NON-UNIFORM PARTICLE DISTRIBUTIONS DURING TUBE FLOWS OF NEUTRALLY BUOYANT SUSPENSIONS IN SECOND-ORDER FLUIDS

Abstract

Flow through an inclined tube of a suspension of uniform, neutrally buoyant spheres in a second-order fluid has been analyzed using the theory of (Li and Slattery, 1989) The result predicts that the spheres will migrate toward the center of the tube, forming a core with a maximum packing density. The velocity and concentration distributions agree qualitatively with previous observations. The predicted apparent viscosity is significantly lower than that obtained with a cone-plate viscometer (limiting case in which the angle between the cone and the plate approaches zero) or a parallel-plate viscometer, in which uniform concentration distributions are expected.

KEYWORDS:

• Local volume averaging
• Suspensions
• Second-order fluids
• Spheres
• Tube flow
• Particle migration

Additional information

Notes on contributors

ALFRED C. LI

Present address: Beloit Corporation, Research and Development Center, 1165 Prairie Hill Road, Rockton, Illinois 61072

JOHN C. SLATTERY

Present address: Department of Chemical Engineering, Texas A&M University, College Station, TX 77843–3122.