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Viewing 1 to 30 of 49057
2011-05-17
Technical Paper
2011-01-1644
Greg Uhlenhake, Ahmet Selamet, Kevin Fogarty, Kevin Tallio, Philip Keller
A cold turbocharger test facility was designed and developed at The Ohio State University to measure the performance characteristics under steady state operating conditions, investigate unsteady surge, and acquire acoustic data. A specific turbocharger is used for a thermodynamic analysis to determine the capabilities and limitations of the facility, as well as for the design and construction of the screw compressor, flow control, oil, and compression systems. Two different compression system geometries were incorporated. One system allows compressor performance measurements left of the surge line, while the other incorporates a variable-volume plenum. At the full plenum volume and a specific impeller tip speed, the temporal variation of the compressor inlet and outlet and the plenum pressures as well as the turbocharger speed is presented for stable, mild surge, and deep surge operating points.
2011-05-17
Technical Paper
2011-01-1659
Michael Albright, Kurt Veggeberg
A powered seat adjuster is a complex mass-produced assembly that is heavily optimized for low cost and light weight. The consequence is an inevitable degree of uncontrolled variation in components, subassemblies, and final product. Automakers are driving an exceptional focus on quality and the showroom experience of the car buyer is paramount. Therefore, any seat adjuster with the potential to not satisfy the customer's expectation is likely to be screened on the production line. This paper describes NVH metric design in the context of automated production line detection of seat adjuster defects. A key requirement of the production environment is that the metrics offer intuitive explanations of possible defects and are based on industry-standard formulations. The metric set is a hybrid of objective and subjective parameters with a focus on ensuring a robust sorting process that maximizes detection while minimizing the possibility of failing acceptable product.
2011-05-17
Technical Paper
2011-01-1621
Frank Friedrich
While the microcellular urethane is widely known in the automotive industry for its use in jounce bumpers, its use in Noise Vibration Harshness (NVH) applications is often not as well recognized. Even though there are some NVH parts in the market, rubber still dominates it. The objective of this paper is to demonstrate the material properties of MCU and their relevance for NVH applications in chassis and suspension components. It will also demonstrate the importance of package design to suit the use of the MCU material. This is especially important to not only achieve the best performance but also keep overall cost and weight under control. Several application types will be introduced with general design suggestions. A detailed design guideline for these applications is not part of this paper. Each application has a large variety of parameters to be considered in the design. They need to be selectively applied based on customer performance targets.
2011-05-17
Technical Paper
2011-01-1623
Alan V. Parrett, Chong Wang, Xiandi Zeng, David Nielubowicz, Mark Snowden, Jonathon H. Alexander, Ronald Gerdes, Bill Leeder, Charles Zupan
In recent years several variants of lightweight multi-layered acoustic treatments have been used successfully in vehicles to replace conventional barrier-decoupler interior dash mats. The principle involved is to utilize increased acoustic absorption to offset the decrease in insertion loss from the reduced mass such that equivalent vehicle level performance can be achieved. Typical dual density fibrous constructions consist of a relatively dense cap layer on top of a lofted layer. The density and flow resistivity of these layers are tuned to optimize a balance of insertion loss and absorption performance. Generally these have been found to be very effective with the exception of dash mats with very high insertion loss requirements. This paper describes an alternative treatment which consists of a micro-perforated film top layer and fibrous decoupler layer.
2011-05-17
Technical Paper
2011-01-1615
Darius Kurniawan, Eric Rogers
Doors inside an automotive HVAC module are essential components to ensure occupant comfort by controlling the cabin temperature and directing the air flow. For temperature control, the function of a door is not only to close/block the airflow path via the door seal that presses against HVAC wall, but also control the amount of hot and cold airflow to maintain cabin temperature. To meet the stringent OEM sealing requirement while maintaining a cost-effective product, a “V-Shape” soft rubber seal is commonly used. However, in certain conditions when the door is in the position other than closed which creates a small gap, this “V-Shape” seal is susceptible to the generation of objectionable whistle noise for the vehicle passengers. This nuisance can easily reduce end-customer satisfaction to the overall HVAC performance.
2011-05-17
Technical Paper
2011-01-1628
Hejie Lin, Turgay Bengisu, Zissimos Mourelatos
Styrene-Butadiene Rubber (SBR), a copolymer of butadiene and styrene, is widely used in the automotive industry due to its high durability and resistance to abrasion, oils and oxidation. Some of the common applications include tires, vibration isolators, and gaskets, among others. This paper characterizes the dynamic behavior of SBR and discusses the suitability of a visco-elastic model of elastomers, known as the Kelvin model, from a mathematical and physical point of view. An optimization algorithm is used to estimate the parameters of the Kelvin model. The resulting model was shown to produce reasonable approximations of measured dynamic stiffness. The model was also used to calculate the self heating of the elastomer due to energy dissipation by the viscous damping components in the model. Developing such a predictive capability is essential in understanding the dynamic behavior of elastomers considering that their dynamic stiffness can in general depend on temperature.
2011-05-17
Technical Paper
2011-01-1629
Saurabh Suresh, Jeff Kastner, Teik Lim
Reduction of noise transmitted through laminated glass with interlayer is of interest to vehicle applications. Altering the structure of the interlayer can impact sound transmission loss particularly at the coincidence frequency. This study investigates the feasibility of including a porous layer within the laminated glass to act as an acoustic damper. To understand the underlying physics controlling transmission loss in laminated glass design, an approach utilizing transfer matrices is used for modeling each layer in the laminated glass. These transfer matrices are used to relate the acoustic characteristics of two points within a layer. For any two layers in contact, an interface matrix is defined that relates the acoustic fields of the layers depending on their individual characteristics. The solid layer is modeled as an elastic element and the sound propagation through the porous materials is described using the Biot theory.
2011-05-17
Technical Paper
2011-01-1632
Ion Pelinescu, Andrew Christie
One of the most effective NVH solutions used in the automotive industry to reduce structure-borne noise is to apply vibration damping treatments to the vehicle structure. These damping treatments need to meet increasing weight reduction targets, while offering the same or better damping properties. While Liquid Applied Structural Dampers (LASD) are now delivering high damping performance at lower densities, traditional damping measuring techniques are falling short in describing the performance of these extensional layers when applied onto more realistic test samples or real structures. This paper discusses the damping performance of LASD technology, in particular the newer generations of acrylic-based waterborne LASD materials, which through improvements in polymer architecture are achieving increased damping efficiencies together with reduced density.
2011-05-17
Technical Paper
2011-01-1624
Prasanth B, Sachin Wagh, David Hudson
Baffle plates with heat reactive expandable foam sealants have increasingly found their applications in automotives. They are used to separate body cavities and to impede noise, water and dust propagation inside of body cavities, thus control noise intrusion into the passenger compartment. Use of these sealant materials has grown significantly as the demands to improve vehicle acoustic performance has increased. Traditionally quantification of the acoustic performance of expandable baffle samples involved making separate vehicles with and without expandable baffles and measure the incab noise to know the effect. The absolute acoustic evaluation of the baffles is very difficult as number of other vehicle parameters is also responsible for vehicle incab noise. Also, it is a time consuming and a costly method to evaluate.
2011-05-17
Technical Paper
2011-01-1625
John G. Cherng, Qian Xi, Pravansu Mohanty, Gordon Ebbitt
Acoustical materials are widely used in automotive vehicles and other industrial applications. Two important parameters namely Sound Transmission Loss (STL) and absorption coefficient are commonly used to evaluate the acoustical performance of these materials. Other parameters, such as insertion loss, noise reduction, and loss factors are also used to judge their performance depending on the application of these materials. A systematic comparative study of STL and absorption coefficient was conducted on various porous acoustical materials. Several dozen materials including needled cotton fiber (shoddy) and foam materials with or without barrier/scrim were investigated. The results of STL and absorption coefficient are presented and compared. As expected, it was found that most of materials are either good in STL or good in absorption. However, some combinations can achieve a balance of performance in both categories.
2011-05-17
Technical Paper
2011-01-1626
Jonathan Alexander, David Reed, Ronald Gerdes
Flat, constant thickness composites that consisted of a microperforated top layer plus a fibrous decoupler layer were tested for random absorption and transmission loss (TL) performance. The top, microperforated layer consisted of a relatively thick film that contained small, precise micro-perforations. For reference, top layers that consisted of a resistive scrim and an impervious film were also included in this study. Two fibrous materials of constant thickness were used for the decoupler layer between a steel panel and the top microperforated film. The composites' absorption and TL performance were also modeled using the well-known transfer matrix method. This method has been implemented in a commercially available statistical energy analysis (SEA) software package. A comparison of testing and modeling results showed reasonable agreement for absorption results and even better agreement for transmission loss and insertion loss results.
2011-05-17
Journal Article
2011-01-1627
J. Liu, D. W. Herrin
Microperforated panel (MPP) absorbers are rugged, non-combustible, and do not deteriorate over time. That being the case, they are especially suitable for long term use in harsh environments. However, the acoustic performance is modified when contaminated by dust, dirt, or fluids (i.e. oil, water). This paper examines that effect experimentally and correlates the absorption performance with Maa's theory for micro-perforated panels. Transfer impedance and absorption coefficient are measured for different levels of aluminum oxide and carbon dust accumulation. The amount of dust contamination is quantified by measuring the luminance difference between clean and dirty panels with a light meter. The porosity and hole diameter in Maa's equation are modified to account for dust obstruction. The effect of coating the MPP with oil, water, and other appropriate viscous fluids was also measured. This effect was simulated by modifying the viscous factor in Maa's equation.
2011-05-17
Technical Paper
2011-01-1634
Michael Dinsmore, Richard Bliton, Scott Perz
Using advanced, multi-layer poro-elastic acoustical material modeling technologies, an example of acoustical performance optimization of an underhood sound absorber application is presented. In this case, a porous facing in combination with a fibrous sound absorber pad is optimized for maximum efficiency, which allows for dramatic reduction in pad density and weight. Overall sound absorption performance is shown to be equal or improved versus frequency relative to the incumbent design.
2011-05-17
Technical Paper
2011-01-1637
Ahad Khezerloo, Amin owhadi Esfahani PhD, Sina Jalily lng
One of important problems in railway transportation systems is control of noise and vibration. Metal foams are very good medias for absorbing noise. So in this paper, noise of motion of a train is simulated by MATLAB software and the reduction of noise level in a compartment of passenger car that is equipped by metal foam sheets is considered. Commonly, the sound absorption coefficients are obtained experimentally and they are available in datasheets and references. The different parameters that influence on the capability of this equipment were considered. For example the microstructure, thickness, magnitude of compaction, relative density and etc of metal foam is effective parameters. High porosity has good effect on the performance of absorber sheet. By increasing of compaction ratio, in frequency domain we will have enhancing of absorption of the noise. Compaction process is done by two different ways: one is direct and else is progressively.
2011-05-17
Journal Article
2011-01-1575
John David Fieldhouse, David Bryant, Chris John Talbot
Thermo-elastic and thermo-plastic behaviour takes place with a disc brake during heavy braking and it is this aspect of braking that this paper considers. The work is concerned with working towards developing design advice that provides uniform heating of the disc, and equally important, even dissipation of heat from the disc blade. The material presented emanates from a combination of modeling, on-vehicle testing but mainly laboratory observations and subsequent investigations. The experimental work makes use of a purpose built high speed brake dynamometer which incorporates the full vehicle suspension for controlled simulation of the brake and vehicle operating conditions. Advanced instrumentation allows dynamic measurement of brake pressure fluctuations, disc surface temperature and discrete vibration measurements.
2011-05-17
Technical Paper
2011-01-1592
Ashish Tiwari, Maneesh Arora, Ravi Kumar, David Hudson
Comfortable cabin environment from temperature, noise and vibration point of view is one of the most desirable aspects of any vehicle operating in hot or cold environment. Noise generated from HVAC system is one of the most irritating phenomena resulting in customer dissatisfaction and complaints. It becomes absolutely necessary to have low HVAC noise levels when the target market has hot weather all round the year. Balance between control of temperature in desired way with least possible noise and vibration is the key for HVAC performance optimization within constrains posed by design and cost. This paper describes the approach for NVH refinement of front HVAC system proposed for a vehicle with limited off-road capability for which packaging constraints and late changes related to airflow and HVAC unit design for meeting comfort and crash requirements resulted in deterioration of noise and vibrations while operation.
2011-04-12
Journal Article
2011-01-1384
Michael J. Tess, Chang-Wook Lee, Rolf D. Reitz
Several diffusion combustion scaling models were experimentally tested in two geometrically similar single-cylinder diesel engines with a bore diameter ratio of 1.7. Assuming that the engines have the same in-cylinder thermodynamic conditions and equivalence ratio, the combustion models primarily change the fuel injection pressure and engine speed in order to attain similar performance and emissions. The models tested include an extended scaling model, which scales diffusion flame lift-off length and jet spray penetration; a simple scaling model, which only scales spray penetration at equal mean piston speed; and a same speed scaling model, which holds crankshaft rotational velocity constant while also scaling spray penetration. Successfully scaling diffusion combustion proved difficult to accomplish because of apparent differences that remained in the fuel-air mixing and heat transfer processes.
2011-04-12
Technical Paper
2011-01-1391
Philipp Adomeit, Markus Jakob, Andreas Kolbeck, Stefan Pischinger
The requirement of reducing worldwide CO₂ emissions and engine pollutants are demanding an increased use of bio-fuels. Ethanol with its established production technology can contribute to this goal. However, due to its resistive auto-ignition behavior the use of ethanol-based fuels is limited to the spark-ignited gasoline combustion process. For application to the compression-ignited diesel combustion process advanced ignition systems are required. In general, ethanol offers a significant potential to improve the soot emission behavior of the diesel engine due to its oxygen content and its enhanced evaporation behavior. In this contribution the ignition behavior of ethanol and mixtures with high ethanol content is investigated in combination with advanced ignition systems with ceramic glow-plugs under diesel engine relevant thermodynamic conditions in a high pressure and temperature vessel.
2011-04-12
Journal Article
2011-01-1401
Yoolkoo Kim, Hyundal Park, Jeong Uk An, Tae-Suek Kan, Joonsung Park
Various polymer-based coatings are applied on piston skirt to reduce friction loss between the piston skirt and cylinder bore which is one of main factors of energy loss in an automotive engine system. These coatings generally consist of polymer binder (PAI) and solid lubricants (graphite or MoS₂) for low friction property. On the other hand, the present study found that PTFE as a solid lubricant and nano diamond as hard particles can be used to improve the low friction and wear resistance simultaneously. In the process of producing coating material, diamond particles pulverized to a nano size tend to agglomerate. To prevent this, silane (silicon coupling agent) treatment was applied. The inorganic functional groups of silane are attached to the nano diamond surface, which keep the diamond particles are apart.
2011-04-12
Technical Paper
2011-01-1414
Ferdinando Taglialatela-Scafati, Nicola Cesario, Mario Lavorgna, Ezio Mancaruso, Bianca Maria Vaglieco
Increasing demands on emissions reduction and efficiency encouraged a progressive introduction of cleaner combustion concepts. "Advanced" diesel combustions offer a high potential for simultaneous reduction of both NOx and soot within the engine through high inlet charge dilution and mixture homogenization. However, the potential benefits of these combustions in terms of emissions are counterbalanced by their high sensitivity to in-cylinder thermodynamic conditions. This sensitivity makes the engines require closed loop combustion control with real-time information about combustion quality. The parameter widely considered as the most important for the evaluation of the combustion quality in internal combustion engines is the cylinder pressure. However, this kind of measure involves an intrusive approach to the cylinder, expensive sensors and a special mounting process.
2011-05-17
Technical Paper
2011-01-1724
Juliette Florentin, Francois Durieux, Yukihisa Kuriyama, Toyoki Yamamoto
The present work attempts a complete noise and vibration analysis for an electric vehicle at concept stage. The candidate vehicle is the Future Steel Vehicle (FSV), a lightweight steel body with an electric motor developed by WorldAutoSteel [1,2,3]. Measurements were conducted on two small Mitsubishi vehicles that both share the same body, yet one is equipped with an internal combustion engine and the other with an electric motor. The outcome was used as a starting point to identify assets and pitfalls of electric motor noise and draw a set of Noise Vibration and Harshness (NVH) targets for FSV. Compared to a combustion engine, the electric motor shows significantly lower sound pressure levels, except for an isolated high frequency peak heard at high speeds (3500 Hz when the vehicle drives at top speed). The prominence of this peak is lowered by increased use of acoustic absorbent materials in the motor compartment.
2011-05-17
Journal Article
2011-01-1693
Luca Guj, Theophane Courtois, Claudio Bertolini
Typically, in the automotive industry, the design of the body damping treatment package with respect to NVH targets is carried out in such a way to achieve panel mobility targets, within given weight and cost constraints. Vibration mobility reduction can be efficiently achieved thanks to dedicated CAE FE tools, which can take into account the properties of damping composites, and also, which can provide their optimal location on the body structure, for a minimal added mass and a maximized efficiency. This need has led to the development of different numerical design and optimization strategies, all based on the modeling of the damping composites by mean of equivalent shell representations, which is a versatile solution for the full vehicle simulation with various damping layouts.
2011-05-17
Technical Paper
2011-01-1686
Oliver Jung, Volker Grützmacher
The description of subjectively perceived acoustical comfort inside vehicle compartments is a complex challenge. On the one hand, it depends on physically measurable events like acoustical stimuli with a defined sound pressure level and frequency distribution. On the other hand, it is also strongly dependent on further factors like the customer's individual expectations, the previously made experiences and other contextual influences. Furthermore, many different driving conditions have to be considered for a customer-related assessment of driving comfort. In this paper, the mechanisms of acoustical comfort inside vehicle compartments are described on basis of various measurements, listening tests and qualitative assessments. The acoustical properties of driving noises at various driving conditions were taken into account as well as room-acoustical parameters of vehicle interiors and factors of speech communication between passengers.
2011-05-17
Technical Paper
2011-01-1719
Chong Wang, Sejoong Oh, Qijun Zhang, Kurt Schneider
In traditional FE based structure-borne noise analysis, interior trims are normally modeled as lump masses in the FE structure model and acoustic specific impedance of the trim is assigned to the FE acoustics model when necessary. This simplification has proven to be effective and sufficient for low frequency analysis. However, as the frequency goes into the mid-frequency range, the elastic behavior of the trim may impose some effects on the structural and acoustic responses. The approach described in this paper is based on the structural FE and acoustic SEA coupling analysis developed by ESI, aiming to improve the modeling efficiency for a possible quick turnaround in virtual assessments.
2011-08-30
Journal Article
2011-01-2111
Nobuo Ushioda, Yasuhiro Ogasawara
Fuel economy is one of the most essential performance requirements for Passenger Car Motor Oil because of fuel economy regulations in many countries and increasing fuel prices. The ILSAC GF-5 specification was issued on December 22, 2009 and requires better fuel economy performance based on the Sequence VID (Seq. VID) Test and higher weighted piston deposit merits based on the Sequence IIIG Test, compared to the ILSAC GF-4 specification. Fuel economy performance is affected by viscosity, friction modification and the lubricant additive chemistries. However, fuel economy engine tests under combustion mode introduce high variability into a fuel economy measurement. Screening by bench testing is complicated by the difficulty to reproduce friction conditions of all of engine parts. A motored friction torque test using an engine is one of the better solutions for fuel economy screening.
2011-08-30
Technical Paper
2011-01-2113
Masataka Hashimoto, Tadanori Azuma, Morio Sumimoto, Kanji Mitsuda
A new type of lube oil cleaning system is successfully developed for semi-permanent use of oil by always keeping oil clean with the result of no oil change and no waste oil. It is in practical use in many marine diesel engines and in some other fields. In recent years, possibility of semi-permanent use of engines themselves has been expected based on the field data. A ship test for 7 years has verified the expected semi-permanent use of engines with almost no wear and constant thermal efficiency during the test. We present the characteristics of the oil cleaning system and the result of the test. Also, a new type of fuel oil cleaning system is presented which is useful for cleaning low quality fuel oil. As a whole, this test is the beginning of the new stage of our work following the semi-permanent use of lube oil, which has been verified and established in many diesel engines since the 1980s.
2011-08-30
Journal Article
2011-01-2114
Jai G. Bansal, Patrick Colby, Maryann Devine, Jack Emert, Kaustav Sinha
This paper is first in a series of papers designed to investigate wear processes in modern heavy duty diesel engines. The objective of the series is to discuss the effects that engine drive cycle, lubricant formulations and in-service ageing of lubricants have on wear of critical engine components. In this paper, the Radioactive Tracer Technology technique was used to study the steady state wear behavior of a number of contacting surfaces in a Caterpillar 1P engine, as a function of the drive cycle. A test protocol consisting of 7 modes or stages was used to simulate a variety of drive cycles. The results from this work provide useful insights into the wear behavior of these surfaces under a variety of speed and load conditions.
2011-08-30
Technical Paper
2011-01-2110
Farzan Parsinejad, Wilton Biggs
The delicate balance between global supply and demand for energy, in conjunction with environmental concerns related to burning fossil fuels, have resulted in vehicle designs that stress higher fuel economy. Among new engine designs is Direct Injection Spark Ignition, or DISI, which employs a more precise fuel metering system and is designed for combustion at higher compression ratios than Port Fuel Injection (PFI) engines. As a result, the performance of DISI engines can easily be altered by the presence of carbonaceous deposits on intake valves and in the combustion chamber. In this study, the characteristics of these deposits have been investigated using elemental and thermal analytical techniques. Deposits from intake valves and combustion chambers have been collected from various DISI engines (both older and more modern ones).
2011-08-30
Technical Paper
2011-01-2030
Takuji Murayama
The continuously variable transmission (CVT) with a rubber belt used in scooters is also regarded as a potential automatic transmission mechanism for conventional motorcycles. By making this system more compact and building it into the engine, a motorcycle CVT engine has been developed that is about the same size as a manual transmission (MT) engine. During driving with a CVT, heat is generated by friction at the sheaves, and therefore it was necessary to secure a certain length of belt to ensure that external air flows efficiently to the sheaves. However, making the CVT more compact restricted the belt length, which decreased cooling performance and increased the number of bends in the belt, making it difficult to maintain durability. To address this issue, a plastic resin drive belt and newly designed sheaves were adopted, and durability of more than that of a scooter was achieved.
2011-08-30
Journal Article
2011-01-2029
Atsushi Tanaka, Hiroki Shimada, Naoki Hiraiwa, Tsuyoshi Arai, Hideki Asano, Yasuhiro Nishikawa
The need to improve fuel consumption by saving the weights of automobile parts is growing from the viewpoint of global warming mitigation. In the case of a throttle body for controlling the air flow volume into an engine, it is important to achieve a high dimensional accuracy of the valve-bore gap in the state of closed valve. In fact, most throttle bodies are made of precision-machined metal. Therefore, resin throttle bodies are drawing attention as a lightweight alternate. However, in comparison with metal throttle bodies, resin throttle bodies have two potential disadvantages that should be solved prior to productization. The first one is greater air leakage in the state of closed valve, and the second one is smaller heat conduction for unfreezing the valve in a frigid climate. We have developed an electronic resin throttle body that has overcome the above-mentioned disadvantages.
Viewing 1 to 30 of 49057

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