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Viewing 241 to 270 of 36624
2009-01-21
Technical Paper
2009-26-0025
Thomas Körfer, Matthias Lamping, Andreas Kolbeck, Stefan Pischinger, Dirk Adolph, Hartwig Busch
The high-speed Dl-diesel engine has made a significant advance since the beginning of the 90's in the Western European passenger car market. Apart from the traditional advantage in fuel economy, further factors contributing to this success have been significantly improved performance and power density, as well as the permanent progress made in acoustics and comfort. In addition to the efforts to improve efficiency of automotive powertrains, the requirement for cleaner air increases through the continuous worldwide restriction of emissions by legislative regulations for diesel engines. Against the backdrop of global climate change, significant reduction of CO2 is observed. Hence, for the future, engine and vehicle concepts are needed, that, while maintaining the well-established attractive market attributes, compare more favorably with regard to fuel consumption.
2009-01-21
Technical Paper
2009-26-0027
Juttu S., Thipse S.S, Marathe N.V., Gajendra Babu M.K., Öivind Andersson
The exact shape of the combustion chamber will not have a major effect in case of homogeneous type of combustion. However, presently engine needs to be operated in diesel mode during start-up and outside HCCI operating range to meet stringent emission norms. Hence, the combustion chamber is therefore optimized for conventional diesel mode operation for minimum emissions as well as benefit to HCCI mode operation with better swirl. When operated in pure HCCI mode, the exact shape of the combustion chamber is of little relevance-mainly because the fuel jets do not interact with the bowl at early injection conditions. However, at some operating conditions it is necessary to operate with partially premixed conditions where fuel is injected between 20 to 30° BTDC. Then bowl geometry plays significant role to promote homogeneous mixture of air and fuel. There is no need for late cycle turbulence generation in HCCI mode, since it is not a mixing controlled process.
2009-01-21
Technical Paper
2009-26-0017
C, Paz, J. Porteiro, A. Eirís, E. Suárez, A. Sánchez, C. Castaño
Future NOx emissions limits are very difficult to meet with conventional high pressure EGR loop. This limitation causes diesel engine manufacturers to give much more attention to low pressure EGR systems. This configuration enables higher EGR flow rates and therefore lower NOx emissions at the same engine operation conditions. The implementation of low pressure loop ensures sufficient driving pressure for the EGR flow rate however conventional compressors are not specifically designed to endure the fouling of Diesel exhausts. An improved version known as clean low pressure loop takes the EGR source downstream of the diesel particulate filter keeping the compressor free of soot. The performance of the compressor improves substantially but it is necessary to protect it from eventual ceramic particles that can be discarded from the DPF.
2009-01-21
Technical Paper
2009-26-0020
K. C. Vora, S. S. Ramdasi, N. H. Walke, A. V Marathe, N. V. Marathe
Considering the growing demand for emission reduction, diesel engines are becoming more and more popular. CO2 can be further reduced by downsizing the engine. Engines in the range of 1.0 to 3.0 liter cubic capacity are being re-designed for high specific power in the range of 50 to 75 kW/l with peak firing pressure in the range of 160 to 200 bar, bsfc below 200 g/kWh and extremely low emissions to meet Euro V Norms and beyond. This paper highlights development strategies employed to meet this enhanced dynamic performance for such compact diesel engines. Some of the areas highlighted are design considerations, high performance crank train, cylinder head and cylinder block to meet high mechanical and thermal loading, air induction with 4 valve technology and VNT/Dual turbochargers, fuel injection with piezo multi stage common rail fuel injection and emission control technology. The use of diesel engine will continue with upward trend worldwide.
2009-01-21
Technical Paper
2009-26-0019
Andy Banks, Phil Carden, Brian Cooper, Kevin Harding, Michael Jeremy, Gareth Strong, Trevor Downes
The demand for downsized lightweight, cost-effective diesel engines will cause the dominance of in-line 4 cylinder configurations to be reviewed. New 3 cylinder engine designs targeting specific ratings of 75 kW/7 and above, with improved NVH characteristics compared to current 4 cylinder engines are under development. This paper will summarize the strengths of the L3 layout when compared with current L4 best-in-class powertrains, and comment upon the L3 design in terms of package, performance, emissions and NVH attributes. A 3-cylinder, low fuel consumption research engine will be highlighted as the potential basis for future application both in the developing and mature marketplace.
2009-01-21
Technical Paper
2009-26-0010
Pinaki Mondal, Bhangale U.D., Balasubramanian N., Dalela S, Sharma G.K., Abhishek Kumar, Varun Aggarwal, Abhnav Kumar
Road safety is becoming a strategic issue for sustainable development of India. Increasing vehicle population and low road density (India has 2.56 km road/thousand population and 768 km road/thousand km2 of total land.) are aggravating the problem. Introduction of modern safety features in small cars are inevitable to improve the safety scenario. Recently Anti-lock Braking System (ABS) has been started to be introduced in low segment family cars. But still the effect of ABS, fitted on these cars, in reducing the road accident are debatable and in-depth studies are required in this field. A thorough investigation of usefulness of ABS on Indian road condition took place in this paper. An instrumented vehicle has been used to study the braking performance of a small family vehicle with ABS ON and OFF condition on two different types of road surfaces, namely dry and wet. In addition to the vehicle performance the focus has been given to the vehicle stability criteria.
2009-01-21
Technical Paper
2009-26-0013
Phil Blakeman, Karl Arnby, Per Marsh, Colin Newman, Gudmund Smedler
This paper describes the development and characterization of a Selective Catalytic Reduction (SCR) catalyst system for EUIV (HDD) engines. The performance of the SCR catalyst and the impact of catalyst volume are described. The effect of using an ammonia slip catalyst behind the SCR catalyst is investigated. The durability of the SCR catalyst is described. Finally, examples of the use of computer modelling to refine the optimum volume and urea injection strategy are given. The results demonstrate how a combination of practical experiments and computer modelling can be used to refine the system and provide a cost-effective exhaust aftertreatment solution.
2011-05-17
Technical Paper
2011-01-1516
Sifa Zheng, ZhongXu Kang, XiaoMin Lian
Different limitations exist in the practical application of one-dimensional and three-dimensional methods on the acoustic simulation of muffler respectively. Thus, a hybrid one/three-dimensional approach is developed in present paper to carry out the acoustic simulation of muffler matching with the engine. The acoustic source characteristics of engine are computed with one-dimensional methods, and acoustic four pole parameters of muffler are computed with three-dimensional methods, respectively. And, the insertion loss of muffler is finally calculated. The insertion loss of a muffler equipped with Selective Catalytic Reduction (SCR) in a heavy duty vehicle is simulated. The numerical results agree well with the experimental results, which verifies the reliability and accuracy of the present approach.
2011-05-17
Technical Paper
2011-01-1519
Morten Nils Lindborg, Mikael Karlsson, Ragnar Glav, Tony Karlsson
Flow reversal chambers are common design elements in mufflers. Here an idealized flow reversal chamber with large cross-section but small depth has been studied. The inlet and outlet ducts as well as the cross-sectional area are fixed while the depth of the chamber can be varied. The resulting systems are then characterized experimentally using the two-microphone wave decomposition method and compared with results from both finite element modeling and various approaches using two-port elements. The finite element modeling results are in excellent agreement with the measurements over the whole frequency range studied, while two-port modeling can be used with engineering precision in the low frequency range. The influence of mean flow was studied experimentally and was shown to have relatively small influence, mainly adding some additional losses at low frequencies.
2011-05-17
Technical Paper
2011-01-1520
ChulMin Park, Jihoon Jeong, Gihwan Kim, Dohyun Kim, Sang-il Lee, Hyunku Lee
The reduction of intake noise is a very important factor in controlling the interior noise levels of vehicles, particularly at low and major engine operating speeds. A vehicle intake system generally consists of air cleaner box, hose, duct, and filter element. Also, resonators and porous duct are included, being used to reduce intake noise. For more accurate estimation of the transmission loss (TL), it seems important to develop a CAE model that accurately describes this system. In this paper, simple methods, which can consider the effects of filter element and vibro-acoustic coupling, are suggested which could remarkably improve estimation accuracy of the TL. The filter element is assumed as equivalent semi-rigid porous materials characterized by the flow resistivity defined by the pressure drop, velocity, and thickness.
2011-05-17
Technical Paper
2011-01-1524
Steven Amphlett, Patrick C. Niven, Francisco Payri, Antonio J. Torregrosa
Acoustics of automotive intake and exhaust systems have been modelled very successfully for many years using 1D gas dynamic simulations. These use pseudo 3D models to allow complex components to be constructed from simple building blocks. In recent years, tools have appeared that automate the construction of network models from 3D geometries of intake and exhaust components. Using these tools, concurrent noise and performance predictions are a core part of most engine development programmes. However, there is still much interest in the more traditional field of linear acoustics: analysing the acoustic behaviour of isolated components or predicting radiated noise using a linear source. Existing approaches break the intake and exhaust system down into a set of components, each with known acoustic properties. They are then connected together to create a network that replicates the donor non-linear model.
2011-05-17
Technical Paper
2011-01-1521
Emel Selamet, Ahmet Selamet, Asim Iqbal, Hyunsu Kim
The effectiveness of the Helmholtz resonator as a narrow band acoustic attenuator, particularly at low frequencies, makes it a highly desirable component in a wide variety of applications, including engine breathing systems. The present study investigates the influence of mean flow grazing over the neck of such a configuration on its acoustic performance both computationally and experimentally. Three-dimensional unsteady, turbulent, and compressible Navier-Stokes equations are solved by using the Pressure-Implicit-Splitting-of-Operators algorithm in STAR-CD to determine the time-dependent flow field. The introduction of mean flow in the main duct is shown to reduce the peak transmission loss and shift the fundamental resonance frequency to a higher value.
2011-05-17
Technical Paper
2011-01-1526
Gianluca Montenegro, Augusto Della Torre, Angelo Onorati, Robert Fairbrother, Andreas Dolinar
The acoustic simulation of internal combustion engine exhaust systems is an important aspect to meet customer expectations and legislation targets. One dimensional gas dynamic simulation tools are used for the calculation of the exhaust orifice noise in the early stages of the engine development process. This includes the prediction of the acoustic performance of individual components in the exhaust line. One common element used in exhaust systems to increase the acoustic damping is the plug flow muffler. This study looks at the prediction of acoustic performance of various plug mufflers at different flow velocities. These include a single plug muffler, a double plug muffler and an eccentric plug muffler with different porosities for the perforated sections. To this purpose a generic 3D cell approach was developed and applied.
2011-04-12
Technical Paper
2011-01-1436
Christopher P. Quigley
Modern vehicle electrical architectures are extremely complex and based on large number of Electronic Control Units (ECUs) integrated with hardwiring or a network technology such as Controller Area Network (CAN), Local Interconnect Network (LIN) or FlexRay. Even a simple system such as a driver's door can contain a large number of control functions such as electric windows, electric mirrors, seat control switches and therefore a lot of internal wiring is required within the door system. To reduce cost, weight and complexity of the wiring harness, it is usual for some combination of CAN, LIN and hardwired connections to be used for electronics integration. The key problem with this is how to assess the potential for cost and weight saving of candidate architectures at the very early stage of the design process and therefore how to choose a particular electrical architecture.
2011-04-12
Technical Paper
2011-01-1438
Johann C. Wurzenberger, Sophie Bardubitzki, Peter Bartsch, Tomaz Katrasnik
Modern Diesel engines require an integrated development of combustion strategies, air management and exhaust aftertreatment. This study presents a comprehensive simulation approach with the aim to support engine development activities in the virtual environment. A real-time capable engine, vehicle and control model is extended by three key features. First, a pollutant production model is embedded in a two-zone cylinder model. Second, a framework for catalytic pollutant conversion is built focusing on modern diesel exhaust aftertreatment systems. Third, an extended species transport model is introduced considering the transport of pollutants through the air path. The entire plant model is validated on the example of a passenger car Diesel engine. The predicted engine behavior is compared with steady-state measurements. The NO formation model is investigated for a series of steady-state and transient operating conditions.
2011-04-12
Technical Paper
2011-01-1439
Christoph Poetsch, Herwig Ofner, Eberhard Schutting
The paper describes a universally structured simulation platform which is used for the analysis and prediction of combustion in compression ignition (CI) engines. The models are on a zero-dimensional crank angle resolved basis as commonly used for engine cycle simulations. This platform represents a kind of thermodynamic framework which can be linked to single and multi zone combustion models. It is mainly used as work environment for the development and testing of new models which thereafter are implemented to other codes. One recent development task focused on a multi zone combustion model which corresponds to the approach of Hiroyasu. This model was taken from literature, extended with additional features described in this paper, and implemented into the thermodynamic simulation platform.
2011-05-17
Journal Article
2011-01-1501
Joseph L. Stout
Idle Combustion Stability has previously been difficult to predict prior to prototype engine development. This paper describes an empirical modeling approach to predicting upfront idle combustion stability. The model outputs are the combustion torque harmonic magnitudes and %LNV. The paper describes the modeling methodology and provides correlation results for different engine configurations.
2011-05-17
Technical Paper
2011-01-1502
Brian K. Wilson, Glen Peterson, Amey Kulkarni, Ashish Kanase
Traditionally, the development of automotive drivelines incorporating hypoid or spiral bevel gearing using Computer Aided Engineering (CAE) methods have included the analysis of gear contact patterns independent of the influence of the flexible members of the driveline such as the housing and shafting. The gear tooth form development typically occurs using various non-linear gear contact solutions available on the market, but the final refinement of the gear itself usually must wait until the actual hardware can be fabricated and tested in the driveline system. This behavior may result in several costly and time consuming iterations of testing, modifying, and re-testing a gearset, since the up-front CAE tools did not account for the flexibility of the driveline system, nor factors such as bearing pre-load effects, thermal growth, driveline torque levels, dynamic modes of the shafting, and many other important factors.
2011-05-17
Technical Paper
2011-01-1504
Limin Zhou, Jiawei Liu, Tim Wu
Discontinuous boundary elements, such as constant elements, have been used in many engineering applications for years. In acoustics, the primary variables are sound pressure and normal particle velocity, and they can be defined at the center of each constant element. Since the acoustic variables do not need to be continuous across the element boundary, it is easy to write an algorithm to automatically refine the mesh by subdividing inside each element as frequency goes up. To take one step further, one may also choose to use a geometrically incompatible mesh, in which not only the primary variables but also the geometrical nodes do not need to be continuous across the element boundary. The main advantage is that a model can be quickly assembled from different sources without paying too much attention to the node-to-node continuity at junctions. As such, it is easy to add or remove a component at will to see its effect at the concept design stage.
2011-05-17
Technical Paper
2011-01-1665
Wade R. Bray
Human hearing, with its active transducers, attention process and remarkable signal-processing abilities, challenges the transportation-product sound quality engineer to measure accordingly and has clearly given rise to the practice and tools of sound quality engineering. Transient events and/or level changes of various durations and magnitudes and over various frequency bandwidths are measurable with due care in the majority of “real-world” acoustic time-signal histories, and frequently carry subjective importance. Inspired by recent work with wind-turbine sound situations, the focus of this paper is to suggest reconsideration of some low-frequency measurement methodologies in the transportation realm.
2011-05-17
Technical Paper
2011-01-1674
Magnus Olsson, Mikael Törmänen, Sylvain Sauvage, Catharina Hansen
In modern vehicles, each system must meet tough demands to fulfill the many different attribute requirements, design constraints and manufacturing limitations. It becomes difficult and time-consuming to find an optimal and robust design using a traditional engineering process. Volvo Cars has for several years been using Multi-Disciplinary Optimization, MDO, that basically shows the customer attributes levels, such as NVH, ride comfort, and driveability as a function of different parameter configurations. This greatly facilitates project team understanding of the limitations and possibilities of the different systems, and has become a key enabler to achieving a good balance between different attributes. Traditionally, this type of comprehensive Design of Experiments (DOE) optimization demands huge time and computer resources. Frequently, experimental designs will not fulfill manufacturing limitations or attribute targets, making this decision process slow, tedious, and fruitless.
2011-08-30
Journal Article
2011-01-1982
Lars Zigan, Markus Ammon, Ingo Schmitz, Michael Wensing, Alfred Leipertz, Vivek Gupta
The influence of fuel composition on sprays was studied in an injection chamber at DISI conditions with late injection timing. Fuels with high, mid and low volatility (n-hexane, n-heptane, n-decane) and a 3-component mixture with similar fuel properties like gasoline were investigated. The injection conditions were chosen to model suppressed or rapid evaporation. Mie scattering imaging and phase Doppler anemometry were used to investigate the liquid spray structure. A spray model was set up applying the CFD-Code OpenFOAM. The atomization was found to be different for n-decane that showed a smaller average droplet size due to viscosity dependence of injected mass. And for evaporating conditions, a stratification of the vapor components in the 3-component fuel spray was observed.
2011-08-30
Technical Paper
2011-01-1941
Kiyoshi Kawasaki, Koji Yamane, Tatsuro Ikawa
This study derives regression equations for predicting the cetane number of biodiesel fuels based on chemical analysis data. For conducting the regression analysis, 34 fuel samples with a wide variety of ignition qualities were made by mixing five kinds of biodiesels and five kinds of fatty acid methyl ester (FAME) reagents. The relationship between the cetane number, measured in a constant-volume combustion chamber, and fuel properties such as iodine value, saponification number, and boiling point, was investigated. Based on the results, four regression equations were proposed and their accuracies were compared. The results show that the regression equation based on fuel composition gives a cetane number with high accuracy, whereas it can be only be approximately predicted from the iodine value.
2011-08-30
Technical Paper
2011-01-1894
Andrei Boiarciuc, Alain Floch
Powerful 1D engine simulation softwares are widely used in the automotive industry to model internal combustion engines. The gas-dynamics exchange process is often well modeled whereas the combustion process is accounted for as a Wiebe function. As the combustion description is a key parameter for engine efficiency evaluation, predictive 0D modeling of heat release seems to be the issue in order to reliably model the cylinder pressure. A 0D phenomenological SI combustion model is proposed in order to predictively describe the heat release rate, this model being developed with Matlab-Simulink and coupled to GT Power. The model is based on eddy burn up approach and takes into account the geometry of the combustion chamber, the turbulent intensity, the RBG effects. As turbulence is a key feature in SI combustion modeling with eddy burn up approach, at this stage of the study turbulent kinetic energy data resulting from 3D CFD computation was employed.
2011-08-30
Journal Article
2011-01-1893
Maria Rivas, Pascal Higelin, Christian Caillol, Olivier Sename, Emmanuel Witrant, Vincent Talon
To improve the prediction of the combustion processes in spark ignition engines, a 0D flame/wall interaction submodel has been developed. A two-zones combustion model is implemented and the designed submodel for the flame/wall interaction is included. The flame/wall interaction phenomenon is conceived as a dimensionless function multiplying the burning rate equation. The submodel considers the cylinder shape and the flame surface that spreads inside the combustion chamber. The designed function represents the influence of the cylinder walls while the flame surface propagates across the cylinder. To determine the validity of the combustion model and the flame/wall interaction submodel, the system was tested using the available measurements on a 2 liter SI engine. The model was validated by comparing simulated cylinder pressure and energy release rate with measurements. A good agreement between the implemented model and the measurements was obtained.
2011-08-30
Technical Paper
2011-01-1892
Atsushi Teraji, Anand Gurupatham
The objective of this work was to improve the accuracy of the combustion speed estimation in rich fuel condition (φ ≻ 1.2) as in case of Gasoline Direct Injection (GDI) engine. During rich fuel mixture combustion, the accuracy of calculation of laminar burning velocity deteriorates due to not considering the flame stretch. In the present study, the unstable flame was formed due to the imbalance of the mass diffusion and the temperature diffusion of the fuel (Lewis Number (Le) ≺1.0) was modeled. The laminar burning speed model was developed by considering the stretch. It was applied with three-dimensional combustion simulation tools together with the Universal Coherent Flamelet Model (UCFM), a flame propagation model. The model has shown the capability to reproduce the heat generation (heat release rate) at high accuracy in comparison with experimental data.
2011-08-30
Technical Paper
2011-01-1897
L. Allocca, M. Costa, A. Montanaro, U. Sorge
Three high pressure multi-hole GDI injectors, one manufactured by Continental, two manufactured by Bosch, are experimentally characterized under various injection strategies in terms of instantaneous mass flow rate and fuel dispersion. Spray visualization within an optically accessible pressure vessel allows the measurement of the single jet cone angle and penetration length. A portable numerical model for the issuing spray dynamics is developed within the AVL Fire code, exploiting a log-normal distribution for the initial droplets diameter, whose expected value and variance are properly defined as a function of the main physical parameters. Tuning of the entering constants is realized by means of an automatic optimization procedure. An example of application of the spray model within a 3D simulation of the in-cylinder process of a GDI engine is presented. Effects of splitting injection into two successive events are discussed.
2011-08-30
Technical Paper
2011-01-1898
G. Alix, C. Pera, J. Bohbot, A. Baldari
Acoustics influence on internal combustion engine volumetric efficiency is obvious and the use of modeling to represent its effect is largely spread. In this regard, LMS has developed a new 1D model library, namely CFD1D, to model engine intake and exhaust lines under LMS Imagine. Lab AMESim platform. Simulations have been performed at IFP Energies nouvelles (IFPEN) to compare duct system modeling with two different approaches: on the one side, with the brand new 1D library and on the other side, with state-of-the-art 0D lumped parameter models (IFP-Engine library under the same platform). This paper aims at comparing 0D and 1D modeling strategies for two naturally-aspirated spark-ignition engines: a single-cylinder propane-fueled engine and a Honda K20A engine with a dedicated intake system used for a cylinder deactivation concept development. For each application, a 0D and a 1D intake system model is realized, based on real engine test-bed geometry.
2011-08-30
Technical Paper
2011-01-1899
Kaushal P. Nishad, Amsini Sadiki, Johannes Janicka
In the present study a LES numerical modeling is carried out for a GDI using KIVA-4 CFD code. Thereby a comprehensive model for the fuel injection process as encountered in IC engine injectors is integrated in a Eulerian-Lagrangian framework. The injector represents a continental piezoinjector with outwardly opening nozzle. The model includes atomization, collision, evaporation and SGS turbulence models. The atomization is described with a combined primary and secondary atomization model. For the primary atomization, a LISA model is used, which is based on the assumption of formation of unstable hollow sheet close to nozzle exit, while a TAB based model is used for the secondary atomization. A new appropriate collision-coalescence model that is independent of mesh size and type is suggested and integrated into the spray model. It accounts for different regimes of droplet-droplet interactions (e.g. bouncing separation, stretching separation, reflective separation and coalescence).
2011-08-30
Technical Paper
2011-01-1846
Satoshi Sakaida, Yutaka Tabe, Takemi Chikahisa
To design diesel engines adapted to future exhaust gas regulation, it would be advantageous to have a driving mode simulation for vehicle performance and exhaust emissions, including after-treatment systems. The combustion model for this objective must be able to simulate the engine performance in very short time. We have tried to develop such diesel engine combustion model by adding the improvements to the Hiroyasu model. In this paper, we detail the improvements that were added to this model and comparisons the calculated results by the improved model with experimental result.
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