Combustion Behavior and Fuel Economy of Modern Heavy-Duty Diesel Engine Using JP8 and Alternative Fuels

Principal Investigator: Angela Violi, University of Michigan,
Faculty: Jason Martz, University of Michigan
Student: Doohyun Kim, University of Michigan
Government: Peter Schihl, Eric Sattler, U.S. Army TARDEC
Industry: Peter Attema, Detroit Diesel/Daimler

PES_molJP-8 has replaced diesel fuel (DF-2) as the single battlefield fuel used by the military in the diesel engines of nearly all tactical ground vehicles. However, the specifications of JP-8 are much looser than DF-2, resulting in wide variations in composition. This is an important issue when it comes to designing an engine to handle such fuel composition variations in order to ensure reliable operability in all theaters. Previous studies lack detailed fundamental insight into the underlying physical phenomena of the combustion process.

Using JP-8 in diesel engines offers significant benefits, such as less fouling of the fuel injection system and potentially lower soot emissions, and thus an attenuated visual signature. However, JP-8 has lower volumetric calorific value than diesel, which translates to higher fuel consumption and shorter range. In addition, the cetane number (CN) of JP-8 is highly variable. JP-8 ignition delays increase when the CN of JP-8 is lower than that of DF-2 , potentially leading to misfire and a compromise in the ability of an engine to start reliably. Also the high volatility and low CN of JP-8 translates to more vigorous combustion, resulting in knocking and potential damage to the piston.

The overarching goals of the project can be summarized as follows:

  • Develop the framework for the CFD modeling of spray and combustion, using state-of-the-art chemical kinetics for JP-8 and JP-8 alternative fuels.
  • Develop new chemical kinetic schemes and surrogate composition(s) in order to better simulate combustion with JP-8 and JP-8 alternative fuels of varying CN. Develop a reduced kinetic mechanism suitable for CFD application.
  • Perform engine experiments to further assess the impact of JP-8 and JP-8 alternative fuel variations, including CN.
  • Understand the impact of JP-8’s physical properties and chemical reactivity on the combustion, performance and emission characteristics of compression ignition engines through modeling and engine experiments.


  • Doohyun Kim, Jason Martz, Angela Violi, "A surrogate for emulating the physical and chemical properties of jet fuel", The 8th U.S. National Combustion Meeting, Paper # 070IC-0269
  • Doohyun Kim, Jason Martz, Angela Violi, "A surrogate for emulating the physical and chemical properties of conventional jet fuel", Combustion and Flame 161 (2014) 1489~1498