Particle transport in vertical vortex flow

There are numerous situations in nature and industrial flow in which particles are transported by a vortex-flowing fluid. Vortices form that transport sediment to undesirable locations at many hydraulic structures such as intakes and settling basins. Tornadoes transport valuable topsoil from agricultural lands. Vortices formed at bifurcating flows within blood vessels transport blood cells and platelets. Implications also exist for industrial flow in which a fluid is employed to intentionally transport powders or grains to desirable locations. Little is known, however, about the mechanisms and quantities of particles that vortex flow can transport considering the widespread occurrences of these flows.; To explore vortex transport of particles an experimental study was performed in which particles are introduced into a vortex contained within a test section comprised of a clear vertical pipe. The vortex is induced by tangential jets located in the test section just above the point of sediment introduction. The vortex lifts the particles vertically and discharges them out of the test section into piping that conveys them to a container that retains the particles and fluid. The particles that collected in a given time are then weighed and a particle-transport rate is computed. Similarly, the fluid volume retained permits time to be recorded. Quantities varied in the experiments are particle diameter, vortex circulation strength, and vertical axial vortex velocity.; The results are formulated in a dimensional analysis identifying several dimensionless parameters that are correlated with each other, thereby allowing for use by practitioners. Clear water velocity profiles was taken with an Acoustic Doppler Velocimeter (ADV) reveal a flow pattern for combined, rotational and axial flow of a spiraling cylinder of the flow around the circumference of the vortex, a core cylinder of the flow spiraling downward, and an outer region of slowly spirally flow upward.; Results show a threshold value for particle motion of axial velocity, an increasing trend of particle transport rate with increasing axial velocity in the vortex, followed by a decrease in particle transport rate, and then a further increase in particle transport at high axial velocities.