An experimental approach to the study of the sedimentation of dispersed particles in a centrifugal field

Summary  On the basis of an especially developed centrifuge, a PC-controlled separation analyser has been assembled for the continuous registration of particles' sedimentation process in a fluid, caused by centrifugal acceleration. The system enables the parallel investigation of up to eight samples. During the centrifugation, the radial and temporal variation of light transmission through the samples is registered by means of a CCD line detector. Experiments were carried out with the separation analyser on manipulated rigid and sphered red blood cells for the verification of an established one-dimensional mixture fluid model. In particular, the influence of particle volume concentration as well as of the angular velocity on the sedimentation process was investigated. Justification could be furnished for the one-dimensional model based on the theory of kinematic waves and shocks. In addition, an algorithm has been developed for the experimental determination of the suspension's effective or apparent viscosity. Received 20 March 2001; accepted for publication 23 August 2001 RID=" ID=" This work is an abridged version of a part of the first author's PhD thesis. The study was supported in part by the German Federal Ministry of Education and Research (project 03 TOU 2063) and the foundation Deutsche Forschungsgemeinschaft (project Le 734/1–2).