JP-8 military aviation fuel is a kerosene-type jet fuel that is equivalent to civil JET A-l fuel with the exception ofits 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...
JP-8 military aviation fuel is a kerosene-type jet fuel that is equivalent to civil JET A-l fuel with the exception ofits 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 m 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-ho1e solenoid-driven injector installed on the common-rail system. The injection rate was measured via the Bosch tube method. For better understanding of spray development, macroscopic images were obtained using a charge-coupled device (CCD) camera in a constant volume vessel pressuhzed by inert gas. Experiments were carried out at various injection pressures, injection quantities, and injection timings for both JP-8 and diesel. The injection rate results indicate that, due to its lower viscosity, the actual injection of JP-8 starts and finishes earlier than that of diesel. The spray tip penetration of JP-8 was shorter than that of diesel, while the spray angle of JP-8 was wider than that of diesel. These characteristics result from the lower distillation temperature, viscosity, density, and latent heat of JP-8, and they imply that the vaporization of JP-8 is superior to that of diesel. The lower cetane number of JP-8 results in an extension of the ignition delay period, and an increase in the portion of premixed combustion. The indicated mean effective pressure (IMEP) using JP-8 is lower than that of diesel. JP-8 produced less soot under all conditions possibly through better mixture preparation due to the higher volatility and longer ignition delay of JP-8. This result was confirmed by the combustion images taken with a high-speed camera. Compared to diesel combustion, JP-8 can simultaneously reduce both nitrogen oxide (NO_(x)) and soot when the engine operates at 1200 rpm with a fuel injection pressure of 140 MPa and an injection quantity suitable for low load conditions. In terms of combustion, JP-8 was found compatible with the common-rail diesel engine.
JP-8 military aviation fuel is a kerosene-type jet fuel that is equivalent to civil JET A-l fuel with the exception ofits 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 m 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-ho1e solenoid-driven injector installed on the common-rail system. The injection rate was measured via the Bosch tube method. For better understanding of spray development, macroscopic images were obtained using a charge-coupled device (CCD) camera in a constant volume vessel pressuhzed by inert gas. Experiments were carried out at various injection pressures, injection quantities, and injection timings for both JP-8 and diesel. The injection rate results indicate that, due to its lower viscosity, the actual injection of JP-8 starts and finishes earlier than that of diesel. The spray tip penetration of JP-8 was shorter than that of diesel, while the spray angle of JP-8 was wider than that of diesel. These characteristics result from the lower distillation temperature, viscosity, density, and latent heat of JP-8, and they imply that the vaporization of JP-8 is superior to that of diesel. The lower cetane number of JP-8 results in an extension of the ignition delay period, and an increase in the portion of premixed combustion. The indicated mean effective pressure (IMEP) using JP-8 is lower than that of diesel. JP-8 produced less soot under all conditions possibly through better mixture preparation due to the higher volatility and longer ignition delay of JP-8. This result was confirmed by the combustion images taken with a high-speed camera. Compared to diesel combustion, JP-8 can simultaneously reduce both nitrogen oxide (NO_(x)) and soot when the engine operates at 1200 rpm with a fuel injection pressure of 140 MPa and an injection quantity suitable for low load conditions. In terms of combustion, JP-8 was found compatible with the common-rail diesel engine.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.