High speed imaging of OH* chemiluminescence and natural luminosity of low temperature diesel spray combustion

The influence of charge stratification on the spectral signature of partially premixed combustion in a light-duty optical engine

“…The spectroscopic measurements provide spectral and temporal information regarding the combustion [8,9,11]. The objective of these measurements is to correlate the chemiluminescence intensities of five different components, including thermal radiation, broadband chemiluminescence, and relatively narrowband OH*, CH* and C 2 * emission, in the PPC combustion regime.…”

“…Chemiluminescence occurs in specific wavelength bands that are characteristic of the emitting molecules. The chemiluminescence yield due to specific molecules varies for different combustion regimes, and this can provide information about the nature of the chemistry involved [9][10][11]. Because chemiluminescence is the direct product of exothermic chemical reactions, it marks the location of the initial combustion reactions, both temporally and spatially [10], although reaction pathways leading to chemiluminescent species are under debate [12].…”

“…Many studies have used optical filters to investigate the combustion behavior and detect different species like OH* and CH* [7,11,16,17]. The obvious advantage of spectral bandpass filters is that they allow spatial distribution mapping; the obvious disadvantage is that one can never exclude spectral interference by other emitters than those for which the filter is intended.…”

Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

“…Details about the combustion chamber can be found in previous publications [27,28]. The injector nozzle used in this study has one orifice, allowing detailed imaging of the flame.…”

“…A comparison was then performed for the current Jet-A results with our previous No. 2 diesel results [16,27,28].…”