SETTLING VELOCITIES OF TWO EQUAL-SIZED SPHERES FOLLOWING EACH OTHER IN VISCOUS FLUIDS CONTAINED IN CYLINDERS

Abstract

Experimental data are presented for two equal-sized spheres falling along the axis of a cylinder. The two spheres settle with the same velocity as that of a single falling sphere as long as their separation distance is larger than a critical value. When the distance is smaller than the critical value, the two spheres fall faster than a single sphere. The drag on the two spheres is less affected when two spheres fall in a cylinder in comparison to the situation when two spheres fall in an unbounded medium. The data are correlated and shown to agree with numerical calculations.

KEYWORDS:

• Settling velocity
• Particle interactions
• Wall effects
• Bounded fluids
• Hydrodynamic interactions

Additional information

Notes on contributors

PIETER STROEVE

Corresponding author