Experimental Study of Ignition and Combustion Characteristics of a Diesel Pilot Spray in a Lean Premixed Methane/Air Charge using a Rapid Compression Expansion Machine Swiss Federal Institute of Technology

Format:

Conference/Event

Author/Creator:

Schlatter, Schlatter, author.

Contributor:

Boulouchos, Konstantinos

Schneider, Bruno

Wright, Yuri

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

The behavior of spray auto-ignition and combustion of a dieselspray in a lean premixed methane/air charge was investigated. Arapid compression expansion machine with a free-floating piston wasemployed to reach engine-relevant conditions at start of injectionof the micro diesel pilot. The methane content in the lean ambientgas mixture was varied by injecting different amounts of methanedirectly into the combustion chamber, the ambient equivalence ratiofor the methane content ranged from 0.0 (pure air) to 0.65. Twodifferent nozzle tips with three and six orifices were employed.The amount of pilot fuel injected ranged between 0.8 and 1.8percent of the total energy in the combustion chamber. Filtered OHchemiluminescence images of the combustion were taken with aUV-intensified high-speed camera through the optical access in thepiston. Filtered photomultiplier signals of the total emitted lightfor OH, CH and C₂ radicals as well as the pressure signal weresimultaneously recorded and the effect of methane content andnozzle geometry on ignition locations, ignition timing andcombustion behavior was analyzed.It was seen, that higher values of the equivalence ratio promotepropagation of the premixed flame as expected, but delay theautoignition of the pilot spray considerably. Furthermore, it wasobserved that even for very low equivalence ratios, substantialheat release occurs around the spray in the premixed charge,although no flame propagation in the classic sense can besustained. For the whole range of equivalence ratios, the use ofthe six-hole injector was seen to considerably assist conversion ofthe entire premixed charge

Notes:

Vendor supplied data

Publisher Number:

2012-01-0825

Access Restriction:

Restricted for use by site license