Abstract |
Methods were developed of generating, collecting, and analyzing particulates in automotive engine exhaust by a means sufficiently accurate and reproducible to allow determination of the effects of fuel additives on exhaust particulate size, concentration, and composition. An air dilution chamber was designed which allows for cooling, dilution, and mixing so that representative particulate samples can be obtained at a sampling station which is essentially equivalent to 8 - 10 feet downstream of the end of the exhaust pipe on a vehicle at highway speeds. A 1970 Chevrolet 350 CID engine of 9.0:1 compression ratio with a standard exhaust system attached, was loaded by means of an engine dynamometer. Special analysis techniques were developed for the analysis and characterization of exhaust particulates. The data suggest a very significant effect of fuel additives, primarily tetraethyl lead, on exhaust particulate size, concentration and composition. Significant differences are observed with minor changes in other fuel additives. (Author) |