Search Results

Recent developments in measurement techniques enabled researchers to measure ultra-fine particulates of nano-scale range and provided more evidence that the smaller particulates typically emitted from gasoline engines may have more severe impacts on human respiratory system than the bigger particulates from diesel engines. The knowledge of the characteristics of particulates from gasoline engines, especially, the effect of fuel borne additives is sparse. This work presents the findings from a study into the effect of aftermarket additives on nano-scale particulates. Four commercially available fuel borne additives used in gasoline engines mainly by private vehicle owners in the United Kingdom were selected for this study. The combustion and emission performance of the additive fuels were compared against that of commercially available gasoline fuel using a 4-stroke, throttle body injected gasoline engine.

This work attempted to correlate the ultra fine particulate count to the flame propagation time, in-cylinder peak pressure, and in-cylinder ageing time (the time the particulates stay inside the cylinder) of a throttle body gasoline injected engine. The engine was tested at different loads and speeds ranging from 20 Nm to 100 Nm and 2000 to 3400 rpm respectively. A fast particle spectrometer, a mass spectrometer, and an in-cylinder pressure measurement system were used to characterize the particulate emission. This work identified the correlation between the nucleation of particulates and rate of burning, the particulate count for particles size greater than 200 nm and the in-cylinder ageing time. It identified that an increase in engine load at constant speed increased the particle number density of the 10 nm diameter particles; the effect was less significant on the particles of diameter greater than 50 nm and almost absent on particles of diameter greater than 200 nm.

The present work evaluated the performance of a EURO-IV vehicle for real-world driving in Mexico City. This work also attempted to identify if it was possible to reduce green house gas emission and fuel consumption for real-world driving in Mexico City by using vehicle technology available in EURO-IV certified vehicles. It used three different drive cycles representing typical driving conditions in North, South and Central zones of Mexico City. These drive cycles were developed using a single instrumented-experimental vehicle and the data collected from 200 trips over a year covering peak and off-peak driving conditions. This work used a vehicle-powertrain model of a EURO-IV vehicle, which was validated by the authors using experimental data for four other drive cycles that represented typical driving conditions in the United Kingdom.