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Viewing 1 to 30 of 43636
2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-03-28
Technical Paper
2017-01-0638
Neerav Abani, Nishit Nagar, Rodrigo Zermeno, Michael chiang, Isaac Thomas
Heavy-duty vehicles, currently the second largest source of fuel consumption and carbon emissions are projected to be fastest growing mode in transportation sector in future. There is a clear need to increase fuel efficiency and lower emissions for these engines. The Achates Power Opposed-Piston Engine has the potential to address this growing need. In this paper, results will be presented for a 9.8L three-cylinder OP Engine that shows the potential of achieving 51%+ brake thermal efficiency (BTE), while simultaneously satisfying 4.0 g/kWhr engine out NOx and 0.01 g/kWhr engine-out soot. The OP Engine architecture can meet this performance without the use of additional technologies such as thermal barrier coatings, waste heat recovery or additional turbo-compounding.
2017-03-28
Technical Paper
2017-01-0789
Tobias Johansson, Ola Stenlaas
Typically the combustion in an internal combustion engine is open-loop controlled. The introduction of a cylinder pressure sensor opens the possibility to introduce a virtual combustion sensor. This virtual sensor is a possible enabler for closed-loop combustion control and thus the possibility to counteract effects as engine part to part variation, component ageing and fuel quality diversity. The extent to which these effects can be counteracted is determined by the detection limits of the virtual combustion sensor. To determine the limitation of the virtual combustion sensor a virtual combustion sensor system was implemented based on a one-zone heat-release analysis, including signal processing of the pressure sensor input. Typical error sources in a heavy-duty engine were identified and quantified. The virtual combustion sensor system was presented with flawed signals and the sensors sensitivities to the errors were quantified.
2017-03-28
Technical Paper
2017-01-0710
Yilong Zhang, Renlin Zhang, Lingzhe Rao, Sanghoon Kook
Soot particles emitted from modern diesel engines, despite significantly lower total mass, show higher reactivity and toxicity than black-smoking old engines, which cause serious health and environmental issues. Soot nanostructure, i.e. the internal structure of soot particles composed of nanoscale carbon fringes, can provide useful information to the investigation of the particle reactivity and its oxidation status. This study presents the nanostructure details of soot particles sampled directly from diesel flames in a working diesel engine as well as from exhaust gases to compare the internal structure of soot particles in the high formation stage and after in-cylinder oxidation. Thermophoretic soot sampling was conducted using an in-house-designed probe with a lacy transmission electron microscope (TEM) grid stored at the tip.
2017-03-28
Technical Paper
2017-01-0657
Lewis Gene Clark, Sanghoon Kook, Qing Nian Chan, Evatt R. Hawkes
This study investigates the effect of injection timing on the high-load combustion performance of a split-injection strategy in a spark-ignition direct-injection (SIDI) engine. Performance parameters derived from in-cylinder pressure data are analysed alongside high-speed natural flame luminosity images in order to obtain relationships between engine output and flame propagation behaviour. Trends in parameters such as indicated mean effective pressure (IMEP) and total heat release are found to be multimodal; as early injections aid the mixture formation process whereas late injections may lead to an increase in turbulence intensity at the point of ignition. Analysis of the high-speed images provides a further explanation of the observed results through investigating flame propagation speed and global eccentricity (i.e. non-circularity).
2017-03-28
Technical Paper
2017-01-0210
Ahmed Imtiaz Uddin, Abd El-Rahman Ali Hekal, Dipan P. Arora, Alaa El-Sharkawy, Sadek S. Rahman
With the increase in demand of fuel efficient transportation system, various efforts have been made to collect waste energies to reduce the fuel consumption and emissions in the automobiles. Currently, in a typical internal combustion engine, approximately one third of the fossil fuel combustion by-product is wasted heat. By collecting the heat emitted through the exhaust systems using heat exchanger concept can be used to increase the passenger heating and comfort during cold ambient conditions as well as reduction of exhaust system surface temperatures. Lower exhaust surface temperature improves the durability of various under-hood and underbody components near the exhaust pipe. In this paper, the effects of integrating a gas/coolant heat exchanger close to the engine catalytic converter on reduction of the exhaust surface temperature for various real-world dynamic driving conditions are presented.
2017-03-28
Technical Paper
2017-01-0215
Mohammad Nahid, Amin Sharfuzzaman, Joydip Saha, Harry Chen, Sadek S. Rahman
More stringent Federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems to best utilize the waste heat and improve driveline efficiency. The final drive unit in light and heavy duty trucks usually consists of geared transmission and differential housed in a lubricated axle. The automotive rear axles is one of the major sources of power loss in the driveline due to gear friction, churning and bearing loss and have a significant effect on overall vehicle fuel economy. These losses vary significantly with the viscosity of the lubricant. Also the temperatures of the lubricant are critical to the overall axle performance in terms of power losses, fatigue life and wear.
2017-03-28
Technical Paper
2017-01-0213
Rezwanur Rahman, Sadek S. Rahman
The demand for Hybrid Electrified Vehicles (HEVs) is increasing due to government regulations on fuel economy. The battery systems in a PHEV have achieved tremendous efficiency over past few years. The system has become more delicate and complex in architecture which requires sophisticated thermal management. Primary reason behind this is to ensure effective cooling of the cells. Hence the current work has emphasized on developing a “Physics based” thermal management modeling framework for a typical battery system. In this work the thermal energy conservation has been analyzed thoroughly in order to develop necessary governing equations for the system. Since cooling is merely a complex process in HEV battery systems, the underlying mechanics has been investigated using the current model. The framework was kept generic so that it can be applied with various architectures. In this paper the process has been standardized in this context.
2017-03-28
Technical Paper
2017-01-0629
John Kuo, George Garfinkel
Detailed thermal modeling of liquid-cooled vehicle traction battery assemblies using Computational Fluid Dynamics (CFD) analysis techniques usually involves large models to accurately resolve small cooling channel details. For large battery packs, some of these meshes may exceed current computational capabilities or result in long and expensive computational efforts. Moreover, only steady-state thermal predictions are usually performed, as drive-cycle transient simulations become impractical due to the exceedingly long solving times. To tackle this problem, an innovative segregated method has been developed for thermal analysis of liquid-cooled traction batteries, where battery cells and their active cooling system are divided into three parts: the cell, the cold plate and the interface between them.
2017-03-28
Technical Paper
2017-01-0829
Gina M. Magnotti, Caroline L. Genzale
The atomization and initial spray formation processes in direct injection engines are not well understood due to the experimental and computational challenges associated with resolving these processes. Although different physical mechanisms, such as aerodynamic-induced instabilities and nozzle-generated turbulence and cavitation, have been proposed in the literature to describe these processes, direct validation of the theoretical basis of these models under engine-relevant conditions has not been possible to date. Recent developments in droplet sizing measurement techniques offer a new opportunity to evaluate droplet size distributions formed in the central and peripheral regions of the spray. There is therefore a need to understand how these measurements might be utilized to validate unobservable physics in the near nozzle-region.
2017-03-28
Technical Paper
2017-01-0750
Shuli Wang, Kyle van der Waart, Bart Somers, Philip de Goey
The optimal fuel for partially premixed combustion (PPC) is considered to be a gasoline boiling range fuel with an octane number around 70. Higher octane number fuels are considered problematic in respect with low load and idle conditions. In previous studies the intake air temperature do not exceed 30oC. Possibly by increasing intake air temperatures the load range could be extended. In this study primary reference fuels (PRF) (iso-octane and n-heptane blend) with octane numbers of 70, 80, and 90 are tested on an adapted commercial diesel engine under partially premixed combustion mode to investigate the potential of these higher octane number fuels in low load and idle conditions. During testing combustion phasing and intake air temperature are varied to investigate the combustion stability, combustion characteristics, emissions and efficiency under low load and idle conditions.
2017-03-28
Technical Paper
2017-01-0849
Chao Gong, Roland Baar
The present work has its technical background in the field of Diesel injection systems of combustion engines and compares the effects of two kinds of remedies (re-meshing technique and linear interpolation technique) on mesh deformation. Mathematical formulation of moving grids has been proposed to guide the change of cell volume before. In this study, CFD (Computational Fluid Dynamics) analysis was mainly involved to study the internal nozzle behaviours and spray characteristics. An external library concept was introduced to couple the internal nozzle injection process with spray formation. In addition, all dynamic simulations were performed under a double-axis system. The comparison between simulation and experimental results shows that the integration of the traditional mesh deformation technique with the re-meshing or linear interpolation technique can repair mesh deformation and further contribute to better simulation results.
2017-03-28
Technical Paper
2017-01-0732
Stijn Broekaert, Thomas De Cuyper, Michel De Paepe, Sebastian Verhelst
In recent years, Homogeneous Charge Compression Ignition (HCCI) engines have received much interest, because they combine a high thermal efficiency with near-zero emissions of NOx and soot. However, the maximum attainable load is limited by the occurrence of ringing combustion. This happens when the combustion rate is too fast, leading to pressure oscillations in the combustion chamber accompanied by a knocking sound. Some researchers have hypothesized that these pressure oscillations increase the heat transfer from the combustion gases to the cylinder wall, due to the breakup of the thermal boundary layer. No experimental results are available to support this hypothesis, as no experimental studies have been conducted to investigate the heat transfer during ringing operation.
2017-03-28
Technical Paper
2017-01-0874
Thorsten Langhorst, Felix Rosenthal, Thomas Koch
Throughout the world cost-efficient Naphtha streams are available in refineries. Owing to less processing, CO2 emissions emitted in course of production of these fuels are significantly lower than with conventional fuels. In common CI/SI engines, however, the deployment of Naphtha is considerably restricted due to unfavourable fuel properties, e.g. low cetane/octane numbers. Former investigations illustrated high knocking tendency for SI applications and severe pressure rise for CI combustion. Moreover, the focus of past publications was on passenger vehicle applications. Hence, this paper centers on heavy-duty stationary engine applications. Consequently, measures to increase the technically feasible IMEP with regard to limitations in knocking behaviour and pressure rise were explored whilst maintaining efficient combustion and low emissions.
2017-03-28
Technical Paper
2017-01-0692
Haiying Li, Kun Wang, Lei Wang, Yufeng Li, Junting Fan
To increase the intake mass flow rate on a Downsizing diesel engine, the tilting axis of intake valve was chosen to enlarge the intake valve diameter Thus cylinder head had to be redesigned to meet this demand. Geometry of cylinder head made effect in organization of in-cylinder flow, fuel-air mixing quality and further combustion performance. In this study, two cases of combustion chamber structure formed by one-cut and four-cut processing methods respectively were studied. 3-D CFD was a convenient and cheap tool to explore effects of these two styles of cylinder head on the combustion process. This work was done on the ESE Engine module of commercial CFD software AVL FIRE and operated by comparisons of these two cases on the development of swirl ratio, equivalence ratio distribution and combustion characteristics.
2017-03-28
Technical Paper
2017-01-0847
Ming Ge, Xingyu Liang, Hanzhengnan Yu, Yuesen Wang, Hongsheng Zhang
Spray impacting on a lube oil film with a finite thickness is a common phenomenon in IC engines and plays a critical role in the fuel-air mixture process and combustion. With the use of early injection strategy to achieve HCCI combustion mode in diesel engines, this phenomenon becomes more and more prominent. In addition, oxygenated fuels such as methanol and ethanol are regarded as alternative fuel and additives to improve the overall performance of HCCI engine. Therefore, a better understanding about the role of lube oil film thickness in methanol-diesel and ethanol-diesel blended fuels spray/wall impingement is helpful for accumulating experimental data to establish a more accurate spray/wall impingement model and optimize the combustion in HCCI engines. In this paper, the effect of lube oil film thickness on the characteristics of spray/wall impingement of different fuels are investigated in a constant volume bomb test system.
2017-03-28
Technical Paper
2017-01-0964
Jakob Heide, Mikael Karlsson, Mireia Altimira
Selective Catalytic Reduction (SCR) of NOx through injection of Urea-Water-Solution (UWS) into the hot exhaust gas stream is an effective and extensively used strategy in internal combustion engines. Even though actual SCR systems have 95-96% de-NOx efficiency over test cycles, real driving emissions of NOx are much higher, hence proving that there is room for improvement. The efficiency of the NOx conversion is highly dependent on the size of UWS droplets and their spatial distribution. These factors are, in turn, mainly determined by the spray characteristics and its interaction with the exhaust gas flow. The main purpose of this study is to numerically investigate the sensitivity to the modelling framework of the evaporation and mixing of the spray upstream of the catalyst. The dynamics of discrete droplets is handled through the Lagrangian Particle Tracking framework, with models that account for droplet breakup and coalescence, turbulence effects, and water evaporation.
2017-03-28
Technical Paper
2017-01-0708
Carlos Jorques Moreno, Ola Stenlaas, Per Tunestal
Factors influencing the pilot-injection combustion, the effect of pilot-injection on main-injection combustion, performance and emissions were investigated by heat release analysis in a heavy duty diesel engine fueled with standard diesel fuel. Combinations of pilot injection parameters i.e. pilot start of injection, pilot mass, pilot-main injection separation and rail pressure were studied for the different operating conditions and combustion phases. The factors influencing the pilot combustion and its impact on the main injection were investigated. It was concluded that the effect of pilot-injection combustion on main injection depends on during which phase of pilot combustion main injection starts.
2017-03-28
Technical Paper
2017-01-0713
Håkan Persson, Aristotelis Babajimopoulos, Arjan Helmantel, Fredrik Holst, Elin Stenmark
To fulfill the demands for a future diesel engine in terms of Emission compliance, CO2 emissions, performance and cost effectiveness also sets new requirements for the development process. This paper focuses on the development of the diesel combustion system to comply with Euro 6d including real driving conditions (RDE) with emphasis on the novel methods applied throughout the process. The foundation of a high performing system is formed by first determining the requirements for the system, after which the key factors that affect system performance are selected. Based on the requirements a robust charge motion with desired flow characteristics is defined. Then, a new effective automated direct driven Combustion CFD optimization for combustion chamber and spray is developed. From the simulation pareto fronts, the best hardware solutions are selected. These candidates are selected with different attributes.
2017-03-28
Technical Paper
2017-01-0791
Konstantinos Siokos, Zhizhen He, Robert Prucka
Knock-limited engine operation is one of the most important constraints on fuel efficiency and performance that must be considered during the design, control algorithm development and calibration of spark-ignition engines. Since a complete fundamental explanation of knock phenomenon over the full range of engine conditions is not available, estimating knock onset at different in-cylinder thermodynamic conditions is very challenging. Various approaches have been proposed, either stochastic or deterministic, in an effort to capture the complex phenomena related to engine knock for the purposes of engine control. This research evaluates the accuracy of control-oriented physics-based knock prediction routines under various engine operating conditions. Two common methods of knock prediction, a generalized chemical kinetics model and an induction-time integral, are evaluated and compared against experimental data.
2017-03-28
Technical Paper
2017-01-0666
Zhenbiao Zhou, Yi Yang, Michael Brear, Joshua Lacey, Thomas G. Leone, James E. Anderson, Michael H. Shelby
Autoignition in modern spark ignition (SI) engines occurs at different conditions to those in the standardized Research (RON) and Motor (MON) Octane Number tests. The Octane Index (OI) has been proposed to account for these differences, with OI=RON–K(RON-MON) related to the occurrence of knock in the modern engine by several methods. The so-called K value then quantifies the deviation of the modern engine operation from the standard RON and MON tests. This paper presents a comparison of different methods for calculating the K value for the same modern engine operating with direct injection (DI), port fuel injection (PFI) and homogeneous, upstream fuel injection (UFI). The test fuels used span a wide range of RONs and fuel sensitivities (S=RON-MON). The quality of the results obtained using some of these methods were particularly dependent on the design of the test fuel matrix, with unreliable K values resulting in some cases.
2017-03-28
Technical Paper
2017-01-0141
Ray Host, Peter Moilanen, Marcus Fried, Bhageerath Bogi
Future vehicle North American emissions standards (e.g., North American SULEV 30) require the exhaust catalyst to be >80% efficient by 20 seconds after the engine has been started in the Federal Test Procedure. Turbocharged engines are especially challenged to deliver fast catalyst lightoff since the presence of the turbocharger in the exhaust flow path significantly increases exhaust system heat losses. A solution to delivering cost effective SULEV30 emissions in turbocharged engines is to achieve fast catalyst light-off by reducing exhaust system heat losses in cold start, without increasing catalyst thermal degradation during high load operation. A CAE methodology to assess the thermal performance of exhaust system hardware options, from the exhaust port to the catalyst brick face is described, which assures compliance with future emissions regulations.
2017-03-28
Technical Paper
2017-01-0632
Chen Yang, Haiyuan Cheng, Zizhu fan, Jiandong Yin, Yuan Shen
In recent years, more attention has been focused on environment pollution and energy source issues. As a result, increasingly stringent fuel consumption and emission legislations have been implemented all over the world. For automakers, enhancing engine’s efficiency as a must contributes to lower vehicle fuel consumption. To reach this goal, Geely auto started the development of a 3-cylinder 1.0L turbocharged direct injection (TGDI) gasoline engine to achieve a challenging fuel economy target while maintaining fun-to-drive and NVH performance. Demanding development targets for performance (specific torque 205Nm/L and specific power 100kW/L) and excellent part-load BSFC were defined, which lead to a major challenge for the design of engine systems, especially for combustion system.
2017-03-28
Technical Paper
2017-01-1052
Paul Zeng, Vincent Solferino, Mark Stickler
Engine ticking noise is one of the key failure modes in today’s direct injection (DI) engines. High ticking noise results in high Things Gone Wrong (TGW) index, which negatively affects customer satisfaction. In this paper, the root cause of the ticking noise from DI injector in direct mounting will be presented. Design principle such as injector impact force to cylinder head and DI injector isolator design with 2 stage stiffness is proposed.
2017-03-28
Technical Paper
2017-01-0719
Martin Muinos, Valentin Soloiu, Jose Moncada, Remi Gaubert, Gustavo Molina, Johnnie Williams
In this study, the combustion and emissions characteristics of n-butanol/GTL and n-butanol/ultra-low sulfur diesel (ULSD) blends are compared in a single-cylinder experimental diesel engine. The n-butanol was blended with a Fischer-Tropsch (FT) gas-to-liquid (GTL) fuel, at 25% and 50% mass. N-butanol was also blended with ULSD at the same mass ratios. FT fuels are an attractive alternative to petroleum based fuels because they can be used as a drop-in fuel with existing infrastructure. N-butanol is renewable fuel capable of being produced from waste biomass sources. The investigations were conducted at 1500 rpm and three loads of 2.75, 4.75, and 6.75 IMEP, representative for the research engine. 15% exhaust gas recirculation was utilized along with a supercharger to increase the intake pressure to 1.2 bar absolute. Neat ULSD and GTL, respectively, were investigated as a baseline.
2017-03-28
Technical Paper
2017-01-0645
Jeremy Galpin, Thierry Colliou, Olivier Laget, Fabien Rabeau, Gaetano De Paola, Pascal Rahir
In spite of the increasingly stringent emission standards, the constant growth of road traffic contributes to climate change and induces detrimental effects on the environment. The European REWARD project (REal World Advanced Technologies foR Diesel Engines) aims to develop a new generation of Diesel engines complying with stricter post Euro 6 legislation and with lower CO2 emissions. Among the different technologies developed, a fuel-efficient two-stroke Diesel engine suited for C-segment passenger cars will be designed and experimentally evaluated. One major challenge for two-stroke engines is the achievement of an efficient scavenging. As the emptying of the in-cylinder burnt gases and the filling by fresh gases is performed in the same time, the complexity consists in removing as much as burnt gases as possible while avoiding the by-pass of fresh air toward the exhaust line.
2017-03-28
Technical Paper
2017-01-1248
Ming Su, Chingchi Chen, Krishna Prasad Bhat, Jun Kikuchi, Shrivatsal Sharma, Thomas Lei
Due to global trends and government regulations for CO2 emission reduction, the automotive industry is actively working toward vehicle electrification to improve fuel efficiency and minimize tail-pipe pollutions. For the traction inverter systems in today’s hybrid electric vehicles (HEV), silicon IGBTs and power diodes are the main control devices. These mature components are reliable and cost-effective, but have their limitation on energy losses. SiC wide bandgap semiconductor, on the other hand, has potential to offer additional boost of efficiency for the HEV drive system. In recent years, commercial SiC MOSFETs are significantly improved in terms of conduction and switching losses. However, reliability concerns and high prices still place a limit on their overall competitiveness against silicon. Ford Motor Company has partnered with major semiconductor manufacturers to evaluate SiC products for the HEV inverter system.
2017-03-28
Technical Paper
2017-01-0682
Yuedong Chao, Haifeng Lu, Zongjie Hu, Jun Deng, Zhijun Wu, Liguang Li, Yuan Shen, Shuang Yuan
In this paper comparisons were made between the fuel economy improvement by a High Pressure (HP) water-cooled Exhaust Gas Recirculation (EGR) system and that by a Low Pressure (LP) water-cooled EGR system. Experiments were implemented on a 1.3-Litre turbocharged PFI gasoline engine from 1500rpm to 3000rpm and BMEP from 2bar to 14bar because of the relative narrow available range of HP-EGR system. In consideration of practical application of EGR system, the coolant used in this experiment was kept almost the same temperature as in real vehicles (88±3℃) instead of underground water temperature. The results indicated that, HP-EGR usually got higher best EGR rates for fuel economy at low-load region, and a better improvement (up to 2.96%) of fuel economy was expected. In contrast at moderate-to-high loads, especially at low speed high load region, HP-EGR rates were severely constrained by the application of turbo.
2017-03-28
Technical Paper
2017-01-1640
Peng Liu, Liyun Fan, Wenbo Peng, Xiuzhen Ma, Enzhe Song
A novel high-speed electromagnetic actuator for electronic fuel injection system of diesel engine is proposed in this paper. By using permanent magnet and annular flange, the design of novel actuator aims to overcome the inherent drawbacks of the conventional solenoid electromagnetic actuator, such as high power consumption and so on. The finite element model (FEM) of novel actuator is developed. Combined with design of experiments and finite element analysis, the second order polynomial response surface models (RSM) of electromagnetic force of novel actuator are produced by the least square principle. Then the influence mechanisms and interaction effects of key design variables on the electromagnetic characteristics of novel actuator are revealed by RSM.
2017-03-28
Technical Paper
2017-01-0846
Raul Payri, Gabriela Bracho, Pedro Marti-Aldaravi, Alberto Viera
In the present work a constant-pressure flow facility able to reach 15 MPa ambient pressure and 1000K ambient temperature has been employed to carry out experimental studies of the combustion process at Diesel-like conditions. The objective is to characterize the influence of boundary conditions on OH* and broadband chemiluminiscence intensity generated by the fuel combustion for passenger car and heavy duty diesel injectors. Three nozzle types were investigated: a spray B nozzle (diameter of 90um) and two heavy duty application nozzles (diameter of 194 um and 228 um respectively). The results showed that nozzle size have a substantial impact on the ignition event, affecting the premixed phase of the combustion and the ignition location. Concerning OH, for the small nozzle geometry (Spray B) the ECN standard methodology was applied; meanwhile, for bigger nozzles a different processing method is proposed based on intensity threshold criteria.
Viewing 1 to 30 of 43636