, compressors, turbines, fans, and other fractional horsepower rated devices.
2014-09-30
Technical Paper
2014-01-2316
Masahiro Akei, Takayuki Koizumi, Nobutaka Tsujiuchi, Takayuki Yamauchi
Abstract This paper describes a prediction of vibration and the transfer path analysis (TPA) using an engine multi body dynamics (MBD) model and measured frequency response functions (FRFs). TPA is used in order to analyze each contribution of vibration transfer paths. In the TPA, input forces from vibration source to passive part should be identified accurately. In the traditional TPA, an identification of input forces is done using only experimental results. Therefore, a parametric study to an improvement of a structure or an isolation system is impossible. In this study, the MBD model of engine is constructed, and input forces from engine to mainframe of agriculture machine are predicted. The accuracy of prediction is confirmed, compared with the results from the traditional TPA method. The contribution of each transfer path is analyzed, and the vibration levels of operator position are predicted using the measured FRFs and the simulated input forces. As a result, the input forces and the vibration levels of operator position can be predicted accurately.
2014-09-30
Technical Paper
2014-01-2317
Rahul Ramola, G Senthilkumar, P Kannan, Muralidharan Chennakrishnan
Abstract The demand for comfort level in commercial vehicles is steadily increasing. Hence, fine-tuned performance parameters and attributes are required to fulfill the expectations from these vehicles. Refinement of noise and vibration without affecting performances of sub-systems and components has become extremely challenging with increasing customer requirements. This paper presents an approach to identify and reduce the high level whistling noise that was perceived in the passenger compartment while the vehicle was accelerated above 50 kmph. Interior noise measurements in static engine run-up condition reveal that the whistling noise is of specific order. Since, whistling noise is related to aerodynamic response of components, engine cooling fan, turbo charger, alternators and compressors were suspected. Using order tracking and near field measurements, HVAC alternator was confirmed as the main cause for whistling noise. Noise measurements confirmed that orders related to alternator cooling fan became dominant above 50 kmph.
2014-09-30
Technical Paper
2014-01-2318
Masahiro Akei, Takayuki Koizumi, Nobutaka Tsujiuchi, Takayuki Yamauchi
Abstract This paper describes an identification of a sound source model for a diesel engine installed on an agricultural machine by Inverse-Numerical Acoustic analysis (INA), and the applicability of the identified sound source model. INA is a method to identify surface vibrations from surrounding sound pressures. This method is applicable for a complicated-shaped sound source like an engine. In order to confirm the accuracy of the identified sound source model, the surface vibrations of the engine are compared with the measured results. Moreover, in the condition of the simulated engine room, the surrounding sound pressure levels of the engine are predicted using the sound source model and the boundary element method (BEM). For the verification of the prediction accuracy, the surrounding sound pressures of the engine are measured using the testing device which simulated actual engine room, namely an enclosure. As a result, the sound source model of the diesel engine is identified accurately using the INA.
2014-09-30
Technical Paper
2014-01-2315
John Anderson
Abstract This paper describes the development and testing of a Dynamic Vibration Absorber to reduce frame beaming vibration in a highway tractor. Frame beaming occurs when the first vertical bending mode of the frame is excited by road or wheel-end inputs. It is primarily a problem for driver comfort. Up until now, few options were available to resolve this problem. The paper will review the phenomenon, design factors affecting a vehicle's sensitivity to frame beaming, and the principles of Dynamic Vibration Absorbers (AKA Tuned Mass Dampers). Finally, the paper will describe simulation and testing that led to the development of an effective vibration absorber as a field fix.
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