Radial Distribution of Spherical Particles in Neutrally Buoyant Suspensions Flowing through a Capillary Tube

Abstract

Radial distribution of particles in a capillary tube has been studied on neutrally buoyant suspensions of spherical particles flowing through the tube.. The ranges of the solid volume fraction and the relative particle Reynolds number were 0.05 to 0.205 and 0.048 to 2.0, respectively. Two typical particle distribution patterns were observed. One was an accumulation of particles near the center of the tube, and the other was that of the particles near the annular space whose radius was about a half of the tube radius. The former type was observed at low relative particle Reynolds number and at high solid volume fraction. The latter type was observed at high relative particle Reynolds number and at low solid volume fraction. Increase in the relative particle Reynolds number and decrease in the solid volume fraction changed the particle distribution patterns similarly. All patterns of the particle distribution appeared to be a combination of these two types except that in the suspension having solid volume fraction above 0.2.