Soot volume fraction imaging

A technique is described for the determination of soot volume fractions by laser light extinction measurements. This technique differs from previously reported pointwise methods in that a two-dimensional array (i.e., image) of data is acquired simultaneously. In this fashion the net data rate is increased and allows the study of time-dependent phenomena and the investigation of spatial and temporal correlations. A telecentric imaging configuration is employed to provide depth invariant magnification and to permit the specification of the collection angle for scattered light. A method is also employed to suppress undesirable coherent imaging effects. A discussion of the tomographic inversion process is also provided, including the results obtained from numerical simulations.