Southwest Research Institute^® (SwRI^®) News

SwRI launches consortium to study catalytic converter design validation and durability

Data could improve current vibration and design validation tests

San Antonio -- February 24, 1997 -- Engineers at Southwest Research Institute^® (SwRI^®)   are launching a cooperative program to study the vibration, temperature, and exhaust gas acoustic pressure environments of modern automotive catalytic converter systems.

"Catalytic converter vibration and design validation tests date back to the 1970s, when carbureted engines with underbody catalytic converters dominated the passenger car markets," says Program Manager Martin J. Heimrich, senior research engineer in the SwRI Emissions Research Department. "Because manufacturers are moving catalytic converters closer to the engine, the converters are now exposed to higher exhaust gas temperatures and greater vibrational and exhaust gas pulsation forces. These changes make the older test procedures inappropriate for today's catalytic converters."

A growing number of exhaust system designs incorporate catalytic converters that are "close-coupled" to the exhaust manifold. This location is preferred because, after the startup of a cold engine, a close-coupled catalyst can typically reach an efficient operating temperature more quickly than a catalyst positioned in an underbody location. This substantially reduces the cold-start emissions.

Based on the data generated during the program, SwRI will recommend general categories of scientifically based catalytic converter physical durability tests. The program will focus on the close-coupled converter because it is likely to experience the highest temperatures and greatest engine-induced vibrational and acoustic forces. Physical measurements of the catalytic converter environment will be made on as many as six vehicles, expected to vary in engine type and cylinder head design, catalytic converter system design, transmission type, and intended service application. The parameters to be measured and analyzed include catalytic converter temperature, vibration, and back pressure.

This cooperative research study addresses precompetitive physical durability testing concerns of catalytic converter designers, catalyst companies, and vehicle manufacturers. Participants will be provided with information needed to improve the design and testing of automotive catalytic converters. Consortium members will be invited to attend regular progress meetings, and all data will be proprietary to the participants. A project advisory committee, made up of representatives from each member organization, will provide guidance. The cost to participate in the one-year catalytic converter cooperative research program is $45,000. Contact Heimrich at (210) 522-3022 for more information.

For more information about the catalytic converter cooperative, contact Maria Martinez, Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510, Phone (210) 522-3305, Fax (210) 522-3547.

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