Criteria

Text:
Display:

Results

Viewing 1 to 30 of 6230
2010-04-12
Technical Paper
2010-01-0568
Riccardo Ceccarelli, Philippe Moulin, Carlos Canudas de Wit
In nowadays diesel engine, the turbocharger system plays a very important role in the engine functioning and any loss of the turbine efficiency can lead to driveability problems and the increment of emissions. In this paper, a VGT turbocharger fault detection system is proposed. The method is based on a physical model of the turbocharger and includes an estimation of the turbine efficiency by a nonlinear adaptive observer. A sensitivity analysis is provided in order to evaluate the impact of different sensors fault, (drift and bias), used to feed the observer, on the estimation of turbine efficiency error. By the means of this analysis a robust variable threshold is provided in order to reduce false detection alarm. Simulation results, based on co-simulation professional platform (AMEsim© and Simulink©), are provided to validate the strategy.
2010-04-12
Technical Paper
2010-01-0595
Qianwang Fan, Zongjie Hu, Jun Deng, Liguang Li, Yi You, Jingyan Hu
This paper presents the simulation of in-cylinder stratified mixture formation, spray motion, combustion and emissions in a four-stroke and four valves direct injection spark ignition (DISI) engine with a pent-roof combustion chamber by the computational fluid dynamics (CFD) code. The Extended Coherent Flame Combustion Model (ECFM), implemented in the AVL-Fire codes, was employed. The key parameters of spray characteristics related to computing settings, such as skew angle, cone angle and flow per pulse width with experimental measurements were compared. The numerical analysis is mainly focused on how the tumble flow ratio and geometry of piston bowls affect the motion of charge/spray in-cylinder, the formation of stratified mixture and the combustion and emissions (NO and CO₂) for the wall-guided stratified-charge spark-ignition DISI engine.
2010-04-12
Journal Article
2010-01-0585
Paul Whitaker, Yuan Shen, Christian Spanner, Heribert Fuchs, Apoorv Agarwal, Kevin Byrd
Gasoline turbocharged direct injection (GTDI) engines, such as EcoBoost™ from Ford, are becoming established as a high value technology solution to improve passenger car and light truck fuel economy. Due to their high specific performance and excellent low-speed torque, improved fuel economy can be realized due to downsizing and downspeeding without sacrificing performance and driveability while meeting the most stringent future emissions standards with an inexpensive three-way catalyst. A logical and synergistic extension of the EcoBoost™ strategy is the use of E85 (approximately 85% ethanol and 15% gasoline) for knock mitigation. Direct injection of E85 is very effective in suppressing knock due to ethanol's high heat of vaporization - which increases the charge cooling benefit of direct injection - and inherently high octane rating. As a result, higher boost levels can be achieved while maintaining optimal combustion phasing giving high thermal efficiency.
2010-04-12
Journal Article
2010-01-0590
John E. Kirwan, Mark Shost, Gregory Roth, James Zizelman
Today turbo-diesel powertrains offering low fuel consumption and good low-end torque comprise a significant fraction of the light-duty vehicle market in Europe. Global CO₂ regulation and customer fuel prices are expected to continue providing pressure for powertrain fuel efficiency. However, regulated emissions for NO and particulate matter have the potential to further expand the incremental cost of diesel powertrain applications. Vehicle segments with the most cost sensitivity like compacts under 1400 kg weight look for alternatives to meet the CO₂ challenge but maintain an attractive customer offering. In this paper the concepts of downsizing and downspeeding gasoline engines are explored while meeting performance needs through increased BMEP to maintain good driveability and vehicle launch dynamics. A critical enabler for the solution is adoption of gasoline direct injection (GDi) fuel systems.
2010-04-12
Technical Paper
2010-01-0498
Cristiana Delprete, Carlo Rosso, Andrea Vercelli
Thermo-structural analysis of components is usually carried out by means of two FE models, one that solves the thermal problem and one that, using the results of the thermal model, computes strains and stresses. The interaction between the two models is based on the superposition principle, but it means that the mutual effects and the non-linearities between the two physical problems are neglected. In this paper a multiphysics approach based on the Cell Method is proposed and it is applied to a time dependent thermo-mechanical case study represented by an exhaust manifold simulacrum: the coupled thermal and mechanical problems are solved in an unique run, giving the opportunity to take into account mutual effects. Comparing the results with the traditional FE analysis the advantages in terms of accuracy and computational time achieved through the proposed methodology are highlighted.
2011-04-12
Technical Paper
2011-01-0343
Patrick Haenel, Philipp Seyfried, Henning Kleeberg, Dean Tomazic
Downsized direct-injected boosted gasoline engines with high specific power and torque output are leading the way to reduce fuel consumption in passenger car vehicles while maintaining the same performance when compared to applications with larger naturally aspirated engines. These downsized engines reach brake mean effective pressure levels which are in excess of 20 bar. When targeting high output levels at low engine speeds, undesired combustion events called pre-ignition can occur. These pre-ignition events are typically accompanied by very high cylinder peak pressures which can lead to severe damage if the engine is not designed to withstand these high cylinder pressures. Although these pre-ignition events have been reported by numerous other authors, it seems that their occurrence is rather erratic which makes it difficult to investigate or reliably exclude them.
2011-04-12
Technical Paper
2011-01-0419
Masayuki Shimizu, Kazunori Yageta, Yoshinori Matsui, Takahiro Yoshida
This paper describes a new 1.6-liter four-cylinder gasoline turbocharged engine with a direct injection gasoline (DIG) system and a twin continuously variable valve timing control (CVTC) system. Demands for higher environmental performance make it necessary to improve engine efficiency further. At the same time, improvement of power performance is important to enhance the appeal of vehicles and make them attractive to consumers. In order to meet these requirements, a 1.6-liter direct injection gasoline turbocharged engine has been developed. By using many friction reduction technologys, this engine achieves the high power performance of a 2.5-liter NA(Naturally Aspirated) gasoline engine and low fuel consumption comparable to that of a smaller displacement engine. In addition, this engine achieves low exhaust emission performance to comply with the US LEV2-ULEV and EU Euro5 emission requirements.
2011-04-12
Technical Paper
2011-01-0409
Christophe Guillon, Laurent Guerbe
In reciprocating internal combustion engines, the gas that leaks at the piston, rings and liner system is usually called blow-by. The blow-by is a complex mixture of air, burned and unburned gases and oil mist. In order to avoid external pollution, the blow-by is recycled in the air intake system. This is called Closed Crankcase Ventilation (CCV). The CCV is the cause of major issues as air intake system fouling, oil consumption and participation to the exhaust catalyst poisoning phenomena. During recent decades a quite simple oil separation system based on baffles was acceptable. Emissions regulations are now tougher and a more efficient blow-by separation system is required. A suitable and efficient means to achieve a good separation is to use the coalescence principle through a specific media. The coalescing separator is a good compromise between efficiency and pressure drop.
2010-04-12
Technical Paper
2010-01-1114
Ahmed A. Abdel-Rehim, Rady Sylym
Water piston internal combustion engine is a very simple propulsive engine invented in the 1970's to be used in different applications. The water piston engine consists simply of L shape tube immersed in water where the water column inside the tube acts as a piston. In the present study, two propulsive units from this engine were compared. The two units are identical in their dimensions except the exit port where one is curved and the other one is sharp. The effect of this shape on the engine thrust, fuel consumption, power and number of effective firing was investigated. The effect of combustion chamber size on engine performance is also considered for the two units in this study.
2010-04-12
Technical Paper
2010-01-1105
Liguang Li, Yanlong Luan, Zhe Wang, Jun Deng, Zhijun Wu
To develop a free-piston engine-alternator integrative power system for Hybrid Electric Vehicles, the key design parameters, such as reciprocating mass of the piston assembly, compression ratio, the ignition timing, the engine fuel consumption rate and power output, are studied based on the simulation. The results show that, the system simulation model of the free piston engine can predict the in-cylinder pressure vs. the piston's displacement being accurate enough as the test results from reported reference. The model can be employed to optimize the design parameters and to predict the fuel economy and power output. It provides the methods and bases for the free piston engine design and predicting the main performance parameters' values.
2010-04-12
Technical Paper
2010-01-0502
Alexandre Schalch Mendes, Rodrigo Tomoyose
This Paper presents a study of weight reduction in an exhaust manifold of a four cylinders, 3.0 liters Diesel engine. The mass of the entire engine shall be reduced from the current 290kg to 260kg and many components will be redesigned focused on this target. Basically, the wall thickness and flanges of the exhaust manifold will be redesigned and reduced to a value which shall guaranties the component durability. The calculations will be made determining the life cycle of the proposed exhaust manifold, checking if no structural problems can occur. The shape and size of the ducts remain unchanged for performance purposes and no material changes will be considered for the new component.
2010-04-12
Technical Paper
2010-01-0500
Abhijit Londhe, Aparajita Sen
The cylinder block for the power train has always been a classic example of concurrent engineering in which disciplines like NVH, Durability, thermal management and lubrication system layout contribute interactively for concept design. Since the concept design is based on engineering judgment and is an estimated design, the design iterations for optimization are inevitable. This paper aims at outlining a systematic approach for design of crankcase for fatigue which would eliminate design iterations for durability. This allows a larger scope for design improvement at the concept stage as the design specifications are not matured at this stage. A process of stress optimization is adopted which gives accurate dimensional input to design. The approach is illustrated with a case study where an existing crankcase was optimized for fatigue and significant weight reduction was achieved.
2010-04-12
Technical Paper
2010-01-0614
Norifumi Mizushima, Toshiro Yamamoto, Jin Kusaka, Susumu Sato
Compared with petroleum fuel, liquefied petroleum gas (LPG) demonstrates advantages in low CO₂ emission. This is because of propane (C₃H₈), n-butane (n-C₄H₁₀) and i-butane (i-C₄H₁₀), which are the main components of LPG, making H/C ratio higher. In addition, LPG is suitable for high efficient operation of a spark ignition (SI) engine due to its higher research octane number (RON). Because of these advantages, that is, diversity of energy source and reduction of CO₂, in the past several years, LPG vehicles have widely been used as the alternate gasoline vehicles all over the world. Consequently, it is absolutely essential for the performance increase in LPG vehicles to comprehend combustion characteristics of LPG. In this study, the differences of laminar burning velocity between C₃H₈, n-C4H10, i-C₄H₁₀ and regular gasoline were evaluated experimentally with the use of a constant volume combustion chamber (CVCC).
2010-04-12
Journal Article
2010-01-0655
Greg Wallace, Andrew P. Jackson, Stephen P. Midson
A turbocharger essentially consists of a turbine and an impeller wheel connected on a common shaft. The turbocharger converts waste energy from the exhaust into compressed air, which is pushed into an engine to produce more power and torque, as well as improving the overall efficiency of the combustion process. The compression ratio for modern diesel engines can be up to 5:1, which can be only achieved using a complex impeller design and very high rotation speeds (up to 150,000 rpm for small impellers). The complex geometry and very high running speeds of impellers creates high stresses at locations such as blade roots and around the bore, and so impellers normally fail from fatigue. Therefore, it is vital to minimize defects while fabricating turbocharger impellers. Current methods for producing aluminum turbocharger impellers are plaster casting or by forging + machining. However, both of these current methods have serious drawbacks.
2010-04-12
Journal Article
2010-01-0657
William (Jud) Dunlap, Alan Druschitz
Exhaust manifolds and turbocharger housings require good elevated temperature strength, good resistance to thermal fatigue and a stable microstructure. High silicon ductile iron, high silicon-molybdenum ductile iron and Ni-resist (a high nickel ductile iron) are the cast materials of choice. Unfortunately, molybdenum and nickel are expensive. In this study, a lower cost, high silicon-titanium, compacted graphite iron was developed and compared to high silicon ductile iron and higher cost, high silicon-molybdenum ductile iron. Room and elevated temperature strength data is presented.
2011-04-12
Journal Article
2011-01-0227
Sebastian Kunkel, Martin Werner, Georg Wachtmeister
This SAE Technical Paper gives a summary of the essential findings in the development and operation of a test engine dedicated to the measuring of the friction between the piston group and the liner. Firstly the fundamental demands on the high-precision and close to real engine operation friction measuring are laid out. Subsequently the basic engine, the measuring system based on the floating liner method including a gas balance device, as well as the implemented measuring technique are specified. Major influencing variables on the friction of the piston assembly and its interference variables are also summarized. Extensive information about the systematic and strategies for the test engine's operation startup are given in acknowledgement of influencing and interference variables. This strategy reduces the developmental and startup process of an engine dedicated to the measuring of piston group friction.
2011-04-12
Journal Article
2011-01-0140
Paolo Sementa, Bianca Maria Vaglieco, Francesco Catapano
The aim of this paper is the experimental investigation of the effect of direct fuel injection on the combustion process and pollutant formation in a spark ignition (SI) two-wheel engine. The engine is a 250cc single cylinder, four-stroke spark-ignition firstly equipped with a four-valve PFI head and then with GDI one operating with European commercial gasoline and Bio-ethanol. It is equipped with a wide sapphire window in the bottom of the chamber and quartz cylinder. In the combustion chamber, optical techniques based on 2D-digital imaging were used to follow the injection and flame propagation and spectroscopic measurements were carried out in order to evaluate the main radical species. Radical species such as OH and CH were detected and used to follow the chemical phenomena related to the fuel quality. Measurements were carried out at different engine speeds and combustion strategies based on different injection pressures.
2011-04-12
Journal Article
2011-01-0141
Javier Vera, Jaal Ghandhi
The post-flame oxidation of unburned hydrocarbons released from the ring-pack crevice was investigated for a small, air-cooled, spark-ignition utility engine. Spark timing sweeps were performed at 50, 75 and 100% load and speeds of 1800, 2400 and 3060 RPM while operating at a 12:1 air-fuel ratio, which is typical for these engines. A global HC consumption rate (GCR) was introduced based on the temporal profile of the mass released from the ring pack; the mass release after CA90 and up to the point where the remainder of the ring pack HC mass is equal to the exhaust HC level was taken as the mass oxidized, and a rate was defined based on this mass and the corresponding crank angle period over which this took place. For all conditions tested, the GCR varied with the spark timing; advanced spark timing gave higher GCR.
2011-04-12
Technical Paper
2011-01-0647
Brian Sangeorzan, Eva Barber, Brett Hinds
A new, 1-D analytical engine thermal management tool was developed to model piston, oil and coolant temperatures in the Ford 3.5L engine family. The model includes: a detailed lubrication system, including piston oil-squirters, which accurately represents oil flow rates, pressure drops and component heat transfer rates under non-isothermal conditions; a detailed coolant system, which accurately represents coolant flow rates, pressure drops and component heat transfer rates; a turbocharger model, which includes thermal interactions with coolant, oil, intake air and exhaust gases (modeled as air), and heat transfer to the surroundings; and lumped thermal models for engine components such as block, heads, pistons, turbochargers, oil cooler and cooling tower. The model was preliminarily calibrated for the 3.5L EcoBoost™ engine, across the speed range from 1500 to 5500 rpm, using wide-open-throttle data taken from an early heat rejection study.
2011-04-12
Technical Paper
2011-01-0613
Jun Sun, Xiaoyong zhao, Hu Wang
There is the direct interaction between the crankshaft and the crankshaft bearing in an internal combustion engine. Current lubrication analysis of the crankshaft bearing was generally limited in the tribology discipline, only the factors relating to the bearing were considered, and the journal axis was generally supposed to be parallel to the centerline of bearing. In reality, the crankshaft deformation under load will result in the journal misalignment in the bearing. Although the journal misalignment was considered in a few of the lubrication analyses of crankshaft bearings, the causes of journal misalignment were usually thought to be caused by the manufacture, the assembly errors and the deformation of cylinder block. In order to simplify the problem, the journal misalignment was generally assumed to have constant magnitude and direction in an operating cycle of engine.
2011-04-12
Journal Article
2011-01-0612
Georgios Livanos
The continuous increase of the green house emissions in conjunction with the limited and finite fuel resources make the improvement of efficiency of all engines, converting fuel chemical energy to mechanical energy, imperative. Even small increase in engine's mechanical efficiency, can be proved significant in economical and environmental terms. Towards this direction, the tribology studies of the Internal Combustion Engines, mainly used as propulsion, power generation and auxiliary drives, are considered important for the design of new engines and the improvement of existing ones. The objective of this paper is to present a simplified (analytical) model for the prediction of the instantaneous friction, developed on the main components of the piston-crank-slider mechanism of an internal combustion engine, including complete piston ring packs, piston skirts, connecting rod bearings and crankshaft main bearings.
2011-04-12
Technical Paper
2011-01-0611
Aron K. Neu, John J. Moskwa, Peter Robinson
A new method for instantaneous friction estimation in firing internal combustion engines has been developed in the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin - Madison. This Synthetic Variable approach, which has previously been used for combustion quality diagnostics, focuses on carefully measuring instantaneous engine speed and other easily measurable engine variables and combining them with dynamic models of other engine processes. This approach numerically strips away the dynamic effects that mask friction effects on engine speed and reveals friction estimates with clarity. This information could be useful for engine designers and developers to assist in accurately understanding the sources of instantaneous friction within the running engine. The friction results from these studies have been very encouraging.
2011-04-12
Technical Paper
2011-01-0700
Andreas Sidorow, Rolf Isermann, Francesco Cianflone, Gerhard Landsmann
Faults in the intake and exhaust path of turbocharged common-rail diesel engines lead to an increase of emissions and to performance losses. Fault detection strategies based on plausibility checks, threshold based trend or limit checking of sensor data are not able to detect and isolate all faults appearing in the intake and exhaust path without increasing of the number of sensors. The need to minimize mass and reduce cost, including the number of sensors, while maintaining robust performance leads to higher application of models for intake and exhaust path components. Therefore a concept of model based fault detection with parity equations is considered. It contains the following parts: modeling, residual generation with parity equations using parallel nonlinear models, fault to symptom transformation with masking of residuals dependent on the operating point and limit violation checking of the residuals.
2011-04-12
Technical Paper
2011-01-0610
Jan Macek, David Fuente, Miloslav Emrich
The current state-of-the-art offers two extremes of engine mechanical loss models: pure empirical models, using, e.g., regression models based on experimental results, and full-sized 3-D hydrodynamic friction models, solving Reynolds-like lubrication equations for complicated geometry of piston ring/cylinder liner or load-distorted shapes of crankshaft/connecting rod bearings and journals. Obviously, the former method cannot be reliably extrapolated while the latter is too complicated, especially for the early stage of design. The aim of the current paper is describing the development and experimental calibration of the physical cranktrain model for FMEP prediction, based on simplified phenomenological model of mixed friction. The model uses simply defined shapes of Stribeck curves (friction coefficient) in dependence on Sommerfeld number, i.e., on effective sliding velocity, oil viscosity, dimension scaling factor and the normal force load.
2010-04-12
Technical Paper
2010-01-1224
Liangjun Hu, Ce Yang, Harold Sun, Eric Krivizky, Louis Larosiliere, Jizhong Zhang, Ming-Chia Lai
Self recirculation casing treatment has been showed to be an effective technique to extend the flow range of the compressor. However, the mechanism of its surge extension on turbocharger compressor is less understood. Investigation and comparison of internal flow filed will help to understand its impact on the compressor performance. In present study, experimentally validated CFD analysis was employed to study the mechanism of surge extension on the turbocharger compressor. Firstly a turbocharger compressor with replaceable inserts near the shroud of the impeller inlet was designed so that the overall performance of the compressor with and without self recirculation casing treatment could be tested and compared. Two different self recirculation casing treatments had been tested: one is conventional self recirculation casing treatment and the other one has deswirl vanes inside the casing treatment passage.
2010-04-12
Technical Paper
2010-01-1220
Marcello Canova, Fabio Chiara, Giorgio Rizzoni, Yue-Yun Wang
Two-stage turbochargers are a recent solution to improve engine performance, reducing the turbo-lag phenomenon and improving the matching. However, the definition of the control system is particularly complex, as the presence of two turbochargers that can be in part operated independently requires effort in terms of analysis and optimization. This work documents a characterization study of two-stage turbocharger systems. The study relies on a mean-value model of a Diesel engine equipped with a two-stage turbocharger, validated on experimental data. The turbocharger is characterized by a VGT actuator and a bypass valve (BPV), both located on the high-pressure turbine. This model structure is representative of a “virtual engine”, which can be effectively utilized for applications related to analysis and control. Using this tool, a complete characterization was conducted considering key operating conditions representative of FTP driving cycle operations.
2010-04-12
Technical Paper
2010-01-1221
Fredrik Westin, Ragnar Burenius
The paper describes a measurement procedure to measure complete 2-stage turbo systems (TST - Two Stage Turbo) in a turbocharger test rig. The possibility to measure the complete range of operation of the series-sequential mode of the 2-stage system is proven. Also the performance is broken down for the two turbochargers individually; both when operating as a part of the TST system and measured as completely separated individuals. The maps measured individually were then used to calculate a composed TST-map as if there would be no losses between the two stages, and this composed map was compared to the measured TST-map. The difference between these two maps is interpreted as interstage losses when packaging the two turbochargers as closely as is necessary to fit in the car. The breakdown showed that the entire difference is not solely due to losses of total pressure interstage.
2010-04-12
Technical Paper
2010-01-1219
David Japikse, Colin Osborne, Peter Klein, William Pope, Eric Krivitzky
While turbocharging has existed for a full century, its significance has increased very rapidly in the past few decades. At the heart of good turbocharger performance is an excellent compressor stage, or stages, that must be efficient, stable, lightweight, and inexpensive to manufacture. Based on decades of design experience, the performance modeling of these stages is presented, techniques for design optimization are reviewed, and means for rapid machining are explained. The reader will gain insight to some of the most critical aspects of compressor design.
2010-04-12
Technical Paper
2010-01-1194
Angelo Onorati, Gianluca Montenegro, Gianluca D'Errico, Federico Piscaglia
This paper describes a detailed analysis of the unsteady flows in the intake and exhaust systems of a modern four-cylinder, turbocharged Diesel engine by means of advanced numerical tools and experimental measurements. In particular, a 1D-3D integrated fluid dynamic model, based on the GASDYN (1D) and Lib-ICE (3D) codes, has been developed and applied for the schematization of the geometrical domain and the prediction of the wave motion in the whole intake and the exhaust systems, including the air cleaner, the intercooler, the after-treatment devices and the silencers. Firstly, a detailed 1D simulation has been carried out to predict the pressure pulses, average pressures and temperatures in several cross-sections of the pipe systems for different speeds and loads, considering the complex geometry of the air filter, the intake manifold, the intercooler and the exhaust manifold.
2010-04-12
Journal Article
2010-01-1192
Thomas H. Fischer, Mark Sellnau, Jeffrey Pfeiffer, Daniel Gauthier
Intake camshaft retard beyond that necessary for reliable cold start-ability is shown to improve part-load fuel economy. By retarding the intake camshaft timing, engine pumping losses can be reduced and fuel economy significantly improved. At high engine speeds, additional intake cam retard may also improve full-load torque and power. To achieve these benefits, an intake camshaft phaser with intermediate lock pin position (ILP) and increased phaser authority was developed. ILP is necessary to reliably start at the intermediate phase position for cold temperatures, while providing increased phaser retard under warm conditions. The phaser also provides sufficient intake advance to maximize low-speed torque and provides good scavenging for boosted engine applications. Design and development of the intermediate locking phaser system is described. The pros and cons of various methods of accomplishing locking and unlocking a phaser are illustrated.
Viewing 1 to 30 of 6230

Filter

  • Range:
    to:
  • Year: