Modern Diesel Particulate Matter Measurements and the Application of Lessons Learned to 2007 Levels and Beyond 2005-01-0194

Experimental tests were conducted to determine the sensitivity of Diesel particulate matter (PM) at a given engine operating condition using a single cylinder research engine at the University of Wisconsin Engine Research Center. Utilizing a full dilution tunnel with a second stage partial dilution tunnel, the PM emissions were characterized. Physical properties were measured with a variety of instruments including a Scanning Mobility Particle Sizer (SMPS), Tapered Element Oscillating Microbalance (TEOM) as well as traditional filter-based gravimetric measurements. Chemical composition was determined through the use of the Thermal/Optical Transmittance (TOT) Method, Ion Chromatography (IC) and Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP/OES).

Particulate mass emissions were shown to be on the order of 0.05 g/bhp-hr for the light load engine operating condition selected. Although pertaining perhaps to this particular fuel system and engine configuration, a brief discussion of the sensitivity to key engine parameters such as boost pressure, intake manifold air temperature and injection timing is discussed.

More importantly, however is the global relevance in the measurement of Diesel particulate matter at these scales. With future legislation regulating emissions at such low levels, the measurement capability needs to be fully understood. This paper discusses measurement capability for each of the key variables in determining the engine out emissions, error propagation from these measurements to the calculated brake specific emissions, as well as sensitivity to each revealing the critical measurements required in accurately characterizing Diesel particulate matter at 2007 levels and beyond.