Investigation of essential elements of stratified-charge combustion

Technical Report · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6980259

Bracco, F V

Laser Doppler velocimetry has been used to make cycle-resolved velocity and turbulence measurements in a homogeneous-charge, spark-ignition engine. The engine had a ported intake and disc-shaped chamber with a compression ratio of 8 to 1. It was operated at a speed of 1200 rpm and with a TDC swirl number of 4. A stoichiometric propane-air mixture was used, and ignition was near the wall. The velocity measurements were made at three spatial locations at the midpoint of the clearance height. Tests were made to determine whether the presence of the flame affected the accuracy of the velocity measurements. It was found that the ensemble-averaged mean velocity shows a small deviation, and the rms fluctuation intensity is significantly influenced, but the effects appear to be confined to the flame zone. Data rates were sufficiently high in the preflame and postflame regions to determine the velocity history in each cycle (cycle resolved) . The cycle resolved turbulence intensity was found to increase across the flame. The turbulence intensity in the burned gas was found to be homogeneous at the three spatial locations examined and to decay rapidly. There was little or no increase in turbulence intensity ahead of the flame.

• Research Organization: Princeton Univ., NJ (United States). Dept. of Mechanical and Aerospace Engineering
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AS04-86AL33209
• OSTI ID: 6980259
• Report Number(s): DOE/AL/33209-T1; ON: DE93000644
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330101* -- Internal Combustion Engines-- Spark-Ignition
AIR
ALKANES
COMBUSTION CHAMBERS
DOCUMENT TYPES
DOPPLER EFFECT
ENGINES
FLAMES
FLOW VISUALIZATION
FLUIDS
GASES
HEAT ENGINES
HYDROCARBONS
INTERNAL COMBUSTION ENGINES
LASERS
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
PROGRESS REPORT
PROPANE
STRATIFIED CHARGE ENGINES
TURBULENCE
VELOCIMETERS