Technology Bulletin

Look inside a diesel engine uncovers some misconceptions

What goes on inside a diesel combustion engine is not what researchers once thought. A specially designed research engine with windows in the combustion chamber has given scientists at Sandia National Laboratories and Cummins Engine Co. a unique view of the process. And the researchers found that the classic combustion model performs differently than was anticipated. The old model depicted a simple diffusion flame with soot forming only around the periphery of the fuel jet. The new picture, which also involved the use of computer modeling and laser diagnostics, shows that fuel and air mixing, combustion, and soot formation occur progressively as the fuel moves down the reacting jet. The researchers goal: to build a more accurate model in an attempt to develop a cleaner, more efficient engine. FAX (505) 844-6367.

Novel airbag offers more safety options, design flexibility

Another Sandia National Laboratories project, a "revolutionary" airbag, could result in safer automobiles. The Precision Technology Airbag™, a joint design effort between Sandia and Precision Fabrics Group (PFG), Inc., Greensboro, NC, inflates to the same size as conventional devices, but is less than half the packed volume and weight. The team of engineers used computer modeling, structural analysis techniques, and lab facilities normally used to develop high-tech parachutes to evaluate every aspect of the airbag. The analysis showed that the greatest stresses on the conventional airbag occurred at the "equator," the seam joining the bag's two circular halves. Through their joint efforts, Sandia and PFG learned how to produce the optimal design and fabric. The resulting product, they claim, is easier to make, while still providing the needed protection. "There is not an ounce too much fabric or stitching in the design," says Sandia Project Manager Carl Peterson. When folded, the new airbag could fit into the pocket of a man's shirt, but "it still provides equivalent amounts of body coverage and protection as conventional units," Peterson adds. FAX (505) 844-6367.

Metal matrix coating technology could reduce auto emissions

Advanced Refractory Technologies (ART), Buffalo, NY, has received an award from the New York State Energy Research and Development Authority to develop ceramic reinforcements for metal matrix composites based on a surface-treatment technology developed by Clarkson University. The project will combine ART's commercial silicon carbide whiskers (SiCw) and Clarkson's coating technology to reinforce aluminum and magnesium for use in automobile-engine and other components. "If these coated whisker materials are successfully used in aluminum for pistons," says Donald J. Bray, ART's director of technology, "the resulting piston could minimize unburned hydrocarbons and significantly reduce auto emissions." The $100,000 award will enable ART to scale up the coating fundamentals developed by Professor Richard Partch of Clarkson's Center for Advanced Materials Processing. FAX (716) 875-0106 .

Clean 'green' machine tackles dirty automotive parts

Auto dealers and service shops now have a kinder, gentler way to clean auto parts--the SmartWasher. Developed by ChemFree Corp., Norcross, GA, the washer uses enzymes to break down oil, grease, and other contaminants, without producing hazardous wastes. The unit holds 20 gallons of the water-based cleaning solution at 105F, and has a sink large enough to clean a transmission case. The filter beneath the sink traps larger particles, while smaller debris flows into the basin, where the enzymes convert the grease and oil into water and carbon dioxide. The washer continuously cleans and recycles the solution. Users can lease the unit for about $1,500 a year. Fluid and filters run about $40 a month. "That's far less than conventional parts washers that cost anywhere from $95 to $150 a month to service," says Thomas McNally, ChemFree general manager. FAX (770) 564-5533.

Thick-film technology combats vehicle electrical problems

Spectrol Electronics, Ontario, CA, has developed a thick-film technology it claims can produce digital encoders that are more reliable than typical mechanical versions, and for about one-half the price of optical encoders. One of the major advantages of the Silver-in-Glass™ technology involves minimizing the step-height differential between the conductor and insulator surface. Designs that use a composite board with copper foil etching normally have a "bump up" contact intersection on the order of 25-35 microns. This not only creates wear life and electrical noise problems, but the circuit board material may have dimensional instability that results in switching accuracy failures. By contrast, the Spectrol material system deposits a thick film of glass over an alumina ceramic substrate, virtually eliminating the step-height differential. Several automotive applications have benefited from the technology. Among them: gear-shift position sensing and control and transmission speed indication. FAX (909) 923-6765.

Automotive-scale fuel cell undergoes testing

Fuel cells, devices that convert chemical energy to electrical energy without combustion, fairly common in the space program, have not provided sustained power at a reasonable cost and size for use in the automotive industry--until now. Researchers at Los Alamos National Laboratory have started testing an automotive-scale fuel cell as part of the second phase of a joint project with General Motors and the Department of Energy. Phase one of the project developed a 10-kW gross output engine. However, an electric vehicle will require between 30 and 50 kW to perform as well as today's gas-powered automobiles. To reach the wattage goal, the researchers are designing an electrochemical engine that runs on stacks of proton-exchange membrane fuel cells and methanol. An onboard fuel processor converts methanol into hydrogen and carbon dioxide. The fuel cell, in turn, electrochemically combines the hydrogen with oxygen from outside air to produce direct current. The resulting electricity powers the traction motors that turn the car's wheels. The first-generation 30-kW fuel cell stack will be about half the size of a microwave oven. FAX Kathy DeLucas at (505) 667-3559.

Natural fiber/urethane sandwich creates 'greener' headliners

Cambridge Industries, Madison Heights, MI, will introduce to North America a technology said to produce more cost-effective, lighter headliners than glass-reinforced counterparts. The system uses natural fibers instead of glass in a urethane-foam sandwich design. In addition, the Empeflex material should be more user friendly than glass, since it employs such natural fibers as jute, flax, or hemp. The fibers are sandwiched between the urethane foam layers to add strength to the headliners. Cambridge will open a prototype facility in Canandaigua, NY, to produce 250 headliners per day beginning this fall. The component will be marketed through C.E. Automotive Trim Systems, a joint venture between Cambridge and EMPE Werke of Geretsried, Germany. Buyers of 1996 Opel Astra, Corsa, Omega, and BMW 3-series autos will find the "green" material used on door and quarter panels. FAX (810) 616-0500.

Finally, a cure for those drop-off transportation blues

You're in a queue in your car waiting to drop your child off at school, the line holding up traffic in the street gets longer, tempers are getting shorter, and safety takes a backseat as everybody tries to get to the drop-off point. Lily Elefteriadou, an assistant professor of civil engineering at Penn State's Pennsylvania Transportation Institute, theorized that simulation software could allow transportation planners to rearrange a drop-off site and traffic patterns on the computer until they find the best solution. She then demonstrated that the process can be quick, efficient, and economical using the General Purpose Simulation System, the same software package industry uses to simulate the queuing of manufactured products. Using the simulation, Elefteriadou found that traffic congestion could be practically eliminated at one school experiencing drop-off problems if parents avoid the morning's 7:19 to 7:32 peak arrival time. Constructing a right-turn bay for three to four vehicles just before the driveway entrance would take care of the remaining congestion. Elefteriadou incorporates the technique in her graduate Traffic Operations and Simulation class. FAX (814) 863-4749.

'Designer' asphalt process promises longer-lasting roads

Atechnology invented at the University of Toronto uses elastomers and plastomers to modify asphalt. The process creates a physical and chemical structure throughout the asphalt "that results in both high- and low-temperature performance improvements," says Bruce Harbinson, president of Polyphalt, Inc., the Toronto-based company that licenses the technology. The process's versatility, Harbinson adds, allows asphalt materials to be designed to meet precise criteria for high-performance and extreme climatic or service conditions. The technology also offers environmental advantages, since it incorporates recycled plastics and rubber from used tires. The crystalline structure of the plastic reinforces and stiffens the binder to prevent rutting, while the plastic and rubber dispersion inhibits crack propagation and improves low-temperature properties. A natural anti-stripping agent improves adhesion between the asphalt and the aggregate to reduce moisture penetration and freeze-thaw damage. FAX (416) 978-8605.

Software continues its thrust into the automotive design world

Shorter design cycles and increased emphasis on cost-cutting and quality have motivated automakers to rely more heavily on computer-aided design. Two recent examples: the United Kingdom's Rover Group and Japan's Honda Engineering Co. Computervision Corp., Bedford, MA, has entered into a $9 million, three-year services contract with Rover to accelerate and spread the adoption of Computervision technology throughout the company and its suppliers. Rover is believed to be the first car maker to fully embrace Computervision's Electronic Product Definition strategy, an approach that enables a complete vehicle and associated manufacturing infrastruture to be defined as a "virtual" digital computer model. Meanwhile, Structural Dynamics Research Corp. (SDRC), Milford, OH, and Honda Engineering have joined forces to apply I-DEAS Master Series™ software to advanced car-body tooling. The cooperative effort will enable SDRC to enhance I-DEAS 3D variational design engineering technologies to further improve Honda's product quality and time-to-market capabilities. FAX Computervision at (617) 275-2670, or SDRC at (513) 576-2135.