Advances in quasi-elastic scattering of light with emphasis on simultaneous measurements of velocities and sizes of particles embedded in flows

Advances in quasi-elastic scattering of light are studied, and the theoretical analysis includes: (1) a generalized Lorenz-Mie theory (GLMT), describing the quasi-elastic linear scattering of light; (2) a computer program using the Lentz algorithm to compute ratios of Bessel functions; (3) a comparative analysis of the GLMT and geometrical optics; and (4) a discussion of new monotonic relationships between scattered powers and the sizes of scatter centers. The theoretical results are applied to the experimental study which attempts to measure simultaneously the diameter and velocity of individual particles embedded in laminar and turbulent two-phase flows, illuminated by a laser beam. Results show a satisfactory agreement with the theoretical predictions, and it is concluded that simultaneous velocimetry of single particles can be achieved by superimposing on the sizing probe a classical LDV control volume.