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Emission control particulate matter
Contaminants' effects on diesel emissions
Cassini marks milestone
SwRI's Ryan named Fellow of SAE
Oort Cloud smaller than once thought
SwRI corrosion expert named Fellow of NACE
Hybrid powertrain undergoes fuel test

Emission control particulate matter

Engine emissions researchers at Southwest Research Institute (SwRI) are forming a consortium to examine how technologies aimed at reducing oxides of nitrogen (NOx) from diesel engines affect the emissions of particulate matter. 

Titled, "The Effect of Emission Control Technologies on the Chemical and Physical Properties of Diesel Particulate," the new consortium will research the impact of various current as well as novel NOx and particulate matter control technologies on the chemical and physical characteristics of particles emitted from diesels. 

Emphasis will be placed on in-cylinder methods as well as post-combustion emissions reduction devices. For NOx reduction, exhaust gas recirculation (EGR) and water emulsions will be among methods considered.

In addition, lean NOx traps (NOx adsorbers), and selective catalytic reduction (SCR) systems with urea are a sample of what SwRI intends to include in the test matrix. For control of particulate matter, diesel oxidation catalysts in combination with diesel particulate filters will be included. The end result of combining these post-combustion systems together with in-cylinder controls is to achieve NOx/particulate emission levels that approach those proposed by the U.S. Environmental Protection Agency (EPA) for 2007.

The scope of work will include a detailed gaseous and particulate matter chemical and physical characterization for a production engine. This work will not be limited to regulated emissions (hydrocarbons, carbon monoxide, NOx, and total particulate matter), but will include a substantial list of unregulated emissions. From the chemical standpoint, the program will address soluble and insoluble fractions, sulfate and retained water, aldehydes and ketones, polycyclic aromatic hydrocarbons, cyanide, ammonia, nitrous oxide, hydrogen sulfide, trace metals and hydrocarbon speciation.

As for the physical characteristics of particulate matter, a complete and thorough analysis of ultrafine and nanoparticle distribution will be conducted. This analysis will focus on particle count and size using specialized equipment such as the scanning mobility particle sizer, electrical low-pressure impactor micro-orifice

Contaminants' effects on diesel emissions

A new research consortium being formed at Southwest Research Institute (SwRI) aims to discover the extent to which certain common lubricating oil components can poison or degrade diesel exhaust aftertreatment devices. 

The consortium, titled "Diesel Aftertreatment Sensitivity to Lubricants (DASL)," is examining the impact of sulfur in lubricants and studying other components including zinc, calcium, barium, magnesium, and phosphorus. 

Sulfur in motor oil can originate from crude oil as well as from anti-oxidant and anti-wear additives. Any of those components might degrade the performance of diesel NOx traps, urea- or ammonia-SCR systems, continuously regenerating soot traps, catalyzed soot traps and diesel oxidation catalysts.

Research from this parametric, or cause-and-effect, study could indicate that some systems can tolerate the presence of lube components or additives within some acceptable range, while other systems might be found to be especially sensitive to poisoning.

The consortium is designed to help diesel engine manufacturers, petroleum product manufacturers and emissions control suppliers. Cost is $75,000 per year, renewable annually. 

Contact Bruce Bykowski at (210) 522-2937 or bbykowski@swri.org.

Cassini marks milestone

The Cassini spacecraft marked another milestone on its seven-year voyage to Saturn when it passed within 6 million miles of Jupiter on Dec. 30, 2000. The encounter came during a gravity assist maneuver designed to speed Cassini along towards its rendezvous with Saturn in the summer of 2004. Cassini was launched in October 1997. 

SwRI's Space Science and Engineer-ing Division developed and built a large part of the Cassini Plasma Science (CAPS) instrument and has been involved in the ground systems development and flight portions of both CAPS and the Ion and Neutral Mass Spectrometer (INMS), another Cassini instrument.

CAPS is designed to study the dynamics and composition of the solar wind and Saturn's plasma, while INMS will measure the composition of the neutral and ionized gases in the Saturn environment. The University of Michigan is the lead institution for both the CAPS and INMS instruments.

The CAPS instrument was operational in September 2000 and began measuring the solar wind and the Jovian magnetospheric plasma. Although the data have not been analyzed fully, preliminary results show that the instrument performed flawlessly. Measurements show the transition from the relatively cold solar wind plasma upstream of Jupiter into the much hotter plasma after Cassini entered the Jovian magnetosphere and continued down the magnetotail.

 

SwRI's Ryan named Fellow of SAE

Thomas W. Ryan III of the Engine and Vehicle Research Division has been named a Fellow of the Society of Automotive Engineers (SAE). Ryan was recognized for the achievement at the 2001 SAE International Congress and Exposition held March 5-8 in Detroit.

Ryan was selected for the honor because of his knowledge of the impact of fuel quality on combustion and emissions, particularly, compression ignition combustion. Since 1976, SAE has selected only 428 of its 80,000 members to receive the honor. Candidates must have been SAE members for at least 10 years.

A specialist in fuels and combustion technology, Ryan came to SwRI in 1979. Much of his work involves the application of diagnostic techniques in experiments involving both real and simulated combustion environments, including the use of constant volume devices and flow reactors to study diesel fuel injection, and the use of high-speed cylinder pressure data acquisition for the study of combustion in diesel engines.

His interest in fuels includes the use of coal, both dry powder and slurried, in a variety of liquid carriers; coal and shale-oil-derived liquids fuels; vegetable oil and hydrocarbon-type crop fuels; alcohols; and a variety of hydrocarbon liquids and gases.
He is the inventor of U.S. Patent, No. 5,753,806, "Apparatus and Method for Determining the Distribution and Flow Rate Characteristics of an Injection Nozzle," and is co-inventor of three others: No. 4,873,947, "Variable Compression Ratio Direct Injection Engine," No. 5,297,515, "Fuel Supply Systems for Engines and Combustion Processes Therefor," and No. 5,339,634, "Fuel Supply System for Engines and Combustion Processes Therefor."

Oort Cloud smaller than once thought

Many comets once thought to have been ejected into the Oort Cloud during the early formation of the solar system are now believed to have been pulverized in violent collisions among themselves. 

The finding, by researchers at Southwest Research Institute (SwRI) and the Jet Propulsion Laboratory (JPL), demonstrates that previous models of Oort Cloud formation may have overestimated the mass of the giant sphere far beyond the planets in which comets are thought to reside.

In work described in the Feb. 1 issue of Nature, Dr. Alan Stern (SwRI) and Dr. Paul Weissman (JPL) showed that, contrary to a long-standing assumption, the ejection of comets to the Oort Cloud during and just after the formation of the giant planets was a violent process. Stern and Weissman's computer models show that most comets and smaller debris present between the outer planets during the so-called "clearing phase" of outer solar system formation were destroyed in mutual collisions before they could be ejected to the Oort Cloud by the strong gravity of the giant planets.

Previous Oort Cloud formation models neglected the effects of these collisions. 

"One implication of these results is that, because collisions introduced additional inefficiencies in Oort Cloud formation, the cloud may be 10 times less massive than previously thought," Weissman said.

"Another apparent implication," Stern said, "is that the comets in the Oort Cloud could be smaller and quite likely more heavily damaged as a result of these collisions than many had thought. Our results, along with those recently obtained by others, are revealing that both comet and Oort Cloud formation are more complex processes than had previously been suspected. It's a new ball game now."

SwRI corrosion expert named Fellow of NACE

Dr. Gustavo A. Cragnolino, a staff scientist in the Center for Nuclear Waste Regulatory Analyses, a Nuclear Regulatory Commission facility located at and operated by Southwest Research Institute (SwRI), has been named a Fellow of NACE International, formerly the National Association of Corrosion Engineers.

Cragnolino, an NACE International member for more than 24 years, was selected for his contribution to corrosion research areas related to nuclear power generation and radioactive waste disposal systems.

A specialist in the electrochemical corrosion of metals in high-temperature, high-pressure aqueous systems, Cragnolino came to SwRI in 1990 following employment at the Comisión Nacional de Energía Atómica in Argentina. While at the Fontana Corrosion Center at the Ohio State University and Brookhaven National Laboratory, he applied and developed experimental techniques for the study of stress corrosion cracking of austenitic stainless steels and nickel-based alloys in aqueous solutions and nodular corrosion of zirconium alloys in superheated steam.

For the past 10 years, his work has concentrated on localized corrosion, galvanic corrosion, stress corrosion cracking, and thermal stability of metallic container materials for high-level radioactive waste disposal, combined with the modeling of long-term degradation of waste packages caused by environmental effects.

Contact Cragnolino at (210) 522-5539 or gcragnolino@swri.org.

Hybrid powertrain undergoes fuel test

A parallel hybrid gasoline-electric powertrain for medium-size cars, developed by engineers at Southwest Research Institute (SwRI), achieved an average fuel economy of 79 miles per gallon using the Federal Test Procedure (FTP) to emulate highway and city driving.

Dynamometer tests of the Parallel Hybrid Electric Combination of Speeds (PECOS) powertrain were conducted to determine full acceleration performance and fuel economy over the urban and highway driving profiles. 

The PECOS powertrain accelerates a vehicle with a mass of 1,265 kilograms, aerodynamic drag coefficient of 0.34, and frontal area of 2m2 from zero to 60 miles per hour in 14.9 seconds.

The powertrain achieved fuel economy of 77 miles per gallon for city driving and 82 miles per gallon for highway driving, resulting in an average fuel economy of 79 miles per gallon.

SwRI engineers recently completed prototyping and testing of the patented hybrid powertrain. Its simple design consists of off-the-shelf components, including a 40 kW (peak), 1-liter spark ignition engine, a 53 kW (peak) and 32 kW (continuous) permanent magnet brushless DC motor, a power splitting planetary gear box, and a lead acid battery pack (312 volt bus).

The planetary gearbox contains one sprag (one-way) clutch and one wet clutch. The sprag clutch and wet clutch transition the PECOS powertrain from one mode of operation to another. Four operating modes are possible: pure electric, a battery pack charge mode, motor assisted engine, and regenerative braking.

The controller automatically switches the powertrain from one mode of operation to another using a fuzzy logic rule-based strategy based on road conditions. This control strategy minimizes mode transition instabilities.

The PECOS system has several advantages over conventional powertrains. It does not require a clutch to launch the vehicle - the motor can spin backward until the drive wheels are engaged. The engine does not require a starter, since the electric motor starts the engine. Finally, no transmission is required except for a differential.

Published in the Spring 2001 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Maria Stothoff.

Spring 2001 Technology Today
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