REFRACTIVE-INDEX MATCHING AND MARKING METHODS FOR HIGHLY CONCENTRATEDSOLID-LIQUID FLOWS

Two index-matched systems of solid particles in liquid have been devel oped to enable the study of velocity and concentration distributions i n the highly concentrated solid-liquid hows. The mixtures have excelle nt optical transparency up to depths exceeding: 80 mm at concentration s up to 50% solids by volume. Highly visible marker particles with nea rly the same mechanical properties as the index-matched particles are formed by metal plating or substitution. Good quality images of marker particles are obtained in both stationary and moving two-phase mixtur es, and permit accurate tracking of the individual markers.