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Viewing 121 to 150 of 16434
2017-03-28
Technical Paper
2017-01-1088
Katherine Randall, Cody Bradford, Jeremy Ross, Jeremy Church, Nolan Dickey, Adam Christian, Matthew Dunn
Abstract High frequency variations in crankcase pressure have been observed in Inline-four cylinder (I4) engines and an understanding of the causes, frequency and magnitude of these variations is helpful in the design and effective operation of various engine systems. This paper shows through a review and explanation of the physics related to engine operation followed by comparison to measured vehicle data, the relationship between crankcase volume throughout the engine cycle and the observed pressure fluctuations. It is demonstrated that for a known or proposed engine design, through knowledge of the key engine design parameters, the frequency and amplitude of the cyclic variation in crankcase pressure can be predicted and thus utilized in the design of other engine systems.
2017-03-28
Technical Paper
2017-01-0382
Oscar Hernandez Cervantes, Antonio Espiritu Santo Rincon
Abstract The development of an automatic control system for a towing dynamometer used for testing is described in this paper. The process involved the deployment of new power electronics circuit boards, a TELMA retarder, instrumentation and a human machine interface (HMI) achieved through an open source platform. The purpose of this platform is to have a low cost system that allows further function development, data acquisition and communication with other devices. This system is intended as a novel solution that will allow closed loop and automated tests integrated with PCM data for engine calibration. It is projected to be part of a flexible calibration system with direct communication to the interfaces used during development (ATI, ETAS), which will be used to achieve lean test and development schedules.
2017-03-28
Technical Paper
2017-01-0699
Sampad Mukhopadhyay, Sunil Srinivas Badavath, Naeim Henein
Abstract The superior fuel economy of direct injection internal combustion engines (diesel and gasoline) is related to use of a high compression ratio to auto-ignite the fuel and the overall lean combustible mixture. Two of the major problems in diesel engine emissions are the NOx and soot emissions, which are caused by the heterogeneity of the charge and the properties of the diesel fuel. Conventional Direct Injection Spark Ignition Gasoline engines don't have these problems because of the fuel properties particularly its volatility. However, its efficiency and specific power output are limited by the knock, knock produced preignition and the sporadic preignition phenomenon. The Gasoline Direct Injection Compression Ignition (GDICI) engine combines the superior features of the two engines by increasing the compression ratio and use of gasoline as a fuel.
2017-03-28
Technical Paper
2017-01-0519
Maziar Khosravi, Aadinath Harihar, Heinz Pitsch, Carsten Weber
Abstract The performance of modern boosted gasoline engines is limited at high loads by knock, stochastic Low Speed Pre-Ignition as well as megaknock. The main objective of the present work is to develop a predictive combustion model to investigate auto-ignition and megaknock events at high load conditions in gasoline engines. A quasi one-dimensional combustion simulation tool has been developed to model abnormal combustion events in gasoline engines using detailed chemical kinetics and a multi zone wall heat transfer model. The model features six boundary layers representing specific geometrical features such as liner and piston with individual wall temperatures and chemistry to accurately track the individual zone’s thermodynamic properties. The accuracy of the utilized auto-ignition and one-dimensional spark ignition combustion models was demonstrated by validating against experimental data.
2017-03-28
Technical Paper
2017-01-0817
Remi Konagaya, Ken Naitoh, Kohta TSURU, Yasuo Takagi, Yuji Mihara
Abstract For various densities of gas jets including very light hydrogen and relatively heavy ones, the penetration length and diffusion process of a single high-speed gas fuel jet injected into air are computed by performing a large eddy simulation (LES) with fewer arbitrary constants applied for the unsteady three-dimensional compressible Navier-Stokes equation. In contrast, traditional ensemble models such as the Reynolds-averaged Navier-Stokes (RANS) equation have several arbitrary constants for fitting purposes. The cubic-interpolated pseudo-particle (CIP) method is employed for discretizing the nonlinear terms. Computations of single-component nitrogen and hydrogen jets were done under initial conditions of a fuel tank pressure of gas fuel = 10 MPa and back pressure of air = 3.5 MPa, i.e., the pressure level inside the combustion chamber after piston compression in the engine.
2017-03-28
Journal Article
2017-01-0269
Doohyun Kim, Jason Martz, Angela Violi
Abstract The ignition delay time for direct injection compression ignition engines is determined by complex physical and chemical phenomena that prepare the injected liquid fuel for gas phase ignition. In this work, Computational Fluid Dynamics (CFD) simulations of a reacting spray within a constant volume spray chamber are conducted to investigate the relative importance of liquid fuel physical properties and oxidation chemistry on the ignition delay time. The simulations use multi-component surrogates that emulate the physical and chemical properties of petroleum-derived (Jet-A) and natural-gas-derived (S-8) jet fuels. Results from numerical experiments isolating the fuel physical property and chemistry effects show that fuel chemistry is significantly more important to ignition delay than fuel physical properties under the conditions studied.
2017-03-28
Technical Paper
2017-01-0640
Robert Wade, Steven Murphy, Paul Cross, Craig Hansen
Abstract The Variable Displacement Supercharger (VDS) is a twin helical screw style compressor that has a feature to change its displacement and its compression ratio actively during vehicle operation. This device can reduce the parasitic losses associated with supercharging and improve the relative fuel economy of a supercharged engine. Supercharging is a boosting choice with several advantages over turbocharging. There is fast pressure delivery to the engine intake manifold for fast engine torque response providing the fun to drive feel. The performance delivered by a supercharger can enable engine fuel economy actions to include engine downsizing and downspeeding. The cost and difficulty of engineering hot exhaust components is eliminated when using only an air side compressor. Faster catalyst warm up can be achieved when not warming the turbine housing of a turbocharger.
2017-03-28
Technical Paper
2017-01-0582
Naoki Kurimoto, Naoki Watanabe, Shinya Hoshi, Satoru Sasaki, Masashi Matsumoto
Abstract A methodology for simulating effect of international variations in fuel compositions on spray combustion is proposed. The methodology is validated with spray combustion experiments with real fuels from three different countries. The compositions of those fuels were analyzed through GC×GC and H-NMR. It was found that ignition delay times, flame region and flame luminosity were significantly affected by the compositional variations. For the simulation, an evaporation surrogate consisting of twenty two species, covering basic molecular types and a wide range of carbon numbers, is developed. Each species in the evaporation surrogate is then virtually converted to a reaction surrogate consisting of n-hexadecane, methylcyclohexane and 1,2,4-trimethyl benzene so that combustion reactions can be calculated with a published kinetic model. The virtual species conversion (VSC) is made so as to take over combustion-related properties of each species of evaporation surrogates.
2017-03-28
Technical Paper
2017-01-0664
Mohd Asif, Karl Giles, Andrew Lewis, Sam Akehurst, Niall Turner
Abstract The causes of engine knock are well understood but it is important to be able to relate these causes to the effects of controllable engine parameters. This study attempts to quantify the effects of a portion of the available engine parameters on the knock behavior of a 60% downsized, DISI engine running at approximately 23 bar BMEP. The engines response to three levels of coolant flow rate, coolant temperature and exhaust back pressure were investigated independently. Within the tested ranges, very little change in the knock limited spark advance (KLSA) was observed. The effects of valve timing on scavenge flow and blow through (the flow of fresh air straight into the exhaust system during the valve overlap period) were investigated at two conditions; at fixed inlet/exhaust manifold pressures, and at fixed engine torque. For both conditions, a matrix of 8 intake/exhaust cam combinations was tested, resulting in a wide range of valve overlap conditions (from 37 to -53°CA).
2017-03-28
Technical Paper
2017-01-1232
Tsubasa Yamazakii, Hidekazu Uchiyama, Kazuaki Nakazawa, Tsubasa Isomura, Hisashi Ogata
Abstract Solar car races are held worldwide, aiming to promote vehicles that help reduce environmental loads on the roads. In order to gain superiority in solar car racing, it is essential to develop a high efficiency brushless direct drive motor that optimizes the energy use to the fullest and allows high speed driving when needed. To achieve these goals, two development approaches of solar car motors are proposed: the high efficiency motor which improves electrical characteristics and significantly reduces energy loss; and the variable field magnet motor that offers instant speed boost for a temporary period of time for overtaking opponents. We have developed a high efficiency motor through the application of an amorphous core and laminated magnets. Instead of the standard method of the W-EDM (Wire-Electric Discharge Machining) for amorphous cores, we utilized water jet cutting, through which we succeeded in achieving insulation between laminated cores.
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
2017-01-0811
John Williams, Heather D. Hamje, David J. Rickeard, Andreas Kolbeck, Kalle Lehto, Elena Rebesco, Walter Mirabella, Carole A. Bontoft, Maria Dolores Cardenas
Abstract Research Octane Number (RON) and Motor Octane Number (MON) are used to describe gasoline combustion which describe antiknock performance under different conditions. Recent literature suggests that MON is less important than RON in modern cars and a relaxation in the MON specification could improve vehicle performance. At the same time, for the same octane number change, increasing RON appears to provide more benefit to engine power and acceleration than reducing MON. Some workers have advocated the use of an octane index (OI) which incorporates both parameters instead of either RON or MON to give an indication of gasoline knock resistance. Previous Concawe work investigated the effect of RON and MON on the power and acceleration performance of two Euro 4 gasoline passenger cars during an especially-designed acceleration test cycle.
2017-03-28
Technical Paper
2017-01-0810
Jan-Hendrik Redmann, Maik Beutler, Jennifer Kensler, Martin Luebbers, Roger Cracknell
Abstract In light of increasingly stringent CO2 emission targets, Original Equipment Manufacturers (OEM) have been driven to develop engines which deliver improved combustion efficiency and reduce energy losses. In spark ignition engines one strategy which can be used to reach this goal is the full utilization of fuel octane number. Octane number is the fuel´s knock resistance and is characterized as research octane number (RON) and motor octane number (MON). Engine knock is caused by the undesired self-ignition of the fuel air mixture ahead of the flame front initiated by the spark. It leads to pressure fluctuations that can severely damage the engine. Modern vehicles utilize different strategies to avoid knock. One extreme strategy assumes a weak fuel quality and, to protect the engine, retards the spark timing at the expense of combustion efficiency. The other extreme carefully detects knock in every engine cycle and retards the spark timing only when knock is detected.
2017-03-28
Journal Article
2017-01-1650
Jian Yang, Christian Poellabauer, Pramita Mitra
Abstract Bluetooth Low Energy (BLE) is an energy-efficient radio communication technology that is rapidly gaining popularity for various Internet of Things (IoT) applications. While BLE was not designed specifically with vehicular communications in mind, its simple and quick connection establishment mechanisms make BLE a potential inter-vehicle communication technology, either replacing or complementing other vehicle-to-vehicle (V2V) technologies (such as the yet to be deployed DSRC). In this paper we propose a framework for V2V communication using BLE and evaluate its performance under various configurations. BLE uses two major methods for data transmission: (1) undirected advertisements and scanning (unconnected mode) and (2) using the central and peripheral modes of the Generic Attribute Profile (GATT) connection (connected mode).
2017-03-28
Journal Article
2017-01-1691
Aseim Elfrgani, C. J. Reddy
Abstract A low profile high directivity antenna is designed to operate at 5.9 GHz for Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications to ensure connectivity in different propagation channels. Patch antennas are still an ongoing topic of interest due to their advantages: low profile, low cost, and ease of fabrication. One disadvantage of the patch antenna is low directivity which results in low range performance. In this paper, we introduce an efficient and novel way to improve the directivity of patch antenna using topology optimization and design of experiments (DoE). Numerical simulations are done using Method of Moments (MoM) technique in the commercially available tool, FEKO. We use global response surface method (GRSM) for double objectives topology optimization. Numerical results show a promising use of topology optimization and DoE techniques for the systematic design of high directivity of low profile single element patch antennas.
2017-03-28
Journal Article
2017-01-1563
Abhijeet Behera, Murugan Sivalingam
Abstract Two and three wheeler vehicles are largely used in many developing and under developing countries because of their lower cost, better fuel economy and easy handling. Although, the construction of them is simpler than the four wheeler vehicle, they pose some problems related to instability. Wobbling is the main cause of instabilities in two wheeler and three wheeler vehicles. In this study, a mathematical model was proposed and developed to determine wobble instability of a two wheeler. Nonlinear equations were formulated by using kinematics and the D’Alembert’s principle with the help of multi body formalism. The non-linear equations found in the study were linearized with respect to rectilinear and upright motion, considering no rolling. It led to formation of matrix. The real part of the Eigen value of the matrix was found to be negative, implication of whose was an asymptotic stable motion.
2017-03-28
Journal Article
2017-01-0073
Andreas Barthels, Christian Ress, Martin Wiecker, Manfred Müller
Abstract Vehicle to Vehicle Communication use case performance heavily relies on market penetration rate. The more vehicles support a use case, the better the customer experience. Enabling these use cases with acceptable quality on vehicles without built-in navigation systems, elaborate map matching and highly accurate sensors is challenging. This paper introduces a simulation framework to assess system performance in dependency of vehicle positioning accuracy for matching approach path traces in Decentralized Environmental Notification Messages (DENMs) in absence of navigation systems supporting map matching. DENMs are used for distributing information about hazards on the road network. A vehicle without navigation system and street map can only match its position trajectory with the trajectory carried in the DENM.
2017-03-28
Journal Article
2017-01-0077
Scott E. Bogard, Shan Bao, David LeBlanc, Jun Li, Shaobo Qiu, Bin Liu
Abstract This paper provides an analysis of how communication performance between vehicles using Dedicated Short-range Communication (DSRC) devices varies by antenna mounting, vehicle relative positions and orientations, and between receiving devices. DSRC is a wireless technology developed especially for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. A frequency band near 5.9 GHz has been set aside in the US and other countries for exploring safety and other uses for road vehicles. DSRC devices installed onboard vehicles broadcast their location using global navigation space systems (GNSS), speed, heading, and other information. This can be used to study communication performance in many scenarios including: car-following situations, rear-end crash avoidance, oncoming traffic situations, left turn advisory, head-on crash avoidance and do-not-pass warnings.
2017-03-28
Journal Article
2017-01-0687
Patrick Haenel, Henning Kleeberg, Rob de Bruijn, Dean Tomazic
Abstract Modern combustion engines must meet increasingly higher requirements concerning emission standards, fuel economy, performance characteristics and comfort. Especially fuel consumption and the related CO2 emissions were moved into public focus within the last years. One possibility to meet those requirements is downsizing. Engine downsizing is intended to achieve a reduction of fuel consumption through measures that allow reducing displacement while simultaneously keeping or increasing power and torque output. However, to reach that goal, downsized engines need high brake mean effective pressure levels which are well in excess of 20bar. When targeting these high output levels at low engine speeds, undesired combustion events with high cylinder peak pressures can occur that can severely damage the engine. These phenomena, typically called low speed pre-ignition (LSPI), set currently an undesired limit to downsizing.
2017-03-28
Technical Paper
2017-01-0720
Omar Ramadan, Luc Menard, David Gardiner, Aaron Wilcox, Gary Webster
Abstract This paper is a continuation of work previously discussed in SAE 2014-01-0179 [1] and SAE 2015-01-0805 [2], which was intended to improve the capability and precision of the Ignition Quality Tester (IQT™) and associated ASTM D6890 [3]/CEN EN 15195 [4]/EI IP 498 [5] Test Methods. The results presented in those two papers indicated how the new generation of IQT™ with the TALM Precision Package upgrade can markedly improve the precision of the ASTM D6890, CEN EN 15195 and EI IP 498 Derived Cetane Number (DCN) test methods. This paper will evaluate the performance of the upgraded instruments over the past 21 months of their participation in ASTM’s National Fuel Exchange Group (NEG) diesel fuel exchange program.
2017-03-28
Technical Paper
2017-01-0690
Maziar Khosravi, Helmut Ruhland, Thomas Lorenz, Carsten Weber
Abstract The performance of boosted gasoline engines is limited at high loads by knock, stochastic Low Speed Pre-Ignition, and Megaknock. An investigation has been carried out on the occurrence of abnormal combustion and megaknock in a 1.6 L GTDI engine with the aim to determine the causes of such phenomena. A classification of abnormal combustion events and causes is presented in order to facilitate a consistent terminology. The experiments specifically focus on the effects of exhaust residual gas on occurrence of megaknock in multi-cylinder engines. The results showed that while a misfire will not lead to megaknock, a very late combustion in one cycle, in one cylinder may lead to megaknock in the following cycle in the same or adjacent cylinder. Additionally, a recently developed multi-zone model was used to analyze the role of residual gas on auto-ignition.
2017-03-28
Technical Paper
2017-01-0766
Gary D. Neely, Radu Florea, Jason Miwa, Zainal Abidin
Abstract The CO2 advantage coupled with the low NOX and PM potential of natural gas (NG) makes it well-suited for meeting future greenhouse gas (GHG) and NOX regulations for on-road medium and heavy-duty engines. However, because NG is mostly methane, reduced combustion efficiency associated with traditional NG fueling strategies can result in significant levels of methane emissions which offset the CO2 advantage due to reduced efficiency and the high global warming potential of methane. To address this issue, the unique co-direct injection capability of the Westport HPDI fuel system was leveraged to obtain a partially-premixed fuel charge by injecting NG during the compression stroke followed by diesel injection for ignition timing control. This combustion strategy, referred to as DI2, was found to improve thermal and combustion efficiencies over fumigated dual-fuel combustion modes.
2017-03-28
Technical Paper
2017-01-0755
Karthik Nithyanandan, Yongli Gao, Han Wu, Chia-Fon Lee, Fushui Liu, Junhao Yan
Abstract Dual-fuel combustion combining a premixed charge of compressed natural gas (CNG) and a pilot injection of diesel fuel offer the potential to reduce diesel fuel consumption and drastically reduce soot emissions. In this study, dual-fuel combustion using methane ignited with a pilot injection of No. 2 diesel fuel, was studied in a single cylinder diesel engine with optical access. Experiments were performed at a CNG substitution rate of 70% CNG (based on energy) over a wide range of equivalence ratios of the premixed charge, as well as different diesel injection strategies (single and double injection). A color high-speed camera was used in order to identify and distinguish between lean-premixed methane combustion and diffusion combustion in dual-fuel combustion. The effect of multiple diesel injections is also investigated optically as a means to enhance flame propagation towards the center of the combustion chamber.
2017-03-28
Journal Article
2017-01-0033
Scott Stevens, Jeffrey Bellone, Philip Azeredo, Marisol Medri
Abstract This study is aimed at supporting left-turn assist (LTA) applications, which provide warnings to drivers making a left turn across the path of oncoming traffic (LTAP/OD scenarios). The primary goal was to provide much-needed information on typical or “baseline” driving in LTAP/OD scenarios that can be used to refine alert criteria to reduce false and nuisance alerts. A secondary goal was to provide performance data useful for informing practical test procedures, e.g., setting turning speed when evaluating LTA applications on a test track. To accomplish this, LTAP/OD events were identified in the databases of two large-scale naturalistic driving studies. For these events, we estimated the size of the gaps in oncoming traffic into which drivers chose to turn, what factors (environmental, demographic, etc.) affected the choice to turn into a gap of a given size, and the speed profiles throughout each turn.
2017-03-28
Technical Paper
2017-01-1187
Tatsuya Sugawara, Takuma Kanazawa, Naoki Imai, Yu Tachibana
Abstract This paper describes the motorized turbo compressor, which is a key technology for reducing the size of the fuel cell system for the Clarity Fuel Cell. The oxygen needed for fuel cell power generation is sent into the fuel cell by compressing the air from the atmosphere by a compressor. The conventionally used Lysholm compressor needed numerous sound absorbers, such as silencers and covers, to help achieve quietness when driving. Therefore, changing to a turbo compressor enhanced quietness and helped to eliminate or reduce the size of these auxiliary sound absorbers. Furthermore, a two-stage supercharging structure was used and the air pressure supplied to the fuel cell was increased to 1.7 times the previous air pressure. This increased the fuel cell power, which enabled to reduce the number of cells needed, and reduced the needed humidification amount which enabled to reduce the size of the humidifier. These enhancements helped to reduce the system size.
2017-03-28
Technical Paper
2017-01-0778
Vishnu Vijayakumar, P. Sakthivel, Bhuvenesh Tyagi, Amardeep Singh, Reji Mathai, Shyam Singh, Ajay Kumar Sehgal
Abstract In the light of major research work carried out on the detrimental health impacts of ultrafine particles (<50 nm), Euro VI emission standards incorporate a limit on particle number, of which ultrafine particles is the dominant contributor. As Compressed Natural Gas (CNG) is a cheaper and cleaner fuel when compared to diesel, there has been a steady increase in the number of CNG vehicles on road especially in the heavy duty segment. Off late, there has been much focus on the nature of particle emissions emanating from CNG engines as these particles mainly fall under the ultrafine particle size range. The combustion of lubricant is considered to be the dominant source of particle emissions from CNG engines. Particle emission due to lubricant is affected by the oil transport mechanisms into the combustion chamber which in turn vary with engine operating conditions as well as with the physico chemical properties of the lubricant.
2017-03-28
Technical Paper
2017-01-0567
Andrea Twellmeyer, Fabian Kopple, Bernhard Weigand
Abstract Compressed Natural Gas (CNG) is a promising alternative fuel for internal combustion engines as its combustion is fuel-efficient and lean in carbon dioxide compared to gasoline. The high octane number of methane gives rise to significant increase of the thermodynamic efficiency due to higher possible compression ratios. In order to use this potential, new stratified mixture formation concepts for CNG are investigated by means of numerical fluid simulations. For decades RANS methods have been the industry standard to model three-dimensional flows. Indeed, there are well-known deficiencies of the widely used eddy viscosity turbulence models based on the applied Boussinesq hypothesis. Reynolds stress turbulence models as well as scale resolving simulation approaches can be appealing alternative choices since they offer higher accuracy. However, due to their large computing effort, they are still mostly impractical for the daily use in industrial product development processes.
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
Technical Paper
2017-01-0885
Bhuvenesh Tyagi, Vishnu Vijayakumar, Shyam Singh, Ajay Kumar Sehgal, R Suresh
Abstract Majority of light and heavy duty commercial vehicles on road in India use API-CF grade lubricants. Soot accumulation in lubricating oil can result in engine wear and lubricant’s viscosity increase thereby affecting its pumping ability and drain interval. Due to faster lubricant degradation and with emergence of newer engine technologies, there is increasing demand of improving performance of lubricants particularly with respect to soot dispersancy. This paper describes the various engine hardware modifications and optimizations carried out on a commercial BS II, 4-cylinder turbocharged diesel engine in order to develop a flexible engine test procedure for evaluating the lubricant’s dispersancy/anti wear characteristics up to 6% soot levels.
2017-03-28
Technical Paper
2017-01-0887
Dairene Uy, George Pranis, Anthony Morelli, Arup Gangopadhyay, Alexander Michlberger, Nicholas Secue, Mike Kinzel, Tina Adams, Kevin Streck, Michael Lance, Andrew Wereszczak
Abstract Deposit formation within turbocharger compressor housings can lead to compressor efficiency degradation. This loss of turbo efficiency may degrade fuel economy and increase CO2 and NOx emissions. To understand the role that engine oil composition and formulation play in deposit formation, five different lubricants were run in a fired engine test while monitoring turbocharger compressor efficiency over time. Base stock group, additive package, and viscosity modifier treat rate were varied in the lubricants tested. After each test was completed the turbocharger compressor cover and back plate deposits were characterized. A laboratory oil mist coking rig has also been constructed, which generated deposits having the same characteristics as those from the engine tests. By analyzing results from both lab and engine tests, correlations between deposit characteristics and their effect on compressor efficiency were observed.
Viewing 121 to 150 of 16434