EXPERIMENTAL INVESTIGATION OF THE PERFORMANCE AND EXHAUST EMISSIONS OF A SWIRL CHAMBER DIESEL-ENGINE USING JP-8 AVIATION FUEL

An experimental study is conducted to evaluate the use of JP-8 aviatio n fuel as a full substitute for diesel fuel in a Ricardo E-6 high-spee d naturally-aspirated four-stroke experimental engine having a swirl c ombustion chamber. The study covers a wide range of engine load and sp eed operating conditions, comprising measurements of cylinder pressure diagrams, high-pressure fuel pipe pressures, exhaust gas temperatures , fuel consumptions, exhaust smokiness and exhaust gas emissions (nitr ogen oxides, unburned hydrocarbons and carbon monoxide). Processing of the measurements provides important performance parameters such as ma ximum combustion pressure, dynamic injection timing, ignition delay, c ombustion irregularity and knocking tendency. The differences in the m easured performance and exhaust emission parameters are determined for engine operation with JP-8 fuel, against baseline engine operation us ing diesel fuel. The study shows that the exhaust emission levels are not much different for operation with the two fuels. On the contrary, operation with JP-8 fuel increases combustion pressures, combustion in tensity and irregularity. This is caused mainly by high pressure fluct uations present in the fuel injection system due to the different phys ical properties of JP-8 fuel (compared to diesel fuel), which totally change the injection characteristics. Retardation of the static inject ion timing is one means of improving this situation, while using the s ame fuel injection equipment. (C) 1997 by John Wiley & Sons, Ltd.