Imaging and Scattering Measurements for Diesel Spray Combustion: Optical Development and Phenomenological Studies

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. The first successful demonstration of picosecond ballistic imaging using a greater-than-10 picosecond-pulse-duration laser in diesel sprays is reported. This technique uses an optical Kerr effect shutter constructed from a CS2 liquid cell and a 15 picosecond pulse at 532 nm. The optical shutter can be adjusted to produce effective imaging pulses between 7 and 16 picoseconds. This technique is used to image the near-orifice region (first 3mm) of diesel sprays from a high-pressure single-hole fuel injector. Ballistic imaging of dodecane ABSTRACTThe first successful demonstration of picosecond ballistic imaging using a greater-than-10 picosecond-pulse-duration laser in diesel sprays is reported. This technique uses an optical Kerr effect shutter constructed from a CS2 liquid cell and a 15 picosecond pulse at 532 nm. The optical shutter can be adjusted to produce effective imaging pulses between 7 and 16 picoseconds. This technique is used to image the near-orifice region (first 3mm) of diesel sprays from a high-pressure single-hole fuel injector. Ballistic imaging of dodecane and methyl oleate sprays are reported. The first known ballistic images of diesel injection at pre-ignition engine-like conditions are reported. Dodecane was injected into air heated to 600°C and pressurized to 20 atm. The resulting ballistic images of the near-orifice region at these diesel-engine-like conditions reveal dramatic shedding of the liquid near the nozzle, an effect which has been predicted, but to our knowledge never before imaged. Several parameters are explored including injection pressure, liquid fuel temperature, air temperature and pressure, and fuel type. Resulting trends are summarized with accompanying images. Finally, the beginings of a new ballistic scattering technique is presented with preliminary results. Names of Post DoctoratesPERCENT_SUPPORTED NAME FTE Equivalent:Total Number: Names of Faculty SupportedNational Academy Member PERCENT_SUPPORTED NAME Terry Parker 0.05 Jason Porter 0.05 0.10 FTE Equivalent: 2 Total Number: Names of Under Graduate students supportedPERCENT_SUPPORTED NAME FTE Equivalent:Total Number:The number of undergraduates funded by this agreement who graduated during this period with a degree in science, mathematics, engineering, or technology fields:The number of undergraduates funded by your agreement who graduated during this period and will continue to pursue a graduate or Ph.D. degree in science, mathematics, engineering, or technology fields:Number of graduating undergraduates who achieved a 3.5 GPA to 4.0 (4.0 max scale): Number of graduating undergraduates funded by a DoD funded Center of Excellence grant for Education, Research and Engineering:The number of undergraduates funded by your agreement who...