PHYSICAL MATHEMATICS SEMINAR

TOPIC:		DYNAMICS AND STRUCTURE IN A QUASI-2D 
		NON-BROWNIAN SUSPENSION

SPEAKER:	PROFESSOR FLORENCE ROUYER
		Department of Physics
		University of Massachusetts, Amherst


ABSTRACT:

Non-brownian suspensions exhibit density and velocity fluctuations.  We
have performed experiments on a quasi-2D counter-flow stabilized
suspension of 2000 spherical particles, namely a liquid-solid fluidized
bed in a Hele-Shaw cell.  The hydrodynamic-interaction-controlled random
walk of spheres is anisotropic : a vertical hyperdiffusion opposes to a
gaussian behavior along the horizontal direction.  This hyperdiffusion is
related to the microstructure of the suspension which is far from being
random.  It happens that the relation between velocity and concentration
fluctuations in a sub-volume can be deduced from a balance between
buoyancy and friction forces.

DATE:		TUESDAY, NOVEMBER 2, 1999

TIME:		2:30 PM

LOCATION:	Building 2, Room 338

Refreshments will be served at 3:30 PM in Building 2, Room 349


					Massachusetts Institute of Technology
					Department of Mathematics
					Cambridge, MA  02139