Combustion pollution control strategies

Catalytic converters were first installed in U.S. cars in 1976.20 21 They were passive devices in that they were simply placed in the exhaust with no communication with the engine or its control strategy. It catalyzed the oxidation of the unburned hydrocarbons (CyHn) and carbon monoxide (CO) emitted during the incomplete combustion of the fuel. In some vehicles excess air was pumped into the exhaust to ensure sufficient oxygen to complete the catalytic oxidation. This resulted in about a 90% reduction of these two pollutants relative to the uncontrolled uncatalyzed vehicle. 

The present work involves detailed measurements of flow, pollutant emissions, and acoustics in model multiple-swirl, partially-premixed flames and combustors. Complementary computations are also planned, combining computational aeroacoustics approaches with combustion modeling. The focus is on how pollutant control and flame stabilization strategies, such as partial premixing and swirl, respectively, influence combustor noise sources and potential instabilities. Also of interest are flow and acoustics associated with diffuser-combustor interactions and the utility of the trapped-vortex combustor design. A better understanding of pollutant and acoustic sources and how to modify them will aid in the control of emissions, noise, and instabilities in modern swirl combustors. 

Tucker and his advisors developed a new strategy for smoke control, focused on the fuel rather than the combustion process. After a severe pollution episode on November 28, 1939, regulations were put in place that allowed only high-grade coal to be burned. Boilers had to be modernized. With these rules strictly enforced, St. Louis by the winter of 1941 could boast of a 72% reduction in visible smoke. Other industrial cities such as Pittsburgh and Cincinnati would follow its lead after the war.5... 

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