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This paper presents experimental results of studies investigating the effect of nitric oxide (NO) on the autoignition chemistry of a primary reference fuel blend with an octane rating of 87 in a motored engine. The experiments were conducted over a range of operating conditions in a single cylinder research engine at compression ratios of 5.2 and 8.2. The inlet manifold was heated and supercharged to pre-stress the fuel-air mixture in order to produce in-cylinder pressure and temperature histories similar to practical engines. The exhaust gas carbon monoxide concentration was monitored and used as a measure of overall reactivity. In-cylinder pressure histories were also recorded and processed to calculate in-cylinder temperature histories. Results showed that at low manifold temperatures, below that necessary to produce negative temperature coefficient behavior, up to 100 ppm of NO promoted reactivity, whereas higher concentrations retarded the reactivity.

Ceramic monolith particulate filters were evaluated for reduction of odor and irritant species in diesel exhaust. Three types of diesel particulate filters (DPF's) were tested: high efficiency catalyzed and uncatalyzed, and mid efficiency uncatalyzed. Testing was done with a single cylinder CFR diesel test engine run under steady-state conditions at low, mid and high equivalence ratios. Exhaust was sampled immediately upstream and downstream of the DPF's and analyzed on liquid chromatographs. The odorant species analyzed were oxygenated hydrocarbons (oxygenates), measured using the DOAS methodology. The irritant species analyzed were Cl to C5 aldehydes, measured using a DNPH reagent method. The high efficiency catalyzed DPF reduced exhaust oxygenate concentrations about 30% at low and mid equivalence ratios, which was the only substantial oxygenate reduction seen.

Because diesel engines operate on an efficient thermodynamic cycle at a low economic cost, their particulate pollution has been tolerated. However, the Environmental Protection Agency is now setting more stringent particulate emission standards to be met by all diesel-powered vehicles. One candidate system to meet the new EPA requirements is a continuously regenerative porous metal trap oxidizer device. A test program was initiated to evaluate the design and performance of this diesel particulate filter (DPF) on a single-cylinder diesel engine. This DPF is comprised of a rotating porous metal filter element driven by a variable speed electric motor, a heater element for filter regeneration, a nozzle for controlling the particulate deposit pattern on the filter element, a scraping device to insure proper filter regeneration, and a stainless steel housing. A 20-micrometer powder metal element and a 21-micrometer fiber metal element were tested.