Technical Paper
Laser-Induced Fluorescence Imaging of NO in a Port-Fuel-Injected Stratified-Charge SI Engine-Correlations Between NO Formation Region and Stratified Fuel Distribution
1998-05-04
981430
NO laser-induced fluorescence (LIF) imaging and quantitative fuel distribution measurements in aport-fuel-injected 4-valve stratified-charge single-cylinder SI engine have been conducted using a tunable KrF excimer laser. The correlations between NO formation region and fuel distribution have been investigated for the horizontal stratification realized by fuel (iso-octane) injection in only one intake port. The NO LIF intensity is proportional to the exhaust NOx emissions. The strong NO LIF intensity region in expansion stroke corresponds to the location of the region with equivalence ratio (ϕ) between 0.8 and 1.1 in the stratified fuel distributions at spark timing. The exhaust NOx concentration is proportional to the area of region with ϕ =0.8 - 1.1.
