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Influence of air motion variation on the performance of a direct-injection stratified-charge engine

Conference ·
OSTI ID:5013470

Swirl rates and turbulence levels in an optically accessible research engine were varied by changing the orientation of the shrouded intake valve. The air motion within the cylinder was characterized using laser Doppler velocimetry. Measurements of the indicated mean effective pressure are reported as a function of the shroud orientation, equivalence ratio, and ignition timing. Laser shadowgraph photography was used to visualize the interaction of the fuel jet with the swirling flow and the ensuing combustion process. For the case of high-swirl/low turbulence, the flame is seen to remain attached to the spark plug, and its rapid propagation is convection dominated; for low-swirl/high-turbulence conditions, the flame is not attached, and propagation is mainly by turbulent diffusion.

Research Organization:
Sandia National Labs., Albuquerque, NM (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
5013470
Report Number(s):
SAND-79-8756; CONF-801127-1
Country of Publication:
United States
Language:
English