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Viewing 1 to 30 of 297
2017-03-28
Technical Paper
2017-01-0688
Derek Splitter, Brian Kaul, James Szybist, Gurneesh Jatana
This work explores the dependence of fuel ignition delay on stochastic pre-ignition (SPI). Findings are based on bulk gas thermodynamic state, where the effects of pre-spark heat release (PSHR) are correlated to SPI tendency and magnitude. Specifically, residual gas and low temperature chemistry effects and observations are explored, which are found to be indicative of bulk gas conditions required for strong SPI events. Events analyzed range from non-knocking SPI to full detonation SPI events in excess of 325 bar peak cylinder pressure. The work illustrates that singular SPI event count and magnitude are found to be proportional to PSHR of the bulk gas mixture and residual gas fraction. Cycle-to-cycle variability in trapped residual mass and temperature are found to impose variability in singular SPI event count and magnitude.
2017-03-28
Technical Paper
2017-01-0681
Gurneesh S. Jatana, Brian C. Kaul
Use of dilution with exhaust gas recirculation (EGR) in spark ignition (SI) engines offers substantial efficiency gains, especially, when boosting and downsizing is employed. However, the onset of instabilities in engine operation, due to misfires and partial burns, limits the dilution levels. Control models can be employed to improve engine stability during high dilution operation, and spark and fueling are one of many control parameters available for cycle-to-cycle control implementation. This paper aims to understand the sensitivity of the combustion process to changes in fueling at various dilution levels achieved with both excess air (lean operation) and EGR. Sinusoidal perturbation was introduced into the injected fuel quantity and the sensitivity to this perturbation was characterized using a fast Fourier transform (FFT) analysis of the cycle cumulative heat release data.
2017-03-28
Technical Paper
2017-01-0747
John Storey, Samuel Lewis, Melanie Moses-DeBusk, Raynella Connatser, Jong Lee, Tom Tzanetakis, Kukwon Cho, Matthew Lorey, Mark Sellnau
Low temperature combustion (LTC) engine technologies are being investigated for high efficiency and low emissions. However, such engine technologies often produce high hydrocarbon (HC) and carbon monoxide (CO) emissions, and their operating range is limited primarily by the fuel properties. High reactivity gasoline fuels have been reported to help achieve partially premixed compression ignition (PPCI) at light-to-medium load conditions. In this study, two different fuels, a US market gasoline containing 10% ethanol (RON91 E10) and a high reactivity gasoline (RON80), were compared on a Delphi’s second generation Gasoline Direct-Injection Compression Ignition (GDCI) multi-cylinder engine. The engine was evaluated at three operating points ranging from a light load condition (800 rpm/2 bar IMEP) to a medium load condition (1500 rpm/6 bar IMEP and 2000 rpm/10 bar IMEP). The engine was equipped with two oxidation catalysts with exhaust gas recirculation (EGR) inlet located in-between.
2017-03-28
Technical Paper
2017-01-0897
Gregory Pannone, John Thomas, Michael Reale, Brian Betz
The three foundational elements that determine mobile source energy use and tailpipe carbon dioxide (CO2) emissions are the tractive energy requirements of the vehicle, the on-cycle energy conversion efficiency of the propulsion system, and the energy source. Tractive energy requirements are determined by the vehicle's mass, aerodynamic drag, tire rolling resistance, and parasitic drag. The on-cycle energy conversion of the propulsion system is dictated by the tractive efficiency, non-tractive energy use, kinetic energy recovery, and parasitic losses. The energy source determines the mobile source CO2 emissions. Current tractive energy requirements and overall energy conversion efficiency are readily available from the decomposition of available test data. For future applications, plausible levels of mass reduction, aerodynamic drag improvements, and tire rolling resistance can be transposed into the tractive energy domain.
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
Deposit formation on the turbocharger compressor housing can lead to compressor efficiency degradation, which leads to loss of fuel economy and increase in CO2 and NOx emissions. To understand the role that engine oil composition and formulation play in these deposits which arise from oil aerosols and particulates from the closed crankcase ventilation, fIve different lubricants were run in a fired engine test to evaluate turbocharger compressor efficiency. Basestock group, additive package, and viscosity modifier treat rate were varied in the lubricants tested. After each test was completed the turbocharger compressor cover and backplate 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.
2017-03-28
Technical Paper
2017-01-0183
Mingyu Wang, Timothy Craig, Edward Wolfe, Tim LaClair, Zhiming Gao, Michael Levin, Danrich Demitroff, Furqan Shaikh
Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by electrical energy from the traction battery. In very cold climatic conditions, the driving range of an EV can be reduced by 50% or more. To minimize this EV range penalty, a novel thermal energy storage system has been designed to provide cabin heat in EVs and Plug-in Hybrid Electric Vehicles (PHEVs) using the stored latent heat from an advanced phase change material (PCM). This system is known as the Electrical PCM-based Thermal Heating System (ePATHS). When the EV is connected to the electric grid to charge its traction battery, the ePATHS system is also “charged” by melting the PCM. The stored thermal energy is subsequently deployed for cabin heating during driving.
2017-03-28
Technical Paper
2017-01-1605
Paul Chambon, Dean Deter, David Smith, Grant Bauman
Electric machines, whether in battery electric vehicles (BEVs) or various other applications, are an important part of modern transportation strategies. Traditionally, mathematical models in based on steady-state mapping of electric machines have been used to evaluate the behavior of the machines under transient conditions. Hardware-in-the-Loop (HIL) testing seeks to provide a more accurate representation of a component’s behavior under transient load conditions that are more representative of real world conditions it will operate under, without resourcing to full vehicle installation. Oak Ridge National Laboratory (ORNL) developed such a HIL test platform capable of subjecting electric machines to both conventional steady-state test procedures as well as transient experiments such as vehicle drive cycles.
2017-03-28
Technical Paper
2017-01-0802
Michael D. Kass, Brian West
The compatibility of notable infrastructure elastomers with bio-blendstock derived single molecule fuel candidates and their blends with a gasoline representative were examined using solubility analysis. The elastomer materials include fluorocarbon, acrylonitrile butadiene rubber (NBR), styrene butadiene (SBR), neoprene, polyurethane and silicone. These materials have been rigorously studied with other fuel types, and their volume change results were found to correspond well with their predicted solubility levels. The fuel candidates include alcohols, alkanes, alkenes, aromatics, esters, ethers and ketones. Dodecane was used as a baseline gasoline (or E0) representative along with a blend of dodecane and 10% ethanol (E10). A Hansen solubility analysis was performed for each elastomer with each fuel candidate and a blend of each fuel candidate with dodecane.
2017-03-28
Technical Paper
2017-01-0824
Daniel J. Duke, Charles E.A. Finney, Alan Kastengren, Katarzyna Matusik, Nicolas Sovis, Louis Santodonato, Hassina Bilheux, David Schmidt, Christopher Powell, Todd Toops
Given the importance of the fuel-injection process on the combustion and emissions performance of gasoline direct injected engines, there has been significant recent interest in understanding the fluid dynamics within the injector, particularly around the needle and through the nozzles. The pressure losses and transients which occur in the flow passages above the needle are also of interest. Simulations of these injectors typically use the nominal design geometry, which does not always match the production geometry. Computed tomography (CT) using x-ray and neutron sources can be used to obtain the real geometry from production injectors, but there are trade-offs in using these techniques. X-ray CT provides high resolution, but cannot penetrate through the thicker parts of the injector. Neutron CT has excellent penetrating power but lower resolution.
2017-03-28
Technical Paper
2017-01-0988
Michael Cunningham, Mi-Young Kim, Venkata Lakkireddy, William Partridge
Measuring axial exhaust species concentration distributions within a wall-flow aftertreatment device provides unique and significant insights regarding the performance of complex devices like the SCR-on-filter. In this particular study, a less complex aftertreatment configuration which includes a DOC followed by two uncoated partial flow filters (PFF) was used to demonstrate the potential and challenges. The PFF design in this study was a particulate filter with both through and plugged (or wall-flow) channels. A SpaciMS instrument was used to measure the axial NO2 profiles within adjacent through and plugged channels of each filter element during an extended passive regeneration event using a full-scale engine and catalyst system. By estimating the mass flow through the plugged and through channels, the axial soot load profile history could be assessed.
2017-03-28
Technical Paper
2017-01-0772
ShyamSundar Pasunurthi, Ravichandra Jupudi, Sameera Wijeyakulasuriya, Sreenivasa Rao Gubba, Hong Im, mohammed jaasim Mubarak ali, Roy Primus, Adam Klingbeil, Charles Finney
The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP) is captured from many consecutive combustion cycles for each test condition. However, obtaining 3D spatial distribution of all the relevant quantities from such experiments is a challenging task. Computational Fluid Dynamics (CFD) simulations of engine flow and combustion can be used effectively to visualize such 3D spatial distributions. A dual fuel engine is considered in the current study, with port injected natural gas (NG) and direct injected diesel pilot for ignition. Multiple 3D CFD simulations are performed in series like in the experiments to investigate the potential of high fidelity RANS simulations coupled with detailed chemistry, to accurately predict the CCV. Measured valve lift profiles are used to specify the valve movements in the simulations.
2017-03-28
Technical Paper
2017-01-0950
Alexander Sappok, Paul Ragaller, Andrew Herman, Leslie Bromberg, Vitaly Prikhodko, James Parks, John Storey
The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications.
2017-03-28
Technical Paper
2017-01-1000
Jong Lee, Yu Zhang, Tom Tzanetakis, Michael Traver, Melanie Moses-DeBusk, John Storey, William Partridge, Michael Lance
With higher volatility and longer ignition delay characteristics than typical diesel fuel, low cetane naphtha fuel has been shown to promote partially premixed combustion and produce lower soot for improved fuel economy. In this study, emission performance of low cetane, low octane naphtha (CN 35, RON 60) as a drop-in fuel was examined on a MY13 Cummins ISX15 6-cylinder heavy-duty on-highway truck engine and aftertreatment system. Using the production hardware and development calibrations, both the engine-out and tailpipe emissions of naphtha and ultra-low sulfur diesel (ULSD) fuels were examined during the EPA’s heavy-duty emission testing cycles. Without any modification to the calibrations, the tailpipe emissions were comparable when using naphtha or ULSD on the heavy duty Federal Test Procedure (FTP) and ramped modal cycle (RMC) test cycles.
2016-10-17
Journal Article
2016-01-2322
Michael Lance, Andrew Wereszczak, Todd J. Toops, Richard Ancimer, Hongmei An, Junhui Li, Leigh Rogoski, Petr Sindler, Aaron Williams, Adam Ragatz, Robert L. McCormick
Abstract For renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent to exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement.
2016-08-02
Article
3D printing a car is impressive enough; building an excavator, layer by layer, is downright unimaginable. Researchers at Oak Ridge National Laboratory have not only imagined it, they plan to execute it next spring at ConExpo/Con-Agg in Las Vegas with a live demonstration.
2016-06-20
Article
In the additive manufacturing world, the costs of components are dropping, the technology is becoming more reliable and parts are fabricated faster. This is allowing industries such as automotive to adopt additive technologies, says Oak Ridge Lab's Ryan Dehoff.
2016-06-15
Book
John Turner
Modeling and simulation of batteries, in conjunction with theory and experiment, are important research tools that offer opportunities for advancement of technologies that are critical to electric motors. The development of data from the application of these tools can provide the basis for managerial and technical decision-making. Together, these will continue to transform batteries for electric vehicles.
2016-06-11
Article
Novel oxidation ovens could triple production-line throughput while slashing energy use.
2016-04-05
Technical Paper
2016-01-0328
Scott Curran, Paul Chambon, Randall Lind, Lonnie Love, Robert Wagner, Steven Whitted, David Smith, Brian Post, Ronald Graves, Craig Blue, Johney Green, Martin Keller
Abstract Rapid vehicle powertrain development has become a technological breakthrough for the design and implementation of vehicles that meet and exceed the fuel efficiency, cost, and performance targets expected by today’s consumer. Recently, advances in large scale additive manufacturing have provided the means to bridge hardware-in-the-loop with preproduction mule chassis testing. This paper details a case study from Oak Ridge National Laboratory bridging the powertrain-in-the-loop development process with vehicle systems implementation using big area additive manufacturing (BAAM). For this case study, the use of a component-in-the-loop laboratory with math-based models is detailed for the design of a battery electric powertrain to be implemented in a printed prototype mule. The ability for BAAM to accelerate the mule development process via the concept of computer-aided design to part is explored.
2016-04-05
Technical Paper
2016-01-0691
Gurneesh S. Jatana, Brian C. Kaul, Robert Wagner
Abstract Spark-ignition (SI) engines can derive substantial efficiency gains from operation at high dilution levels, but sufficiently high-dilution operation increases the occurrence of misfires and partial burns, which induce higher levels of cyclic-variability in engine operation. This variability has been shown to have both stochastic and deterministic components, with residual fraction impacts on charge composition being the major source of the deterministic component through its non-linear effect on ignition and flame propagation characteristics. This deterministic coupling between cycles offers potential for next-cycle control approaches to allow operation near the edge of stability. This paper aims to understand the effect of spark strategies, specifically the use of a second spark (restrike) after the main spark, on the deterministic coupling between engine cycles by operating at high dilution levels using both excess air (i.e. lean combustion) and EGR.
2016-04-05
Technical Paper
2016-01-0248
Mingyu Wang, Edward Wolfe, Timothy Craig, Tim J. Laclair, Omar Abdelaziz, Zhiming Gao
Abstract Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating.
2016-04-05
Technical Paper
2016-01-0798
Ravichandra S. Jupudi, Charles E.A. Finney, Roy Primus, Sameera Wijeyakulasuriya, Adam E. Klingbeil, Bhaskar Tamma, Miroslav K. Stoyanov
Abstract Interest in operational cost reduction is driving engine manufacturers to consider low-cost fuel substitution in heavy-duty diesel engines. These dual-fuel (DF) engines could be operated either in diesel-only mode or operated with premixed natural gas (NG) ignited by a pilot flame of compression-ignited direct-injected diesel fuel. Under certain conditions, dual-fuel operation can result in increased cycle-to-cycle variability (CCV) during combustion. CFD can greatly help in understanding and identifying critical parameters influencing CCV. Innovative modelling techniques and large computing resources are needed to investigate the factors affecting CCV in dual-fuel engines. This paper discusses the use of the High Performance Computing resource Titan, at Oak Ridge National Laboratory, to investigate CCV of a dual-fuel engine.
2016-04-05
Technical Paper
2016-01-0937
James E. Parks, John M. E. Storey, Vitaly Y. Prikhodko, Melanie M. Debusk, Samuel A. Lewis
Abstract New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDI PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal.
2016-04-05
Technical Paper
2016-01-0918
Alexander Sappok, Paul Ragaller, Leslie Bromberg, Vitaly Prikhodko, John Storey, James Parks
Abstract Radio frequency (RF)-based sensors provide a direct measure of the particulate filter loading state. In contrast to particulate matter (PM) sensors, which monitor the concentration of PM in the exhaust gas stream for on-board diagnostics purposes, RF sensors have historically been applied to monitor and control the particulate filter regeneration process. This work developed an RF-based particulate filter control system utilizing both conventional and fast response RF sensors, and evaluated the feasibility of applying fast-response RF sensors to provide a real-time measurement of engine-out PM emissions. Testing with a light-duty diesel engine equipped with fast response RF sensors investigated the potential to utilize the particulate filter itself as an engine-out soot sensor.
2016-04-05
Journal Article
2016-01-0835
Michael D. Kass, Charles Daw
Abstract The compatibility of notable infrastructure elastomers and plastics with DME and its blends with diesel fuel were examined using solubility analysis. The elastomer materials were fluorocarbon, acrylonitrile butadiene rubber (NBR), styrene butadiene (SBR), neoprene, polyurethane and silicone. Plastic materials included polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyoxymethylene (POM), polybutylene terephthalate (PBT), polypropylene (PP), high density polyethylene (HDPE), along with several nylon grades and thermosetting resins. These materials have been rigorously studied with other fuel types, and their volume change results were found to correspond well with their predicted solubility levels. A Hansen solubility analysis was performed for each material with DME, diesel, and blends of both fuel components.
2016-04-05
Journal Article
2016-01-0836
C. Scott Sluder, James P. Szybist, Robert L. McCormick, Matthew A. Ratcliff, Bradley T. Zigler
Abstract The latent heat-of-vaporization (HoV) of blends of biofuel and hydrocarbon components into gasolines has recently experienced expanded interest because of the potential for increased HoV to increase fuel knock resistance in direct-injection (DI) engines. Several studies have been conducted, with some studies identifying an additional anti-knock benefit from HoV and others failing to arrive at the same conclusion. Consideration of these studies holistically shows that they can be grouped according to the level of fuel octane sensitivity variation within their fuel matrices. When comparing fuels of different octane sensitivity significant additional anti-knock benefits associated with HoV are sometimes observed. Studies that fix the octane sensitivity find that HoV does not produce additional anti-knock benefit. New studies were performed at ORNL and NREL to further investigate the relationship between HoV and octane sensitivity.
2016-04-05
Journal Article
2016-01-0897
Dairene Uy, John Storey, C. Scott Sluder, Teresa Barone, Sam Lewis, Mark Jagner
Abstract The recirculation of gases from the crankcase and valvetrain can potentially lead to the entrainment of lubricant in the form of aerosols or mists. As boost pressures increase, the blow-by flow through both the crankcase and the valve cover increases. The resulting lubricant can then become part of the intake charge, potentially leading to fouling of intake components such as the intercooler and the turbocharger. The entrained aerosol which can contain the lubricant and soot may or may not have the same composition as the bulk lubricant. The complex aerodynamic processes that lead to entrainment can strip out heavy components or volatilize light components. Similarly, the physical size and numbers of aerosol particles can be dependent upon the lubricant formulation and engine speed and load. For instance, high rpm and load may increase not only the flow of gases but the amount of lubricant aerosol.
2016-04-05
Journal Article
2016-01-0909
John Thomas
Abstract A major driving force for change in light-duty vehicle design and technology is the National Highway Traffic Safety Administration (NHTSA) and the U.S. Environmental Protection Agency (EPA) joint final rules concerning Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emissions for model years 2017 (MY17) through 2025 (MY25) passenger cars and light trucks. The chief goal of this current study is to compare the already rapid pace of fuel economy improvement and technological change over the previous decade to the required rate of change to meet regulations over the next decade. EPA and NHTSA comparisons of the model year 2005 (MY05) US light-duty vehicle fleet to the model year 2015 (MY15) fleet shows improved fuel economy (FE) of approximately 26% using the same FE estimating method mandated for CAFE regulations. Future predictions by EPA and NHTSA concerning ensemble fleet fuel economy are examined as an indicator of required vehicle rate-of-change.
2016-04-05
Journal Article
2016-01-0639
Brian C. Kaul, Benjamin Lawler, Akram Zahdeh
Abstract Engine acoustics measured by microphones near the engine have been used in controlled laboratory settings for combustion feedback and even combustion phasing control, but the use of these techniques in a vehicle where many other noise sources exist is problematic. In this study, surface-mounted acoustic emissions sensors are embedded in the block of a 2.0L turbocharged GDI engine, and the signal is analyzed to identify useful feedback features. The use of acoustic emissions sensors, which have a very high frequency response and are commonly used for detecting material failures for health monitoring, including detecting gear pitting and ring scuffing on test stands, enables detection of acoustics both within the range of human hearing and in the ultrasonic spectrum. The high-speed acoustic time-domain data are synchronized with the crank-angle-domain combustion data to investigate the acoustic emissions response caused by various engine events.
2016-04-05
Journal Article
2016-01-0715
James P. Szybist, Derek Splitter
Abstract Fuel-specific differences in exhaust gas recirculation (EGR) dilution tolerance are studied in a modern, direct-injection single-cylinder research engine. A total of 6 model fuel blends are examined at a constant research octane number (RON) of 95 using n-heptane, isooctane, toluene, and ethanol. Laminar flame speeds for these mixtures, which are calculated using two different methods (an energy fraction mixing rule and a detailed kinetic simulation), span a range of about 6 cm/s. A nominal load of 350 kPa IMEPg at 2000 rpm is maintained with constant fueling and varying CA50 from 8-20 CAD aTDCf. EGR is increased until a COV of IMEP of 5% is reached. The results illustrate that flame speed affects EGR dilution tolerance; fuels with increased flame speeds have increased EGR tolerance. Specifically, flame speed correlates most closely to the initial flame kernel growth, measured as the time of ignition to 5% mass fraction burned.
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