We analyze particle segregation in suspensions of rigid particles immersed in Newtonian liquids flowing in plane Couette devices by considering the stability of the system to two-dimensional perturbations in the plane of shear. We obtain the dispersion relation analytically for small wave numbers, finding that when the velocity of the walls is kept constant, the system is always stable and the particle concentration remains uniform. On the other hand, when we keep constant the shear applied at one wall, we predict that a disorder-order transition will occur, provided that an appropriate non-dimensional parameter is larger than 1. This coefficient expresses the ratio between the effects of shear-induced migration and shear-induced diffusion.
The Onset of Particle Segregation in Plane Couette Flows of Concentrated Suspensions
MAURI, ROBERTO;
2002-01-01
Abstract
We analyze particle segregation in suspensions of rigid particles immersed in Newtonian liquids flowing in plane Couette devices by considering the stability of the system to two-dimensional perturbations in the plane of shear. We obtain the dispersion relation analytically for small wave numbers, finding that when the velocity of the walls is kept constant, the system is always stable and the particle concentration remains uniform. On the other hand, when we keep constant the shear applied at one wall, we predict that a disorder-order transition will occur, provided that an appropriate non-dimensional parameter is larger than 1. This coefficient expresses the ratio between the effects of shear-induced migration and shear-induced diffusion.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
