Instability of Uniform Concentration Conditions in Suspensions under Shear

Abstract

IN an earlier paper by one of us¹ it was shown theoretically that in a suspension under shear the action associated with an isolated suspended particle will be a minimum when the particle follows the streamline characterized by minimum velocity gradient. The principle of least action requires that a particle initially situated at a point in a velocity field at which the gradient is not a minimum should move with a component of motion normal to the direction of flow towards regions of lower velocity gradient. In a subsequent paper² direct evidence of this component was adduced from a study of the motion of streams of suspended particles.