Identification and imaging of OH (nu'' = O) and O(2) (nu'' = 6 or 7) in an automobile spark-ignition engine using a tunable KrF excimer laser.
Planar laser-induced predissociative fluorescence is applied to image state-specific densities of OH and hot O(2) inside an internal-combustion car engine. Improved instrumentation is described. It includes better imaging optics and a spectrometer that permits desired molecular quantum states to be selected and identified in real time. The OH (nu'' = 0) images are cleanly separated from the isooctane fuel and they display a thin superequilibrium region at the flame front. In contrast, vibrationally excited O(2) (nu'' = 6 or nu'' = 7) is uniformly distributed behind the front. Uneven and broken flame fronts are commonly observed.
Andresen
P
P
Schlüter
H
H
Wolff
D
D
Voges
H
H
Koch
A
A
Hentschel
W
W
Oppermann
W
W
Rothe
E
E