Diffusion Waves in a Particulate Suspension – A Model for Blood Sedimentation

date February 27, 1985
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Wednesday, February 27, 1985 12:00 p.m.

A. Bedford
ASE-EM Department
Applied Research Laboratories
The University of Texas at Austin

Although the classical diffusion equation is parabolic, in certain mixture models for the motion of particles in a fluid the equations of motion are hyperbolic and predict a phenomenon that can be called a “diffusion wave.” A description of such a model will be given. It will be shown that including diffusive effects (such as Brownian motion) in the model causes the equations to be hyperbolic and also leads to the prediction that the state of steady sedimentation is stable under small disturbances. Numerical solutions obtained from the model will be compared with cell concentration profiles measured during sedimentation of human whole blood. Recent results on acceleration waves in particulate suspensions will also be described.