High concentration effects of transmission fluctuation spectrometry with temporal correlation

Abstract

Transmission fluctuation spectrometry (TFS) with temporal or spatial correlation is a recently-developed method for real-time, online/inline particle analysis in two-phase flows, whereby the particle size distribution (PSD) and particle concentration can be measured simultaneously. On the basis of a layer model and the assumption of geometrical ray propagation, an analytical expression of the transmission fluctuation spectrum can be obtained. It is found that the measurement matches the theory very well as long as the particle concentration is low enough. However, as the particle concentration increases, the measured transmission fluctuation spectrum deviates gradually from the theory, which is a result from the high concentration effects. The high concentration effects include those from particle overlapping and the monolayer structure. In this presentation, the high concentration effects are studied with numerical simulation. As a result, the empirical expressions for the correction of the high concentration effects are obtained.