Spatial and temporal independent component analysis of flame dynamics in diesel engine

This paper reports on the application of both spatial and temporal independent component analysis (sICA and tICA) to luminosity images collected during experiments performed on an optically accessible Diesel engine. The two approaches decompose the data into independent spatial and temporal components, respectively. In both cases two leading independent components (IC) and their corresponding coefficients are determined using an optimization algorithm, and analyzed. As already reported in earlier works, when two components are extracted from a single cycle of a Diesel engine, their clear correlation with different combustion modes can be observed. Namely, the combustion of the injected fuel along the jets axes, and the subsequent combustion near the bowl walls. On the other hand, application of tICA, producing temporal independent signals and coefficients in the form of a spatial map, shows strong correlation of the integral luminosity with the determined ICs.