Accession Number : ADA622168


Title :   Fundamental Investigation of Jet Fuel Spray and Ignition Process in an Optically Accessible Piston Engine


Descriptive Note : Final rept. 17 Oct 2011-16 Oct 2014


Corporate Author : WISCONSIN UNIV MADISON


Personal Author(s) : Rothamer, David ; Neal, Nicholas


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA622168


Report Date : 16 Jan 2015


Pagination or Media Count : 48


Abstract : Effects of transient rate-of-injection (ROI) fuel sprays on jet development and combustion were measured in a compression-ignition direct injection optical engine. Jet penetration, liquid length, jet dispersion angle, liftoff length, and engine cylinder pressure data were simultaneously acquired over a range of engine operating conditions relevant to the design of Army engines. Tests were performed using #2 diesel fuel, jet fuel (JP8), and a hydroprocessed renewable jet fuel (HRJ). Ambient thermodynamic conditions and fuel injection parameters had similar effects on combustion and jet performance in the optical engine as in previous results from constant volume chambers. The ramp-on transient from the opening of the fuel injector caused the scaling of jet parameters with time during the transient ROI to be modified from relationships expected from the literature. Similarities were seen in a comparison between the jet velocity, the derivative of the ROI and the derivative of a curve fit created to model the data taken. In the long-time limit, these injections were seen to return to their quasisteady forms, with the changes in jet parameters occurring during the initial opening of the injector. The results show the need to resolve the initial transient injection process in small bore diesel engines.


Descriptors :   *FUEL INJECTION , *JET ENGINE FUELS , *PISTON ENGINES , CHAMBERS , COMBUSTION , COMPRESSION IGNITION ENGINES , CURVE FITTING , CYLINDRICAL BODIES , DIESEL ENGINES , DISPERSING , FUEL SPRAYS , IGNITION , OPTICAL PROPERTIES , SCALING FACTOR , THERMODYNAMICS , TRANSIENTS , VELOCITY


Subject Categories : Thermodynamics
      Combustion and Ignition
      Fuels
      Reciprocating and Rotating Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE