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CLEERS Teleconference: Prof. Scott Sanders, University of Wisconsin
July 22 @ 11:00 - 12:00 EDT
Laser-based Ammonia Imaging and Prospects for other Applications of Absorption Spectroscopy in Aftertreatment Systems
Prof. Scott Sanders
University of Wisconsin
First, this talk will describe ammonia imaging experiments performed at Cummins Emission Solutions. In that work, we used a 10.4 um laser to image ammonia concentration in a diesel aftertreatment system. Optical access through a 33-cm-diameter duct was facilitated by cutting 3 slits in the duct and sealing them with polyimide film. The laser was mounted on a translation-rotation stage providing 33 cm of translation and 180 degrees of rotation, so that the laser beam could be directed through the duct at arbitrary positions and angles. Using 2130 unique position-angle combinations, recorded sequentially over a 1.25-hour duration, we were able to compute a 100-image video of the ammonia concentration field representing 0.5 seconds of real time. The video processing assumes the evolution of ammonia in the measurement plane is repeatable with a period of 1 Hz set by the DEF doser. The results reveal the uniformity of ammonia and how the ammonia concentration field varies over time. Second, this talk will briefly describe some future opportunities for absorption spectroscopy in diesel aftertreatment systems.
Prof. Sanders received his Ph.D. from Stanford University in 2001, and has been on faculty at the University of Wisconsin since. His group develops optical instrumentation and sensors that help solve critical problems primarily in the combustion and energy areas but also in diverse areas including manufacturing and medicine. He is best known for developing and applying swept-wavelength lasers to measure gas properties at high repetition rates (e.g. 1 MHz) using absorption spectroscopy.