The relationship between cyclic variations in spark-ignition engines and the small structure of turbulence

✍ Scribed by P.G. Hill; A. Kapil

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 703 KB
• Volume: 78
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(89)90128-4

✦ Synopsis

The hypothesis that cyclic variations in combustion in spark-ignition engines originate in the small-scale structure of turbulence has been further examined in the light of experimental data from a single-cylinder research engine. The data cover a wide range of engine speed and equivalence ratio. The effects of spark electrode geometry, spark gap, chamber geometry, and throttling have also been examined. The general conclusion is that the standard deviation in burning time, deduced for the smallest size flame kernels, is estimated within experimental uncertainty by a parameter k/4ut, in which X is the Taylor microscale and ut is the laminar burning velocity of the unburned mixture.

The experimental results are thus consistent with the interaction of an effectively point-source ignition with the turbulence structure model of Tennekes, and with the idea that rapid burning takes place in the "vortex tube" regions of high dissipation.