Technical Highlights for September 2015
General Motors (GM) and the Oak Ridge National Laboratory (ORNL) receive the
Department of Energy (DOE) ASCR Leadership Computing Challenge (ALCC)
Award on Titan for Diesel Calibration Study
Ron Grover and Ramachandra Diwakar of GM and Dean Edwards and Wael Elwasif of
ORNL received a DOE ALCC allocation for 8M processor-hours on Titan to explore the
feasibility of developing a steady-state engine calibration using high-performance
computing and a virtual engine modeled using state-of-the-art computational fluid
dynamic (CFD) tools. GM and ORNL will use commercial 1-D and CFD engine
simulation tools GT-Suite and CONVERGE (with graphics processing unit (GPU)-
enabled chemistry solvers developed by Lawrence Livermore National Laboratory
(LLNL)) to construct the virtual engine model. ORNL’s TASMANIAN software toolkit
for adaptive sparse-grid sampling and uncertainty quantification and Sandia National
Laboratories’ (SNL’s) DAKOTA optimization toolkit will be employed to manage
parameter sampling for the virtual engine simulations and optimize calibration of key
engine parameters (e.g., boost, exhaust gas recirculation (EGR), air-fuel ratio, rail
pressure, fuel injection quantities and timings, etc.) across the full engine operation
map. If successful, virtual engine calibration could lead to significant cost and time
reductions in the development of new engine calibrations by greatly reducing the
number of on-engine experiments required. This new effort is part of a continuing
collaboration between GM and ORNL to utilize high-performance computing and CFD
simulation to accelerate design, development, and deployment of advanced engines
capable of meeting future efficiency and emissions goals.
Arctic Black Carbon (BC) Project Finishes with International Workshop and New
John Storey and Vitaly Prikhodko of the Fuels, Engines, and Emissions Research Center (FEERC) wrapped up a four-year project this month on assessment and mitigation of BC emissions transport to the Arctic. The State Department-funded project focused on Russian sources of BC from industry and the power sector. The project was a collaborative effort both within the laboratory (Energy and Environmental Sciences Directorate (EESD) researchers Mengdawn Cheng, Michael Hilliard, and Rick Goeltz) and external to the laboratory (DOE, the University of Tennessee, SRI Atmosphere of St. Petersburg, Russia). In addition to emissions modeling and analysis, a geographic visualization tool using Tableau was constructed that allows the user to interactively view different scenarios for lowering BC emissions from Russia on a regional basis, or by industrial sector. The culmination of the project was a workshop on Arctic BC held in Milan, Italy, with participation from more than 80 people representing 20 countries in Europe, North America, and Asia. The project findings are in three journal publications, an ORNL report, and a website, http://abci.ornl.gov/index.shtml, which contains all of the written materials as well as the interactive visualization tool.
FEERC Researchers Evaluate “Emerging” Vehicles to Update Fuel Economy
versus Speed Database
FEERC researchers have been collecting fuel economy data for a wide range of vehicles at highway cruise conditions in support of the fueleconomy.gov website. Models have been developed that are the basis of a tool on fueleconomy.gov that predicts highway fuel economy penalty as a function of speed. The original study included various sizes of 2003–2012 sedans, wagons, hybrids, SUVs, pickup trucks, minivans, and sports cars from multiple manufacturers. Driven by the Corporate Average Fuel Economy (CAFÉ) rule, vehicle fuel economy dramatically improves each year. While certification data for specific cycles are available, there are no public data available for fuel economy under steady speed cruise conditions. This month a pair of Chevrolet Spark vehicles were evaluated, one with a manual transmission, and one with a continuously variable transmission (CVT). The CVT Spark’s engine speed was significantly lower under cruise conditions from 40–80 mph. This downspeeding enabled improved fuel economy up to about 55 mph, but at 60 mph and higher the two vehicles were virtually identical. This result implies that the higher engine efficiency from downspeeding was overcome by higher transmission losses at the higher vehicle speeds. In addition, a Jeep Cherokee and a Chrysler 200 were evaluated. Both vehicles feature the 2.4 liter I4 engine with a 9 speed automatic transmission. Both vehicles returned excellent fuel economy. It was interesting to note that the Cherokee only used 9th gear when driving on a slight downgrade.
HIGH-LEVEL OR NOTEWORTHY VISITS
Advanced Research Projects Agency-Energy (ARPA-E) Program Manager Tours FEERC, Power Electronics and Electric Machinery Research Center (PEEM), and Manufacturing Demonstration Facility (MDF)
Dr. James Klausner from ARPA-E visited ORNL this month. Dr. Klausner leads the Modern Electro/Thermochemical Advances in Light Metals Systems Program. His ORNL host was Dr. Ayyoub Momen and he visited the main campus and the Hardin Valley Campus touring FEERC, PEEM, and MDF.
INVITED TALKS AND PRESENTATIONS
FEERC Researcher Delivers Invited Presentation at the Society of Automotive Engineers (SAE) Gasoline Compression Ignition Symposium
FEERC Researcher Derek Splitter presented work led by FEERC post-doc Adam Dempsey and FEERC Researcher Scott Curran at the 2015 SAE Gasoline Compression Ignition Symposium in Capri, Italy. The symposium was attended by automotive manufacturers and researchers, petroleum refiners and producers, and regulatory members. A focus of the symposium was to address the modes to achieve gasoline compression ignition and the opportunities and challenges that exist ranging from technical to practical that must be addressed. The work presented by FEERC directly illustrated the context of the symposium as it discussed the challenges and opportunities of a wide spectrum of gasoline compression ignition (GCI) combustion modes and fuel selections, which have been under investigation with examples from current multi-cylinder engine research at ORNL. The results illustrated that both fuel and combustion research needed to be simultaneously investigated as potential pathways for reducing fuel consumption, and that fuel properties, engine performance and fuel consumption are highly related.
FEERC Researcher Delivers Invited Webinar on Historical Analysis of the Co-Evolution of Light-Duty Fuels and Engines to American Society for Testing and Materials (ASTM) Fuel Octane Working Group
FEERC researcher Derek Splitter was invited to present results to the ASTM Fuel Octane working group from a deep literature review encompassing engine, vehicle, and fuel data since 1925. The findings examined historical and recent coupling between compression ratio and fuel antiknock properties (i.e., octane number) in the U.S. light-duty vehicle market. The analysis identified historical timeframes, trends, and illustrated how three factors: consumer preferences, technical capabilities, and regulatory legislation affect personal mobility. Data showed that throughout history these three factors have a complex and time sensitive interplay. Long term trends in the data were identified where interaction and evolution between all three factors was observed. Specifically, transportation efficiency per unit power (gal/ton-mi/hp) was found to be a good metric to integrate technical, societal, and regulatory effects into the evolutional pathway of personal mobility. From this framework, discussions of future evolutionary changes to personal mobility are also presented, including potential opportunities to increase fuel octane though bio-fuels.
ORNL Emissions Control Technical Lead gives Plenary Lecture at the 4th International Symposium on Modeling of Exhaust-Gas After-Treatment (MODEGAT IV)
Todd J. Toops gave the Plenary Lecture/Tutorial on selective catalytic reduction (SCR) at MODEGAT IV in Bad Herrenalb, Germany. The presentation, “The Measured and Proposed Chemistry of the Selective Catalytic Reduction of NOx,” covered recent advances in experimental techniques and a detailed assessment of the current models being proposed for SCR chemistry. The European-based conference draws from both industry and academia to discuss the latest modeling efforts in exhaust gas aftertreatment. Additionally, Dr. Toops gave invited presentations at Politecnico di Milano in Italy and the Karlsruhe Institute of Technology in Germany.
FEERC Contributes to Invited Research Presented at the 2015 Massachusetts Institute of Technology (MIT) Consortium
An invited presentation entitled “Impact of Metal Impurities in Biodiesel on Catalyst Durability” by Michael J. Lance, Todd J. Toops, and Andrew A. Wereszczak was presented at the invitation-only MIT Consortium to Optimize Lubricant & Diesel Engines for Robust Emission Aftertreatment Systems on September 29, 2015, in Cambridge, Massachusetts. Discussions regarding future collaborations with ORNL were held with consortium members and MIT staff.