Spray and combustion characteristics of diesel and JP-8 in a heavy-duty diesel engine equipped with common-rail fuel injection system

Abstract

JP-8 military aviation fuel is a kerosene-type jet fuel that is equivalent to civil JET A-1 fuel with the exception of its three military additives. Since the late 1980s, JP-8 has been employed as the primary fuel for all aircraft, vehicles, and equipment in the U.S military and north atlantic treaty organization (NATO) armed forces. The considerable battlefield benefits of using one fuel include simplification of logistics and enhancement of interoperability. This idea is known to as the single fuel concept. The U.S military and NATO armed forces have researched the impact of using JP-8 in diesel engines to realize the single fuel concept. These engines, which are equipped with conventional fuel injection systems such as a mechanical rotary pump, appeared to operate successfully. However, negative effects, including reduction in torque, poor fuel economy, and a reduction in lubrication have been reported. Previous studies on the cumulative effect on performance and emissions of JP-8 are present in the literature. They provide valuable indications of the overall impact of replacing diesel with JP-8. However, the effects of JP-8 on combustion and spray characteristics in diesel engines have not been fully investigated. In terms of fuel injection system, common rail system has accounted for a great portion of the market share in recent years. Accordingly, the common rail diesel engine has been introduced and developed to suit military requirements. Assessments of JP-8 in common rail direct injection diesel engines are also lacking. The objective of the current study is to provide the fundamental spay characteristics of JP-8 and to evaluate the effect of JP-8 on output performance and emissions in a single cylinder optical diesel engine equipped with a common rail system. JP-8 and diesel were injected through an 8-hole solenoid-driven injector installed on the common-rail system. The injection rate was measured via the Bosch tube method. For better un...