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Viewing 1 to 30 of 577
2017-03-28
Technical Paper
2017-01-0800
Varun Gauba, Tushar Bera, Jannik Reitz, Gregory Hansen, Peter Lee, Craig Wileman, Edward Nelson
Piston ring and liner wear measurements and analyses were performed in a production 3.6L V6 gasoline engine with radiolabelled engine parts. Three isotopes were generated: one in the engine liner using surface layer activation; one each in the top ring face and top ring side using bulk activation. Real-time wear measurements and subsequent rates of these three surfaces were captured using the radioactive decay of the isotopes into the engine oiling system. In addition, surface roughness and wear profile measurements were carried out using both white light interferometry, and traditional surface profilometry. The results from Phase I provided insights on evolution of wear and wear rates in critical engine components in a gasoline engine. Phase II will extend this work further and focus on evaluating the additive effects on engine wear.
2017-03-28
Technical Paper
2017-01-0580
Zainal Abidin, Kevin Hoag, Nicholas Badain
The promising D-EGR engine results achieved in the test cell, and then in a vehicle demonstration have led to exploration of further possible applications. A study has been conducted to explore the use of D-EGR engines as a lower cost replacement for medium duty diesel engines in trucks and construction equipment. However, medium duty engines have larger displacement, and tend to require high torque at lower engine speeds than their automobile counterparts. Transmission and final drive gearing can be utilized to operate the engine at higher speeds, but this penalizes life-to-overhaul. It is therefore important to ensure that D-EGR combustion system performance can be maintained with a larger cylinder bore, and with high specific output at relatively low engine speeds. Based on application projections studied in the study, an engine having a 107mm bore and 124mm stroke, operating at 2000 rpm at 17 bar Brake Mean Effective Pressure (BMEP) was selected as representative.
2017-03-28
Technical Paper
2017-01-1135
Sen Zhou, Bryan Williams
The transmission spinloss has significant influences on the vehicle fuel economy. Transmission output chain may have 10~15% contribution to it. However, the chain spinloss information is very rare. It is challenge to give a good estimation of the chain spinloss. An experimental study was carried out with several transmission output chains and simulated transmission environment in a testing box. The studies build the bases for the chain spinloss modeling and depicted the influences of the speed, the sprocket sizes, the oil levels, the viscosity, the temperatures and the baffle. The kriging was employed for the parameter sensitivity study. The results indicate that the speed, the sprocket width, the oil height and the viscosity are the top influencers depending upon the speed range.
2017-03-28
Technical Paper
2017-01-0882
Alexander Michlberger, Peter Morgan, Ewan E. Delbridge, Matthew D. Gieselman, Michael Kocsis
Fuel economy is not an absolute attribute, but is highly dependent on the method used to evaluate it. In this work, two test methods are used to evaluate the differences in fuel economy brought about by changes in engine oil viscosity grade and additive chemistry. The two test methods include a chassis dynamometer vehicle test and an engine dynamometer test. The vehicle testing was conducted using the Federal Test Procedure (FTP) testing protocol while the engine dynamometer test uses the proposed Sequence VIE fuel economy improvement 1 (FEI1) testing methodology. In efforts to improve agreement between the two testing methods, the same model engine was used in both test methods, the GM 3.6L V6 (2012 model year Chevrolet Malibu engine). Within the lubricant industry, this choice of engine is reinforced because it has been selected for use in the proposed Sequence VIE fuel economy test. Results indicate that agreement between methods does exist for some oils.
2017-03-28
Technical Paper
2017-01-0647
Bradley Denton, Christopher Chadwell, Raphael Gukelberger, Terrence Alger
The Dedicated EGR (D-EGR®) engine has shown improved efficiency and emissions while minimizing the challenges of traditional cooled EGR. The concept combines the benefits of cooled EGR with additional improvements resulting from in-cylinder fuel reformation. The fuel reformation takes place in the dedicated cylinder, which is also responsible for producing the diluents for the engine (EGR). The D-EGR system does present its own set of challenges. Because only one out of four cylinders is providing all of the dilution and reformate for the engine, there are three “missing” EGR pulses and problems with EGR distribution to all 4 cylinders exist. In testing, distribution problems were realized which led to poor engine operation. To address these spatial and temporal mixing challenges, a distribution mixer was developed and tested which improved cylinder-to-cylinder and cycle-to-cycle variation of EGR rate through improved EGR distribution.
2017-03-28
Technical Paper
2017-01-0957
Ian Smith, Thomas Briggs, Christopher Sharp, Cynthia Webb
Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr; however, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOx emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOx emissions. This paper details the work executed to achieve 0.02 g/bhp-hr NOx emissions over the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled to an advanced catalyst system.
2017-03-28
Technical Paper
2017-01-0648
Dennis Robertson, Christopher Chadwell, Terrence Alger, Jacob Zuehl, Raphael Gukelberger, Bradley Denton, Ian Smith
Dedicated EGR (D-EGR) is a novel EGR strategy that uses in-cylinder reformation to improve fuel economy and reduce emissions. The entire exhaust of a sub-group of power cylinders (dedicated cylinders) is routed directly into the intake. These cylinders can be run fuel-rich, producing H2 and CO (reformate), with the potential to improve combustion stability, knock tolerance, and burn duration. A 2.0 L turbocharged D-EGR engine was packaged into a 2012 Buick Regal and evaluated on drive cycle performance. City and highway fuel consumption were reduced by 13% and 9%, respectively. NOx + NMOG were 31 mg/mile, well below the Tier 2 Bin 5 limit, and just outside the LEV-III limit (30 mg/mile).
2017-03-28
Technical Paper
2017-01-0865
Mark Walls, Michael Joo, Michael Ross
Liquefied petroleum gas (LPG) is commonly known as autogas when used as a fuel for internal combustion engines. Autogas is primarily made up of propane, but can contain small amounts of butane, methane and propylene. Autogas is not a new fuel for internal combustion engines, but as engine technology evolves, the properties of autogas can be utilized to improve engine and vehicle efficiency. With support from the Propane Education & Research Council (PERC), Southwest Research Institute (SwRI) performed testing to quantify efficiency differences with liquid autogas direct injection in a modern downsized and boosted direct-injected engine using the production gasoline fuel injection hardware. Engine dynamometer testing demonstrated that autogas produced similar performance characteristics to gasoline at part load, but could be used to improve brake thermal efficiency at loads above 12 bar BMEP.
2017-03-28
Technical Paper
2017-01-0685
Michael Clifford Kocsis, Thomas Briggs, Garrett Anderson
To evaluate the impact of common lubricant additives on the frequency of low-speed pre-ignition (LSPI), a statistically-relevant test method was developed and used to evaluate purpose-blended lubricants which allowed isolation of specific additive compounds. For the present work, the levels of zinc dialkyldithiophosphate (ZDDP), calcium sulfonate, and molybdenum were varied roughly between the minimum and maximum levels expected in modern passenger car motor oil formulations. The results showed a strong positive correlation between the level of calcium sulfonate and the LSPI rate, and that near-zero LSPI frequency could be achieved at the lowest concentrations of the additive. Replacing calcium sulfonate with magnesium sulfonate also generated near-zero LSPI frequency, even with a normal additive concentration. The other additives under evaluation showed mild negative correlations between additive concentration and LSPI rate.
2017-03-28
Technical Paper
2017-01-0766
Gary D. Neely, Radu Florea, Jason Miwa, Zainal Abidin
Although low diesel fuel prices have reduced the appeal of natural gas (NG) engines recently, the CO2 advantage and low NOX and PM potential of NG makes it well-suited for meeting future greenhouse gas (GHG) and potential lower NOX regulations for on-road medium and heavy-duty engines. However, traditional NG fueling strategies and/or poor air/fuel ratio control can result in significant levels of tailpipe methane (CH4) emissions which offset the CO2 advantage due to the high global warming potential of CH4. 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 shown to improve the brake thermal and combustion efficiencies over equivalent fumigated dual-fuel combustion modes in a previous publication.
2017-03-28
Technical Paper
2017-01-1095
Sankar B. Rengarajan, Jayant Sarlashkar, Peter Lobato
Strict government regulation of green house gases, rising corporate average fuel economy standards and high customer expectation of performance have prompted vehicle manufacturers to consider all technology options. Overall efficiency of a vehicle drivetrain can be improved by optimizing component performance – and transmission, regardless of its type, is a key component of the drivetrain. SAE Recommended Practice J1540 specifies test procedures to map torque transmission efficiency and parasitic losses in a manual transmission. The procedure comprises two parts. The first compares input and output torque over a range of speed to determine efficiency. The second measures parasitic losses at zero input torque over a range of speed. As specified in J1540, efficiency of transmissions is routinely measured on a test-stand under steady torque and speed.
2017-03-28
Technical Paper
2017-01-0956
Christopher Sharp, Cynthia C. Webb, Seungju Yoon, Michael Carter, Cary Henry
Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr. However, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOx emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOx emissions. This paper details the work done to explore the feasibility of various configurations of Traditional Technology (diesel oxidation catalyst-diesel particulate filter-selective catalytic reduction (SCR)) and Advanced Technology (passive NOx adsorber or diesel oxidation catalyst – SCR on Filter – SCR) to demonstrate ultra-low NOx emissions from heavy-duty engines.
2017-03-28
Technical Paper
2017-01-0954
Christopher Sharp, Seungju Yoon, Gary Neely, Michael Carter, Cynthia C. Webb, Cary Henry
Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr. However, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOx emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOx emissions. This paper details cold and hot-start FTP thermal management requirements to achieve ultra-low NOX levels with a turbocompound engine. Additionally, the energy requirements of various aftertreatment configurations were explored and data will be presented to highlight the impact of turbocompounding on cold-start emissions.
2017-03-28
Technical Paper
2017-01-0958
Christopher Sharp, Seungju Yoon, Gary Neely, Cynthia C. Webb, Cary Henry, Bryan Zavala
Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr. However, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOx emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOx emissions. This paper details engine and aftertreatment NOX management requirements and model based control considerations for achieving Ultra-Low NOX levels. Data will be presented for several Advanced Technology aftertreatment technologies and the integration of those technologies with the engine calibration.
2017-03-28
Technical Paper
2017-01-0533
Paul Dekraker, Mark Stuhldreher, Youngki Kim
The Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of all internal energy flows in the model. The software tool is a MATLAB/Simulink based application. In preparation for the midterm evaluation (MTE) of the 2017-2025 light-duty GHG emissions rule, ALPHA has been refined and revalidated using newly acquired data from model year 2013-2015 engines and vehicles. The vehicle and engine testing for the MTE coupled with further validation of the ALPHA model has highlighted some areas where additional accuracy can be achieved by adding fidelity to the engine model within ALPHA.
2016-10-17
Technical Paper
2016-01-2327
Scott Eakle, Svitlana Kroll, Cary Henry
Abstract Ideally, complete decomposition of urea should produce only two products in active Selective Catalytic Reduction (SCR) systems: ammonia and carbon dioxide. In reality, urea decomposition reaction is a two-step process that includes the formation of ammonia and isocyanic acid as intermediate products via thermolysis. Being highly reactive, isocyanic acid can initiate the formation of larger molecular weight compounds such as cyanuric acid (CYN), biuret (BIU), melamine (MEL), ammeline (AML), ammelide (AMD), and dicyandimide (DICY). These compounds can be responsible for the formation of deposits on the walls of the decomposition reactor in urea SCR systems. Composition of these deposits varies with temperature exposure, and under certain conditions can create oligomers that are difficult to remove from exhaust pipes.
2016-10-17
Technical Paper
2016-01-2269
Peter Morgan, Alexander Michlberger, Michael Kocsis, Matt Gieselman, Ewan Delbridge
Abstract Chassis dynamometer tests are often used to determine vehicle fuel economy (FE). Since the entire vehicle is used, these methods are generally accepted to be more representative of ‘real-world’ conditions than engine dynamometer tests or small-scale bench tests. Unfortunately, evaluating vehicle fuel economy via this means introduces significant variability that can readily be mitigated with engine dynamometer and bench tests. Recently, improvements to controls and procedures have led to drastically improved test precision in chassis dynamometer testing. Described herein are chassis dynamometer results from five fully formulated engine oils (utilizing improved testing protocols on the Federal Test Procedure (FTP-75) and Highway Fuel Economy Test (HwFET) cycles) which not only show statistically significant FE changes across viscosity grades but also meaningful FE differentiation within a viscosity grade where additive systems have been modified.
2016-10-17
Technical Paper
2016-01-2170
Raphael Gukelberger, Dennis Robertson, Terrence Alger, Steven Almaraz, Jess Gingrich, Vijayakannan Mohan
Abstract A turbocharged 2.0 L PFI engine was modified to operate in a low-pressure loop and Dedicated EGR (D-EGR®) engine configuration. Both engine architectures were operated with a low and high octane gasoline as well as three ethanol blends. The core of this study focused on examining combustion differences at part and high loads between the selected fuels and also the different engine configurations. Specifically, the impact of the fuels on combustion stability, burn rates, knock mitigation, required ignition energy, and efficiency were evaluated. The results showed that the knock resistance generally followed the octane rating of the fuel. At part loads, the burn rates, combustion stability, and EGR tolerance was marginally improved with the high ethanol blends. When combustion was not knock or stability limited, the efficiency differences between the fuels were negligible. The D-EGR engine was much less sensitive to fuel changes in terms of burn rates than the LPL EGR setup.
2016-10-17
Journal Article
2016-01-2177
Kevin L. Hoag, Barrett Mangold, Terrence Alger, Zainal Abidin, Christopher Wray, Mark Walls, Christopher Chadwell
Abstract A unique single cylinder engine was used to assess engine performance and combustion characteristics at three different strokes, with all other variables held constant. The engine utilized a production four-valve, pentroof cylinder head with an 86mm bore. The stock piston was used, and a variable deck height design allowed three crankshafts with strokes of 86, 98, and 115mm to be tested. The compression ratio was also held constant. The engine was run with a controlled boost-to-backpressure ratio to simulate turbocharged operation, and the valve events were optimized for each operating condition using intake and exhaust cam phasers. EGR rates were swept from zero to twenty percent under low and high speed conditions, at MBT and maximum retard ignition timings. The increased stroke engines demonstrated efficiency gains under all operating conditions, as well as measurably reduced 10-to-90 percent burn durations.
2016-10-17
Journal Article
2016-01-2330
E. Robert Fanick, Svitlana Kroll, Kristin Favela
Abstract Advanced combustion strategies used to improve efficiency, emissions, and performance in internal combustion engines (IC) alter the chemical composition of engine-out emissions. The characterization of exhaust chemistry from advanced IC engines requires an analytical system capable of measuring a wide range of compounds. For many years, the widely accepted Coordinating Research Council (CRC) Auto/Oil procedure[1,2] has been used to quantify hydrocarbon compounds between C1 and C12 from dilute engine exhaust in Tedlar polyvinyl fluoride (PVF) bags. Hydrocarbons greater than C12+ present the greatest challenge for identification in diesel exhaust. Above C12, PVF bags risk losing the higher molecular weight compounds due to adsorption to the walls of the bag or by condensation of the heavier compounds. This paper describes two specialized exhaust gas sampling and analytical systems capable of analyzing the mid-range (C10 - C24) and the high range (C24+) hydrocarbon in exhaust.
2016-09-27
Technical Paper
2016-01-8009
Michael Brown, Purser Sturgeon
Abstract While initial Connected Vehicle research in the United States was focusing almost exclusively on passenger vehicles, a program was envisioned that would enhance highway safety, mobility, and operational efficiencies through the application of the technology to commercial vehicles. This program was realized in 2009 by funding from the I-95 Corridor Coalition, led by the New York State Department of Transportation, and called the Commercial Vehicle Infrastructure Integration (CVII) program. The CVII program focuses on developing, testing and deploying Connected Vehicle technology for heavy vehicles. Since its inception, the CVII program has developed numerous Vehicle-to-Vehicle and Vehicle-to-Infrastructure applications for trucks that leverage communication with roadside infrastructure and other light and heavy duty vehicles to meet the objectives of the program.
2016-09-27
Journal Article
2016-01-8007
Chris Mentzer, Ryan D. Lamm, Jerry Towler
Abstract Since the turn of the millennium, automated vehicle technology has matured at an exponential rate, evolving from research largely funded and motivated by military and agricultural needs to a near-production market focused on everyday driving on public roads. Research and development has been conducted by a variety of entities ranging from universities to automotive manufacturers to technology firms demonstrating capabilities in both highway and urban environments. While this technology continues to show promise, corner cases, or situations outside the average driving environment, have emerged highlighting scenarios that impede the realization of full automation anywhere, anytime. This paper will review several of these corner cases and research deficiencies that need to be addressed for automated driving systems to be broadly deployed and trusted.
2016-09-27
Journal Article
2016-01-8018
Houshun Zhang, L. James Sanchez, Matthew Spears, Jayant Sarlashkar, Dennis Robertson, Michael Ross
Abstract In June of 2015, the Environmental Protection Agency and the National Highway Traffic Safety Administration issued a Notice of Proposed Rulemaking to further reduce greenhouse gas emissions and improve the fuel efficiency of medium- and heavy-duty vehicles. The agencies proposed that vehicle manufacturers would certify vehicles to the standards by using the agencies’ Greenhouse Gas Emission Model (GEM). The agencies also proposed a steady-state engine test procedure for generating GEM inputs to represent the vehicle’s engine performance. In the proposal the agencies also requested comment on an alternative engine test procedure, the details of which were published in two separate 2015 SAE Technical Papers [1, 2]. As an alternative to the proposed steady-state engine test procedure, these papers presented a cycle-average test procedure.
2016-04-05
Technical Paper
2016-01-0067
Ryan Wilson, Wayne Music, Brian Anderson
Modern vehicular systems rely on millions of lines of code that must occasionally be updated to add new functions or to patch flaws to ensure safe and secure operation. Updates accomplished through a compromised cellular base station could lead to an update process that may be vulnerable to attack. We have been investigating techniques for determining whether an LTE base station (known as an eNodeB) appears to be suspicious, so that an update could be paused or terminated until a trusted eNodeB is available. We describe a detector we developed as part of our research that scans LTE signals for anomalies and provides an alert when an anomaly is found.
2016-04-05
Technical Paper
2016-01-0600
Zainal Abidin, Kevin Hoag, Douglas Mckee, Nicholas Badain
Abstract The engine intake process governs many aspects of the flow within the cylinder. The inlet valve is the minimum area, so gas velocities at the valve are the highest velocities seen. Geometric configuration of the inlet ports and valves, and the opening schedule create organized large scale motions in the cylinder known as swirl and tumble. Good charge motion within the cylinder will produce high turbulence levels at the end of the compression stroke. As the turbulence resulting from the conversion energy of the inlet jet decays fast, the strategy is to encapsulate some of the inlet jet in the organized motions. In this work the baseline port of a 2.0 L gasoline engine was modified by inserting a tumble plate. The work was done in support of an experimental study for which a new single-cylinder research engine was set up to allow combustion system parameters to be varied in steps over an extensive range. Tumble flow was one such parameter.
2016-04-05
Technical Paper
2016-01-0616
Jayant Sarlashkar, Sankar Rengarajan, Ryan Roecker
Abstract Southwest Research Institute (SwRI) has successfully demonstrated the cooled EGR concept via the High Efficiency Dilute Gasoline Engine (HEDGE) consortium. Dilution of intake charge provides three significant benefits - (1) Better Cycle Efficiency (2) Knock Resistance and (3) Lower NOx/PM Emissions. But EGR dilution also poses challenges in terms of combustion stability, condensation and power density. The Dedicated EGR (D-EGR) concept brings back some of the stability lost due to EGR dilution by introducing reformates such as CO and H2 into the intake charge. Control of air, EGR, fuel, and ignition remains a challenge to realizing the aforementioned benefits without sacrificing performance and drivability. This paper addresses the DEGR solution from a controls standpoint. SwRI has been developing a unified framework for controlling a generic combustion engine (gasoline, diesel, dual-fuel natural gas etc.).
2016-04-05
Technical Paper
2016-01-0636
Kevin L. Hoag, Anthony Megel
Abstract The objective of this work was to develop a methodology to rapidly assess comparative intake port designs for their capability to produce tumble flow in spark-ignition engine combustion chambers. Tumble characteristics are of relatively recent interest, and are generated by a combination of intake port geometry, valve lift schedule, and piston motion. While simple approaches to characterize tumble from steady-state cylinder head flow benches have often been used, the ability to correlate the results to operating engines is limited. The only available methods that take into account both piston motion and valve lift are detailed computational fluid dynamic (CFD) analysis, or optical measurements of flow velocity. These approaches are too resource intensive for rapid comparative assessment of multiple port designs.
2016-04-05
Technical Paper
2016-01-0595
Zainal Abidin, Radu Florea, Timothy Callahan
Abstract The current boom in natural gas from shale formations in the United States has reduced the price of natural gas to less than the price of petroleum fuels. Thus it is attractive to convert high horsepower diesel engines that use large quantities of fuel to dual fuel operation where a portion of the diesel fuel is replaced by natural gas. The substitution is limited by emissions of unburned natural gas and severe combustion phenomena such as auto-ignition or knock of the mixture and high rates of pressure rise during the ignition and early phase combustion of the diesel and natural gas-air mixture. In this work, the combustion process for dual fuel combustion was investigated using 3D CFD. The combustion process was modeled using detailed chemistry and a simulation domain sensitivity study was conducted to investigate the combustion to CFD geometry assumptions.
2016-04-05
Technical Paper
2016-01-0728
Daniel Christopher Bitsis, Charles Roberts, Jason Miwa, Christopher Chadwell, Sankar Rengarajan
Abstract There are numerous off-road diesel engine applications. In some applications there is more focus on metrics such as initial cost, packaging and transient response and less emphasis on fuel economy. In this paper a combustion concept is presented that may be well suited to these applications. The novel combustion concept operates in two distinct operation modes: lean operation at light engine loads and stoichiometric operation at intermediate and high engine loads. One advantage to the two mode approach is the ability to simplify the aftertreatment and reduce cost. The simplified aftertreatment system utilizes a non-catalyzed diesel particulate filter (DPF) and a relatively small lean NOx trap (LNT). Under stoichiometric operation the LNT has the ability to act as a three way catalyst (TWC) for excellent control of hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx).
2016-04-05
Technical Paper
2016-01-0779
Radu Florea, Gary D. Neely, Zainal Abidin, Jason Miwa
Abstract For the US market, an abundant supply of natural gas (NG) coupled with recent green-house gas (GHG) regulations have spurred renewed interest in dual-fuel combustion regimes. This paper explores the potential of co-direct injection to improve the efficiency and reduce the methane emissions versus equivalent fumigated dual-fuel combustion systems. Using the Westport HPDI engine as the experimental test platform, the paper reports the results obtained using both diffusion controlled (HPDI) combustion strategy as well as a partially-premixed combustion strategy (DI2). The DI2 combustion strategy shows good promise, as it has been found to improve the engine efficiency by over two brake thermal efficiency (BTE) points (% fuel energy) compared to the diffusion controlled combustion strategy (HPDI) while at the same time reducing the engine-out methane emissions by 75% compared to an equivalent fumigated dual-fuel combustion system.
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