Criteria

Text:
Sector:
Display:

Results

Viewing 108331 to 108360 of 110426
2017-03-28
Journal Article
2017-01-0799
Arjun Prakash, Chongming Wang, Andreas Janssen, Allen Aradi, Roger Cracknell
Modern spark ignition engines can take advantage of better fuel octane quality either towards improving acceleration performance or fuel economy via an active ignition management system. Higher fuel octane allows for spark timing advance and consequently higher torque output and higher engine efficiency. Additionally, engines can be designed with higher compression ratios if a higher anti-knock quality fuel is used. Due to historical reasons, Research Octane (RON) and Motor Octane Number (MON) are the metrics used to characterize the anti-knock quality of a fuel. The test conditions used to compute RON and MON correlated well with those in older engines designed about 20 years ago. But the correlation has drifted considerably in the recent past due to advances in engine infrastructures mainly governed by stringent fuel economy and emission standards.
2017-03-28
Technical Paper
2017-01-0890
Yoichiro Nakamura, Masahisa Horikoshi, Yasunori TAKEI, Takahiro Onishi, Yasuhiro Murakami, Chip Hewette
Abstract Heavy duty vehicles take a large role in providing global logistics. It is required to have both high durability and reduced CO2 from the viewpoint of global environment conservation. Therefore lubricating oils for transmission and axle/differential gear box are required to have excellent protection and longer drain intervals. However, it is also necessary that the gear oil maintain suitable friction performance for the synchronizers of the transmission. Even with such good performance, both transmission and axle/differential gear box lubricants must balance cost and performance, in particular in the Asian market. The development of gear oil additives for high reliability gear oil must consider the available base oils in various regions as the additive is a global product. In many cases general long drain gear oils for heavy duty vehicles use the group III or IV base oils, but it is desirable to use the group I/II base oils in terms of cost and availability.
2017-03-28
Journal Article
2017-01-0891
Gregory Hunt
Abstract Modern automotive transmissions contain copper and copper alloys in the form of washers, bushings, brazes and electrical components. Corrosion that occurs with any of these components especially with electrical contacts can result in a malfunction of the vehicle control systems and loss of vehicle drivability. The compatibility of transmission lubricants with copper and copper alloys is an increasingly important consideration in the design of new additive technology. Traditional methods for monitoring corrosion processes and mechanisms in real time can be both time consuming and challenging to interpret, especially when evaluations at multiple temperatures are required. This work challenges some of the industry-held beliefs around lubricant additive corrosion processes, especially at elevated temperature (>130 °C).
2017-03-28
Journal Article
2017-01-0939
Ashok Kumar, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Abstract Copper- and Iron- based metal-zeolite SCR catalysts are widely used in US and European diesel aftertreatment systems to achieve drastic reduction in NOx emission. These catalysts are highly selective to N2 under wide range of operating conditions. Nevertheless, the type of transition metal has a significant impact on the key performance and durability parameters such as NOx conversion, selectivity towards N2O, hydrothermal stability, and sensitivity to fuel sulfur content. In this study, we explained the differences in the performance characteristics of these catalysts based on their relative acidic-basic nature of transition metal present in these catalysts using practically relevant gas species present in diesel exhaust such as NO2, SOx, and NH3. These experiments show that Fe-zeolite has relatively acidic nature as compared to Cu-zeolite that causes NH3 inhibition and hence explains low NOx conversion on Fe-zeolite at low temperature under standard SCR conditions.
2017-03-28
Journal Article
2017-01-0910
Michiel Makkee, Yixiao Wang
Abstract We studied the mechanism of NO reduction as well as its selectivity and reactivity in the presence of excess O2. Results show that fuel injection and/or pretreatment are important for ceria catalyst reduction and carbon deposition on the catalyst surface. Oxygen defects of reduced ceria are the key sites for the reduction of NO into N2. The deposited carbon acts as a buffer reductant, i.e., the oxidation of carbon by lattice oxygen recreates oxygen defects to extend the NO reduction time interval. A small amount of NO showed a full conversion into only N2 both on the reduced Zr-La doped ceria and reduced Pt-Zr-La doped ceria. Only when the catalyst is oxidised NO is converted into NO2.
2017-03-28
Technical Paper
2017-01-0886
Liyan Feng, Ximing DI, Wuqiang LONG, Yao Wu, Chao Liu, Hang Lv
Abstract The combustion of cylinder lubricating oil (called as cylinder oil for short) is one of the major sources of PM emissions of low-speed 2-stroke marine diesel engines. For pre-mixed combustion low-speed 2-stroke marine gas engines, the auto-ignition of cylinder oil might result in knock or more hazard abnormal combustion - pre-ignition. Evaporation is a key sub-process of the auto-ignition process of cylinder oil droplets. The evaporation behavior has a profound impact on the auto-ignition and combustion processes of cylinder oil droplets, and a great influence on engine combustion performance and emission characteristics. This paper applied an oil suspending apparatus to investigate the evaporation behavior of cylinder oil droplets and base oil droplets. The effects of ambient temperatures on the evaporation process were measured and analyzed. The results indicate that the evaporation of cylinder oil includes heating, evaporating, pyrolysis, and polymerization.
2017-03-28
Journal Article
2017-01-0884
Ken Hashimoto, Kenji Tomizawa, Yoichiro Nakamura, Takashi Hashimoto, Takahiro Tatani, Atsushi Akamatsu, Ryuji Aoki, JASO Diesel Engine Oil Standard Revision Task Force
Abstract This paper reviews the development of the first fuel economy engine test method for heavy duty diesel oil, as well as the new JASO DH-2F category introduced in April 2017 [1][2][3], which adds a fuel economy requirement to the JASO DH-2 requirements in the JASO M355:2015 standard. Recently, better fuel economy is required heavy duty diesel vehicles as well as gasoline vehicles. Therefore, advanced technologies have been applied to improve diesel engines, as well as diesel engine oils and additives, and achieve better fuel economy. However, the Automotive Diesel Engine Oil Standard (JASO M355) applied in Japan as a standard for diesel engine oils does not include any fuel economy requirements.
2017-03-28
Technical Paper
2017-01-0888
Prashant Kumar, Reji Mathai, Sanjeev KUMAR, Ashish Kachhawa, Ajay Kumar Sehgal, Snigdhamayee Praharaj
Abstract The growing transportation sector worldwide has opened up a way forward not only for the scientists & researchers but also for the OEMs to find out the options for fuel efficient automotive vehicles with reduced emissions during their usage. The demand of automotive vehicles has been doubled in last few years and in turn the market for lubricants and transmission fluids are flourishing. Several new formulations of lubricants are getting popularized with major suppliers to achieve the end user expectations in terms of fuel economy benefits, engine life and emissions. The market trend is continuously moving towards the improvement in lubricant formulation to the lower viscosity ranges and in this direction several companies are into development of multi-grade low viscosity range of engine oils (lubricants) which is said to be providing the benefits in terms of fuel economy.
2017-03-28
Journal Article
2017-01-0889
Adam Brandt, Allen Comfort, Edwin Frame
Abstract For existing fleets such as the U.S. military ground vehicle fleet, there are few ways to reduce vehicle fuel consumption that don’t involve expensive retrofitting. Replacing standard lubricants with those that can achieve higher vehicle efficiencies is one practical and inexpensive way to improve fleet fuel efficiency. In an effort to identify axle gear lubricants that can reduce the fuel consumption of its fleet, the U.S. Army is developing a stationary axle efficiency test stand and procedure. In order to develop this capability, on-track vehicle fuel consumption testing was completed using light, medium, and heavy tactical wheeled vehicles following a modified SAE J1321 type test procedure. Tested lubricants included a baseline SAE 80W-90, a fuel efficient SAE 75W-90, and a fuel efficient SAE 75W-140. Vehicle testing resulted in reductions in fuel consumption of up to 2%.
2017-03-28
Technical Paper
2017-01-1036
Silvia Marelli, Simone Gandolfi, Massimo Capobianco
Abstract In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on turbine performance. An experimental investigation on a small turbocharger for automotive application has been carried out and presented. The study focused onto the effects of internal heat transfer on turbine thermomechanical efficiency. The experimental campaign was developed considering the effect of different heat transfer state by varying turbine inlet temperature, oil and coolant temperature and compressor inlet pressure. An original model previously developed by the Authors is adopted for the correction of compressor steady flow maps.
2017-03-28
Journal Article
2017-01-1046
Christian Binder, Fahed Abou Nada, Mattias Richter, Andreas Cronhjort, Daniel Norling
Abstract Diesel engine manufacturers strive towards further efficiency improvements. Thus, reducing in-cylinder heat losses is becoming increasingly important. Understanding how location, thermal insulation, and engine operating conditions affect the heat transfer to the combustion chamber walls is fundamental for the future reduction of in-cylinder heat losses. This study investigates the effect of a 1mm-thick plasma-sprayed yttria-stabilized zirconia (YSZ) coating on a piston. Such a coated piston and a similar steel piston are compared to each other based on experimental data for the heat release, the heat transfer rate to the oil in the piston cooling gallery, the local instantaneous surface temperature, and the local instantaneous surface heat flux. The surface temperature was measured for different crank angle positions using phosphor thermometry.
2017-03-28
Journal Article
2017-01-1018
Gianluca Padula, Philipp Schiffmann, Matthieu Lecompte, Olivier Laget
Abstract Ever growing traffic has a detrimental effect on health and environment. In response to climate warming and health concerns, governments worldwide enforce more stringent emission standards. NOx emissions limits are some of the most challenging to meet using fuel-efficient lean-burn engines. The Selective Catalytic Reduction (SCR) is one consolidated NOx after-treatment technique using urea water solution (UWS) injection upstream of the catalytic converter. A recent development of SCR, using gaseous ammonia injection, reduces wall deposit formation and improves the cold-start efficiency. The mixing of gaseous ammonia with the exhaust gases is one of the key challenges that need to be overcome, as the effectiveness of the system is strongly dependent on the mixture uniformity at the inlet of the SCR catalyst.
2017-03-28
Technical Paper
2017-01-1026
Richard Morton, Romain Riviere, Stephen Geyer
Abstract A study of the crank and gear-train dynamics of a two-stroke opposed piston diesel engine design uncovered a disconnect between the thermodynamic process and its conversion to mechanical work. The classic two-stroke opposed piston design phases the intake piston to lag the exhaust piston in order to achieve favorable gas exchange, overcoming the disadvantage of piston-controlled ports. One result of this is that significantly more of the engine torque is delivered by the leading crank than from the trailing one. This paper will examine why this torque difference occurs showing that it is not simply a proportioning of the available thermodynamic work but a result of a fundamental mechanical loss mechanism that limits the achievable brake efficiency of this engine architecture. This analysis will provide a basis for developing effective design solutions to overcome the mechanical loss by providing an understanding of this loss mechanism.
2017-03-28
Journal Article
2017-01-0953
Jinyong Luo, Yadan Tang, Saurabh Joshi, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Abstract Cu/CHA catalysts have been widely used in the industry, due to their desirable performance characteristics including the unmatched hydrothermal stability. While broadly recognized for their outstanding activity at or above 200°C, these catalysts may not show desired levels of NOx conversion at lower temperatures. To achieve high NOx conversions it is desirable to have NO2/NOx close to 0.5 for fast SCR. However even under such optimal gas feed conditions, sustained use of Cu/CHA below 200°C leads to ammonium nitrate formation and accumulation, resulting in the inhibition of NOx conversion. In this contribution, the formation and decomposition of NH4NO3 on a commercial Cu/CHA catalyst have been investigated systematically. First, the impact of NH4NO3 self-inhibition on SCR activity as a function of temperature and NO2/NOx ratios was investigated through reactor testing.
2017-03-28
Journal Article
2017-01-1017
Michael Rößler, Amin Velji, Corina Janzer, Thomas Koch, Matthias Olzmann
Abstract The proportion of nitrogen dioxide in the engine-out emissions of a Diesel engine is of great importance for the conversion of the total oxides of nitrogen (NOX) emissions in SCR catalysts. Particularly at lower engine loads and lower exhaust temperatures an increase of the already low NO2/NOX fraction will enhance the SCR operation significantly. For this purpose, the understanding of the NO2 formation during the Diesel combustion and expansion stroke is as substantial as being aware of the different thermodynamic impacts and engine operating parameters that affect the formation process. To determine the influences on the NO2 emission level several variation series were performed on a single-cylinder research engine. Especially the charge dilution parameters like the air-fuel ratio and the EGR rate as well as the injection parameters could be identified to be decisive for the NO2 formation.
2017-03-28
Technical Paper
2017-01-0943
Cory S. Hendrickson, Devesh Upadhyay, Michiel Van Nieuwstadt
Abstract Over the past decade urea-based selective catalytic reduction (SCR) has become a leading aftertreatment solution to meet increasingly stringent Nitrogen oxide (NOx) emissions requirements in diesel powertrains. A common trend seen in modern SCR systems is the use of "split-brick" configurations where two SCR catalysts are placed in thermally distinct regions of the aftertreatment. One catalyst is close-coupled to the engine for fast light-off and another catalyst is positioned under-floor to improve performance at high space velocities. Typically, a single injector is located upstream of the first catalyst to provide the reductant necessary for efficient NOx reduction. This paper explores the potential benefit, in terms of improved NOx reduction, control of NH3 slip or reduced reductant consumption, of having independently actuated injectors in front of each catalyst.
2017-03-28
Technical Paper
2017-01-0944
Ryuji Ando, Takashi Hihara, Yasuyuki Banno, Makoto Nagata, Tomoaki Ishitsuka, Nobuyuki Matsubayashi, Toshihisa Tomie
Abstract Modern diesel emission control systems often use Urea Selective Catalytic Reduction (Urea-SCR) for NOx control. One of the most active SCR catalysts is based on Cu-zeolite, specifically Cu-Chabazite (Cu-CHA), also known as Cu-SSZ-13. The Cu-SCR catalyst exhibits high NOx control performance and has a high thermal durability. However, its catalytic performance deteriorates upon long-term exposure to sulfur. This work describes our efforts to investigate the detailed mechanism of poisoning of the catalyst by sulfur, the optimum conditions required for de-sulfation, and the recovery of catalytic activity. Density functional theory (DFT) calculations were performed to locate the sulfur adsorption site within the Cu-zeolite structure. Analytical characterization of the sulfur-poisoned catalyst was performed using Extreme Ultraviolet Photoelectron Spectroscopy (EUPS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS).
2017-03-28
Technical Paper
2017-01-1109
Keisuke Ota, Masami Kondo, Shuntaro Shinohara, Norihiro Tsukamoto, Seiji Masunaga, Ayumu Sagawa
Abstract To meet increasing driveability expectation and government stringent fuel economy regulations reducing CO2 emissions of passenger cars; Toyota developed a new 8-speed automatic transmission "Direct Shift-8AT". Direct Shift-8AT is the first stepped automatic transmission model based on “TNGA” philosophy. New models which received Direct Shift-8AT are the new Camry, Highlander and Sienna. Direct Shift-8AT has an innovative control method with gear train and torque converter models, providing enhanced driveability and fuel economy performance through high efficiency transmission technology. This paper describes details of the new technology and vehicle performance.
2017-03-28
Journal Article
2017-01-1168
Zheng Liu, Walter J. Ortmann, Bernard Nefcy, Dan Colvin, Francis Connolly
Abstract In Hybrid Electric Vehicles, Regenerative Braking is an essential function to convert vehicle kinetic energy into electrical energy, which charges the battery during a braking event to make a portion of captured kinetic energy available for use later. In comparison, conventional vehicles use friction brakes only and kinetic energy is dissipated as heat and not made available for later use. This paper introduces methods of evaluating Regenerative Braking Efficiency, including multiple efficiency definitions that lead to different attributes. The paper proposes regenerative brake event definitions during the FTP cycle and how they are used for control strategy and calibration updates. Also, we apply the efficiency metrics to four different vehicles from four automotive manufacturers for comparison. The paper presents a sample comparison result.
2017-03-28
Technical Paper
2017-01-1091
Todd Brewer, Xingfu Chen
Abstract Typically, modern automotive engine designs include separate cylinder heads and cylinder blocks and utilize a multilayer steel head gasket to seal the resulting joint. Cylinder head bolts are used to hold the joint together and the non-linear properties of head gasket provide capability to seal the movement within the joint, which is essential for engine durability and performance. There are three major failure modes for head gasket joint: fluid or gas leakage due to low sealing pressure, head gasket bead cracking due to high gap alternation and scrubbing/fretting due to pressure and temperature fluctuations causing lateral movement in the joint. During engine operation, the head gasket design should be robust enough to prevent all three failure modes and the resulting design must consider all three major failure modes to provide acceptable performance.
2017-03-28
Technical Paper
2017-01-1093
Yosuke Michikoshi, Daisuke Kusamoto, Hirofumi Ota, Masashi Ikemura, Noritaka Takebayashi, Ike Nobukazu, Yasuda Takashi, Inoue Ryohei
Abstract The new eight-speed automatic transmission direct shift-8AT (UA80) is the first automatic transmission to be developed based on the Toyota New Global Architecture (TNGA) design philosophy. Commonizing or optimizing the main components of the UA80 enables compatibility with a wide torque range, including both inline 4-cylinder and V6 engines, while shortening development terms and minimizing investment. Additionally, it has superior packaging performance by optimizing the transmission size and arrangement achieving a low gravity center. It contributes to Vehicle’s attractiveness by improving driving performance and NVH. At the same time, it drastically improves fuel economy and quietness.
2017-03-28
Technical Paper
2017-01-1065
Douglas R. Martin, Benjamin Rocci
Abstract Exhaust temperature models are widely used in the automotive industry to estimate catalyst and exhaust gas temperatures and to protect the catalyst and other vehicle hardware against over-temperature conditions. Modeled exhaust temperatures rely on air, fuel, and spark measurements to make their estimate. Errors in any of these measurements can have a large impact on the accuracy of the model. Furthermore, air-fuel imbalances, air leaks, engine coolant temperature (ECT) or air charge temperature (ACT) inaccuracies, or any unforeseen source of heat entering the exhaust may have a large impact on the accuracy of the modeled estimate. Modern universal exhaust gas oxygen (UEGO) sensors have heaters with controllers to precisely regulate the oxygen sensing element temperature. These controllers are duty cycle based and supply more or less current to the heating element depending on the temperature of the surrounding exhaust gas.
2017-03-28
Technical Paper
2017-01-1075
Wen Chen, Reda Adimi, Xingfu Chen, Todd Brewer, Ling Shi
Abstract In CAE analysis of cylinder bore distortion, valve seat distortion, valve guide-to-seat misalignment and cam bore misalignment, nodal displacements on the cylinder bore inner surface and on the gage lines of valve seats, valve guides and cam bores are typically output. Best fit cylinders, best fit circles and best fit lines are computed by utilizing the output displacements of the deformed configuration. Based on the information of the best fit geometry, distortions and misalignments are assessed. Some commercial and in-house software is available to compute the best fit cylinders, best fit circles and best fit lines. However, they suffer from the drawback that only one best-fit geometry can be computed at a time. Using this kind of software to assess distortions and misalignments of engine components would be tedious and prone to error, since data transfer as well as the intermediate computation has to be done by hand, and the process is not automatic.
2017-03-28
Journal Article
2017-01-1053
Satoshi Watanabe, Yuji Miyata, Yosuke Ogata, Vincent Ivosic
Abstract Idling stop systems are being increasingly adopted in conventional engine vehicles as well as hybrid electric vehicles to increase fuel efficiency. When the engine starts, body vibration occurs that is caused by the rigid body eigenvalues of the power plant during initial combustion. Engine restart vibration after an idling stop is caused by the input force from the transmission, and the reaction force from the drive shaft as well as the input force from the engine. This phenomenon occurs frequently when the engine is restarted from the idling stop, the vibration is increasingly annoying to passengers. Usually, the vehicle development process is carried out in accordance with the V process. The V process divides the vehicle development process into two stages. The first stage is called the vehicle design stage to determine the characteristic. The second stage is called the vehicle verification stage to verify the performance.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya Marri, Simon Antonov
Abstract In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to enable reduction in friction and delivery of stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during oil pump shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise, different porting geometries and vane spacing are used. This paper describes an optimization method intended to identify the best possible spacing of the vanes in the conventional 7-vanes, 9-vanes and 11-vanes oil pumps. The method integrates a Matlab routine with the modeFRONTIER software to create the required design space in order to perform a multi-objective optimization using a genetic algorithm. Results of this optimization method are discussed and a design guideline for the VDOP vane spacing is disclosed.
2017-03-28
Technical Paper
2017-01-1284
Khushal Ahmad, Monis Alam
Abstract With the ever increasing number of vehicles on road and the rise of the electric and automated vehicles, it is important to minimize the consumption of energy by each vehicle, regenerative braking is in wide use today, however, the research in the field of regenerative suspension is limited. The regenerative suspension has huge capabilities in power generation especially on third world roads having rather bumpy rides. A huge amounts of energy is wasted in shock absorbers due to friction. This study emphasizes on the implementation of the energy present in the suspension system by replacing the Shock Absorber with a Energy transfer system Involving Hydraulic cylinder, Hydraulic Motor and Dynamo. The energy which is usually lost as heat due to friction in conventional Suspension is used to drive a dynamo through Hydraulic System designed in this paper and electricity is generated.
2017-03-28
Technical Paper
2017-01-1258
John Catton, Caixia Wang, Steven Sherman, Michael Fowler, Roydon Fraser
Abstract The automobile industry has been undergoing a transition from fossil fuels to a low emission platform due to stricter environmental policies and energy security considerations. Electric vehicles, powered by lithium-ion batteries, have started to attain a noticeable market share recently due to their stable performance and maturity as a technology. However, electric vehicles continue to suffer from two disadvantages that have limited widespread adoption: charging time and energy density. To mitigate these challenges, vehicle Original Equipment Manufacturers (OEMs) have developed different vehicle architectures to extend the vehicle range. This work seeks to compare various powertrains, including: combined power battery electric vehicles (BEV) (zinc-air and lithium-ion battery), zero emission fuel cell vehicles (FCV)), conventional gasoline powered vehicles (baseline internal combustion vehicle), and ICE engine extended range hybrid electric vehicle.
2017-03-28
Journal Article
2017-01-1249
Masahiro Seguchi
Abstract Compact, high efficiency and high reliability are required for an xEV motor generator. IPM rotors with neodymium magnets are widely applied for xEV motors to achieve these requirements. However, neodymium magnet material has a big impact on motor cost and there is supply chain risk due to increased usage of these rare earth materials for future automotive xEV’s. On the other hand, a wound-field rotor does not need magnets and can achieve equivalent performance to an IPM rotor. However, brushes are required in order to supply current to the winding coil of the rotor. This may cause insulation issues on xEV motors which utilize high voltage and high currents. Therefore, it is suggested to develop a system which supplies electric energy to the rotor field winding coil from the stator without brushes by applying a transformer between stator coil and rotor field winding. Specifically, add auxiliary magnetic poles between each field winding pole and wind sub-coils to these poles.
2017-03-28
Technical Paper
2017-01-1237
Ahmad Arshan Khan, Michael J. Kress
Abstract For high performance motor controls applications such as electric vehicles, accurate motor parameter knowledge is required. Motor parameters like d-axis inductance, q-axis inductance, resistance and permanent magnet flux linkage are difficult to obtain and measure directly. These four parameters can be reduced to three parameters resistance, d-axis and q axis flux linkage. In this paper, a new scheme is proposed to approximate d-axis and q-axis flux linkage using measured torque, dq-axis measured current, and dq-axis voltage commands to the inverter. d-axis and q-axis flux linkages are estimated over a range of d-axis and q-axis currents that fully map the desired motor operation region.

Filter

  • Range:
    to:
  • Year: