PHYSICAL SIZE DISTRIBUTION CHARACTERIZATION OF DIESEL PARTICULATE MATTER AND THE STUDY OF THE COAGULATION PROCESS
Diesel particulate matter in both the diluted and undiluted state is subject to the processes of coagulation, condensation or evaporation, and nucleation which causes continuous changes in its physical characteristics. The Electrical Aerosol Analyzer (EAA) is used to measure the diesel particle size distribution in the Michigan Technological University dilution tunnel for a naturally aspirated direct-injection diesel engine operated on the EPA 13 mode cycle. The design and development of accurate and repeatable sampling methods using the EAA are presented. These methods involve both steady-state tunnel and bag measurements. The data indicate a bimodal nature within the 0.001 to 1 millimicron range. The first mode termed the "embryonic mode" has a saddle point between 0.005 to 0.015 millimicron and the second mode termed the "aggregation mode" lies between .08 to .15 millimicron for the number distribution. The particle concentration decreases with time and the resulting size distribution function approaches an asymptotic steady-state solution indicating the self-preserving nature of particulate size distributions. Coagulation constants have been calculated for the diesel particles and are compared to theoretical values in the literature.
- For Meeting held September 11-14, 1978.
Warrendale, PA USA 15096
- Khatri, N J
- JOHNSON, J H
- Publication Date: 1978
- Features: References;
- Pagination: 27 p.
- TRT Terms: Air pollution; Air pollution sources; Diesel engine exhaust gases; Measuring instruments
- Subject Areas: Environment; Railroads;
- Accession Number: 00190350
- Record Type: Publication
- Source Agency: Engineering Index
- Report/Paper Numbers: SAE 780788 Preprint
- Files: TRIS
- Created Date: May 26 1979 12:00AM