SOOT VOLUME FRACTION IMAGING

A technique is described for the determination of soot volume fraction s 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 allo ws the study of time-dependent phe nomena and the investigation of spatial and temporal correlations. A t elecentric imaging configuration is employed to provide depth invarian t magnification and to permit the specification of the collection angl e far scattered light. A method is also employed to suppress undesirab le coherent imaging effects. A discussion of the tomographic inversion process is also provided, including the results obtained from numeric al simulations. (C) 1997 Optical Society of America.