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Training / Education
2014-12-03
Turbocharging is already a key part of heavy duty diesel engine technology. However, the need to meet emissions regulations is rapidly driving the use of turbo diesel and turbo gasoline engines for passenger vehicles. Turbocharged diesel engines improve the fuel economy of baseline gasoline engine powered passenger vehicles by 30-50%. Turbocharging is critical for diesel engine performance and for emissions control through a well designed exhaust gas recirculation (EGR) system. In gasoline engines, turbocharging enables downsizing which improves fuel economy by 5-20%. This web seminar will explore turbocharging for gasoline and diesel (heavy and light duty) engines, including the fundamentals of turbocharging, design features, performance measures, and matching and selection criteria.
Training / Education
2014-11-10
The need to control emissions and maintain fuel economy is driving the use of advanced turbocharging technology in both diesel and gasoline engines. As the use of diesel engines in passenger car gasoline and diesel engines increases, a greater focus on advanced turbocharging technology is emerging in an effort to reap the benefits obtained from turbocharging and engine downsizing. This seminar covers the basic concepts of turbocharging of gasoline and diesel engines (light and heavy duty), including turbocharger matching and charge air and EGR cooling, as well as associated controls. The limitations and future possibilities of today's systems will be covered, as well as details on how emerging technologies will impact engine/vehicle performance.
Event
2014-10-22
This session describes design, performance, and operating characteristic of crucial peripheral devices, intake and exhaust manifolds, and engine block structures and features.
Event
2014-10-21
This session will cover conceptual, modeling and experimental studies relating to advanced turbochargers/superchargers and advanced boosting systems to achieve increased power density, better fuel economy, and reduced emissions.
Technical Paper
2014-10-13
Ian S. Park, Andrew M. Williams
Abstract Modelling of turbochargers based on steady state operating maps for turbine and compressor rotors is widely recognized to have limitations arising from flow pulsations and heat transfer effects that are not well accounted for by interpolation and extrapolation from the mapped data. With implementation of low pressure exhaust gas recirculation systems and multi-stage boosting, the inlet conditions of centrifugal compressors vary more widely than traditional single stage compression systems. Understanding the impact of the inlet conditions on irreversibilities, and therefore efficiency complements existing works on pulse flow and heat transfer effects in informing the engine modelling community. This research experimentally explores the effect of inlet pressure and temperature on the total-total efficiency of a steady flow centrifugal compressor across a range of conditions in isolation of pulse flow effects and with negligible heat transfer. The results suggest that for any given corrected mass flow rate and total-total pressure ratio the isentropic efficiency is dependent on inlet conditions.
Technical Paper
2014-10-13
Yasuhiro Hikita, Masahiro Kawahara, Naoto Noguchi
Abstract On internal combustion engines, the intake and exhaust valves are reciprocated by the cam mechanism. ‘Cam-shower’ is oil supplying device for each cam of a camshaft. The conventional cam-shower is simple pipe shape with several same size outlets for each cam. Oil from cylinder head is supplied in the middle point of cam-shower pipe. The oil flow of outlets near the oil supplied point is large amount, and outlet far from supplied point is small. The distribution of oil flow from each outlet is uneven. A new structure of cam-shower has been developed, and it has two important features. First, it has branched oil passage like cereoid cactus. Second, supplied oil flow from cylinder head to a cam-shower is intermittent by using throughhole passage in a camshaft journal. The new developed cam-shower properly distributes oil flow to each cam evenly and reduces wasted oil flow, so that total amount of oil flow of the cam-shower can be remarkably reduced by 90%. Then small discharge rate of the oil pump for engine can be set up and its driving torque gets lower.
Technical Paper
2014-10-13
Jose Serrano, Pablo Olmeda, Francisco Arnau, Artem Dombrovsky
These days many research effort on internal combustion engines is centred on optimising turbocharger matching and performance on the engine. In the last years a number of studies have pointed that heat transfer phenomena have a strong effect on turbocharger behaviour. The difficulty of determining the necessary data to take into account such phenomena arises as a consequence of the little information provided by turbocharger manufacturers. In this background, Original Engine Manufacturers (OEM) need general engineering tools able to provide reasonably precise results in predicting the mentioned heat transfer phenomena. Therefore, the purpose of this paper is to provide a procedure, applicable to small automotive turbochargers, able to give necessary heat transfer properties that can be used in a lumped 1D turbocharger heat transfer model. Such model must be suitable to work coupled to whole-engine simulation codes (such as GT-Power or Ricardo WAVE) for its usage in a global engine models by the OEM.
Technical Paper
2014-10-13
Elias Sundström, Bernhard Semlitsch, Mihai Mihaescu
Abstract Numerical analysis methods are used to investigate the flow in a ported-shroud centrifugal compressor under different operating conditions, i.e. several mass flow rates at two different speed lines. A production turbocharger compressor is considered, which is widely used in the heavy automotive sector. Flow solutions obtained under steady-state and transient flow assumptions are compared with available experimental data. The steady-state Reynolds Averaged Navier-Stokes method is used to assess the overall time averaged flow and the global performance parameters. Additionally, the Large Eddy Simulation (LES) approach is employed to capture the transient flow features and the developed flow instabilities at low mass flow rates near the surge line. The aim of this study is to provide new insights on the flow instability phenomena in the compressor flow near surge. Comparison of flow solutions obtained for near-optimal efficiency and near-surge conditions are carried out. The unsteady features of the flow field are quantified by means of Fourier transformation analysis, Proper Orthogonal Decomposition and Dynamic Mode Decomposition.
Technical Paper
2014-10-13
Oliver P. Taylor, Richard Pearson, Richard Stone, Phil Carden, Helen Ballard
Abstract Most major regional automotive markets have stringent legislative targets for vehicle greenhouse gas emissions or fuel economy enforced by fiscal penalties. Large improvements in vehicle efficiency on mandated test cycles have already taken place in some markets through the widespread adoption of technologies such as downsizing or dieselization. There is now increased focus on approaches which give smaller but significant incremental efficiency benefits such as reducing parasitic losses due to engine friction. Fuel economy improvements which achieve this through the development of advanced engine lubricants are very attractive to vehicle manufacturers due to their favorable cost-benefit ratio. For an engine with components which operate predominantly in the hydrodynamic lubrication regime, the most significant lubricant parameter which can be changed to improve the tribological performance of the system is the lubricant viscosity. Low viscosity lubricants are increasingly being specified by vehicle manufacturers who are now more frequently working directly with the lubricant supplier to design fluids specific to their requirements.
Technical Paper
2014-10-13
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.
Technical Paper
2014-10-13
Zhi-yong Chen, Ning Sun, Wenku Shi
Abstract In order to improve structure and performance of magneto-rheological dual mass flywheel (MRF-DMF), some parameters effects on dynamic characteristics are acquired by parameters analysis. The dynamic stiffness and loss angle in different current and different frequency are gained through dynamic characteristic test. The fluid-structure interaction finite element model of MRF-DMF is built and the accuracy is verified by comparison between test and simulation. Based on the model, the parameters analysis is done and the law of MRF viscosity, arc spring stiffness, working clearance, rotor radius and axial width effect on dynamic characteristics are gained, it will prove some guidance for the structure and performance improvement.
Technical Paper
2014-10-13
He Changming, Xu Sichuan
The in-cylinder tumble intensity of GDI engine is crucial to combustion stability and thermal efficiency, required to be different for the different operation conditions. A new variable tumble system (VTS) applied to GDI engine was introduced to meet tumble ratio requirements in various situations. The transient gas exchange of four combustion systems all were investigated during both intake and compression strokes based on CFD simulation, namely (1) Case 1-Intake port B (with flap valve)/Spherical piston crown; (2) Case 2-Intake port B (without flap valve)/Spherical piston crown; (3) Case 3- Intake port A/Spherical piston crown; (4) Case 4-Intake port A/Dented piston crown. The simulated results of dynamic tumble ratio showed that during the whole intake process the dynamic tumble ratio of Case1 was obviously higher than other Cases with the same boundary conditions, and the maximum value was about 5∼6 times higher. The crank angle range, in which the strong tumble motion fully developed, was merely about 70°CA, roughly from 410°CA to 480°CA.
Technical Paper
2014-10-13
Mohd Farid Muhamad Said, Azhar Bin Abdul Aziz, Zulkanain Abdul Latiff, Amin Mahmoudzadeh Andwari, Shahril Nizam Mohamed Soid
Abstract Many efforts have been invested to improve the fuel efficiency of vehicles mainly for the local consumers. One of the main techniques to have better fuel efficiency is cylinder deactivation system. In this paper, the main research area is focus on the investigation of cylinder deactivation (CDA) technology on common engine part load conditions within common Malaysian driving condition. CDA mostly being applied on multi cylinders engines. It has the advantage in improving fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6 liter four cylinders gasoline engine is studied. One-dimensional (1-D) engine modeling is performed to investigate the effect of intake and exhaust valve strategy on engine performance with CDA. The 1-D engine model is constructed starts from the air-box cleaner up to exhaust system according to the 1.6 liter actual engine geometries. The model is simulated at various engine speeds with full load condition.
Technical Paper
2014-10-13
D. Saravanan, Anish Gokhale, N. Karthikeyan
The Torque from an engine is a very critical parameter which controls the drivability of the vehicle, better torque availability at Partially Open Throttle (POT) condition improves drivability at city driving condition and better torque at Wide Open Throttle (WOT) condition improves cruising at highway driving condition, conventionally engine produces better torque at one particular operating condition leaving poor drivability at others. The Torque characteristics of an engine depends upon the volumetric efficiency of the engine. The volumetric efficiency of a naturally aspirated engine can be improved by tuning the intake manifold. With an overall improvement in volumetric efficiency throughout the engine operating conditions better torque curve can be achieved, which facilitates improved drivability. For improving volumetric efficiency, several technologies were developed and used, among that Dual Intake Manifold system is one where the flow of charge is channelized between longer and shorter flow path depending on the engine operating condition.
Technical Paper
2014-10-13
Xinyan Wang, Hua Zhao, Hui Xie, Bang-Quan He
Abstract SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In order to stabilize the hybrid combustion process, the port fuel injection (PFI) combined with gasoline direct injection (GDI) strategy is proposed in this study to form the in-cylinder fuel stratification to enhance the early flame propagation process and control the auto-ignition combustion process. The effect of bowl piston shapes and fuel injection strategies on the fuel stratification characteristics is investigated in detail using three-dimensional computational fluid dynamics (3-D CFD) simulations. Three bowl piston shapes with different bowl diameters and depths were designed and analyzed as well as the original flat piston in a single cylinder PFI/GDI gasoline engine. An engine operating load of IMEP=3.6 bar was selected to evaluate the effect of piston shapes on the in-cylinder conditions, including flow conditions, fuel stratification patterns, thermal conditions and fuel evaporation ratios.
Technical Paper
2014-10-13
Jianyi Tian, Hongming Xu, Ramadhas Arumugam Sakunthalai, Dai Liu, Cheng Tan, Akbar Ghafourian
Abstract Engine transient operation has attracted a lot of attention from researchers due to its high frequency of occurrence during daily vehicle operation. More emissions are expected compared to steady state operating conditions as a result of the turbo-lag problem. Ambient temperature has significant influences on engine transients especially at engine start. The effects of ambient temperature on engine-out emissions under the New European Driving Cycle (NEDC) are investigated in this study. The transient engine scenarios were carried out on a modern 3.0 L, V6 turbocharged common rail diesel engine fuelled with winter diesel in a cold cell within the different ambient temperature ranging between +20 °C and −7 °C. The engine with fuel, coolant, combustion air and lubricating oil were soaked and maintained at the desired test temperatures during the transient scenarios. Instantaneous engine performances including torque and speed, gaseous emissions such as CO, THC and NOx, and particulate emissions for its number and mass are analyzed during each transient scenario under different ambient conditions.
Technical Paper
2014-10-13
Eiichi Takahashi, Hirokazu Kojima, Hirohide Furutani
Abstract Dielectric barrier discharge (DBD) was applied to control the pressure-rise rate of homogeneous compression ignition, which is an important obstacle for homogeneous charge combustion engines. DBD can produce nonthermal plasmas and has been generated in air/fuel mixtures to reform some of the fuel molecules found in such mixtures. This generally shortens the ignition delay of compression ignition of the air/fuel premixture. Stratification of the reformed premixture in the combustion chamber was achieved by pulsed DBD irradiation during the induction process. The formation of inhomogeneous distribution of the reformed premixture is expected by the formation of discharge at the end of the intake processes. A demonstrative experiment was conducted by using a rapid compression and expansion machine. A simple plasma reactor was developed and installed at the intake tube. High-voltage, high-frequency pulses were applied to form plasmas. n-Heptane was used as fuel. Characteristic oscillation was observed at the maximum of pressure history in the compression ignition experiment without using plasma.
Technical Paper
2014-10-13
Bo Hu, Colin Copeland, Chris Brace, Sam Akehurst, Alessandro Romagnoli, Ricardo Martinez-Botas, J.W.G Turner
Abstract Engines equipped with pressure charging systems are more prone to knock partly due the increased intake temperature. Meanwhile, turbocharged engines when operating at high engine speeds and loads cannot fully utilize the exhaust energy as the wastegate is opened to prevent overboost. The turboexpansion concept thus is conceived to reduce the intake temperature by utilizing some otherwise unexploited exhaust energy. This concept can be applied to any turbocharged engines equipped with both a compressor and a turbine-like expander on the intake loop. The turbocharging system is designed to achieve maximum utilization of the exhaust energy, from which the intake charge is over-boosted. After the intercooler, the turbine-like expander expands the over-compressed intake charge to the required plenum pressure and reduces its temperature whilst recovering some energy through the connection to the crankshaft. It is anticipated that such a concept has benefits for knock resistance and energy recovery despite suffering higher pumping losses.
Technical Paper
2014-10-13
Ben Leach, Richard Pearson, Rana Ali, John Williams
Abstract Engine downsizing is a key approach employed by many vehicle manufacturers to help meet fleet average CO2 emissions targets. With gasoline engines in particular reducing engine swept volume while increasing specific output via technologies such as turbocharging, direct injection (DI) and variable valve timing can significantly reduce frictional and pumping losses in engine operating areas commonly encountered in legislative drive cycles. These engines have increased susceptibility to abnormal combustion phenomena such as knock due to the high brake mean effective pressures which they generate. This ultimately limits fuel efficiency benefits by demanding use of a lower geometric compression ratio and sub-optimal late combustion phasing at the higher specific loads experienced by these engines. The lower expansion ratio and retarded combustion in turn increase the exhaust gas temperature, which often leads to a need to add extra fuel that cannot be fully combusted in order to cool and protect engine components from thermal damage.
Technical Paper
2014-10-13
Kazushi Tamura, Moritsugu Kasai, Yukinobu Nakamura, Tomoyuki Enomoto
Abstract To explore the measures that can be used to improve the fuel economy of internal combustion engines, we investigated how friction at the piston ring-cylinder liner interface is influenced by the boundary lubrication performance of engine oils. We formulated several engine oils with varying boundary lubrication performance and tested them for ring-liner friction by using a floating liner friction tester. We used friction modifiers (FMs) to modify the boundary lubrication performance of engine oils. We found that ring-liner friction is well correlated with the friction coefficients in boundary lubrication regimes when measured by a laboratory friction tester. We also found that the impact of the boundary lubrication performance of engine oils was emphasized in low viscosity engine oils. It makes it possible for improved boundary lubrication performance to inhibit or overcome the viscosity reduction-induced increase of friction energy. These results suggest that FM formulation is as important as viscosity modification for next-generation engine oils to achieve better fuel economy.
Technical Paper
2014-10-13
Wenjie Qin, Lunjing Duan
In order to predict cam wear in valve trains of engines quantitatively, multi-body system dynamic analysis, finite element quasi-statics contact analysis and numerical calculation of elastohydrodynamic lubrication are applied to obtain the dynamic loads, the time histories of contact pressure and the oil film thicknesses in a cam-tappet pair. Using this methodology, the wear depth of the cam in the valve train of a heavy load diesel engine is calculated, which is in good agreement with the measured value in the practical tests. The results show that the cam-tappet is operated in a mixed lubricant or a boundary lubricant regime and the wear depths on both the sides of the cam have been found to be the greatest.
Technical Paper
2014-10-13
Mohamadamin Shamsderakhshan, Shahaboddin Kharazmi
The aim of this paper is to choose the convenient turbocharger for the OM355 naturally aspirated diesel engine and turn it to a turbocharged one. For this, 1D1 computer simulation code is used and simulation results are validated with experimental measurements. Finally, by selecting a proper turbocharger, engine power increases about 50% and specific fuel consumption decreases about 4%. Moreover, effects of exhaust manifold geometry and ambient condition on performance parameters of the turbocharged diesel engine are investigated.
Technical Paper
2014-10-13
Qiyou Deng, Richard Burke
Abstract Current turbocharger models are based on characteristic maps derived from experimental measurements taken under steady conditions on dedicated gas stand facility. Under these conditions heat transfer is ignored and consequently the predictive performances of the models are compromised, particularly under the part load and dynamic operating conditions that are representative of real powertrain operations. This paper proposes to apply a dynamic mathematical model that uses a polynomial structure, the Volterra Series, for the modelling of the turbocharger system. The model is calculated directly from measured performance data using an extended least squares regression. In this way, both compressor and turbine are modelled together based on data from dynamic experiments rather than steady flow data from a gas stand. The modelling approach has been applied to dynamic data taken from a physics based model, acting as a virtual test cell. Varying frequency sinusoidal signals were applied to the compressor and turbine pressure ratios and turbine inlet temperature to drive the physic model.
Event
2014-10-09
Session CV302 focuses on the mechanical design of Powertrain and drive train components, sub-systems, and systems. Relevant topics include but are not limited to: Materials, coatings, and processes Design/Analysis/Test methods Novel designs of Powertrain and drive train components and sub-systems: Noise/Vibrations of Powertrain/drive train components and sub-systems- gear rattle, torsional vibration, sound power, etc. Powertrain and drive train includes but is not limited to engine, mounting, transmission, driveshaft(s),differential(s),dropbox(es), and axles.
Training / Education
2014-10-06
As diesel engines become more popular, a fundamental knowledge of diesel technology is critical for anyone involved in the diesel engine support industry. This course will explain the fundamental technology of diesel engines starting with a short but thorough introduction of the diesel combustion cycle, and continue with aspects of engine design, emission control design, and more. An overview of developing technologies for the future with a comprehensive section on exhaust aftertreatment is also included. The text, Diesel Emissions and Their Control, authored by Magdi Khair and W. Addy Majewski is included with the seminar.
Training / Education
2014-10-02
The purpose of this course is to provide an overview of the factors in the cylinder kit assembly of natural gas, gasoline, and diesel engines that affect oil consumption, ring and cylinder bore wear, and blow-by. This course includes background and the evolution of designs and materials currently employed in modern engines as well as providing an overview of computer models, designs, and material systems that can be utilized to optimize the performance of new engines. An overview of the trends in materials and designs employed in U.S., European and Japanese engines will be presented.
Technical Paper
2014-09-30
Pulkit Agarwal, Andrea Vacca, Kelong Wang, Kwang Sun Kim, TaeGul Kim
Abstract Radial piston units find several applications in fluid power, offering benefits of low noise and high power density. The capability to generate high pressures makes radial piston pumps suitable for clamping function in machine tools and also to operate presses for sheet metal forming. This study is aimed at developing a comprehensive multidomain simulation tool to model the operation of a rotating cam type radial piston pump, with particular reference to the lubricating gap flow between the pistons and the cylinder block. The model consists of a first module which simulates the main flow through the unit according to a lumped parameter approach. This module evaluates the features of the displacing action accounting for the detailed evaluation of the machine kinematics and for the mechanical dynamics of the check valves used to control the timing for the connection of each piston chamber with the inlet and outlet port. The estimation of the instantaneous pressure within each displacement chamber is utilized in a second module dedicated to the prediction of the lubricating gap flow between the pistons and the cylinder.
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