Deposition of Newtonian Particles Entrained in a Turbulent Axisymmetric Free Jet

In the past 10 years there has been a significant amount of research into two-phase particle transport. The terrorist events of September 11, 2001 sparked a series of studies analyzing particle entrainment and deposition in turbulent airflows. One area of research needing further attention has been the study of particles entrained in axisymmetric air jets. An experimental rig was designed and built to study entrainment properties and deposition of Newtonian particles, after injection into a turbulent axisymmetric free air jet.

Newtonian spherical particles, ranging from 1mm to 6mm in diameter, were injected into a turbulent airstream and blown through a nozzle into a large, open space. As the particles fell out of the jet stream, their linear distances, from nozzle to initial-ground-contact, were recorded and analyzed.

The experiments conducted indicated particle size and density to be significant factors when considering Newtonian particle entrainment. Additionally, particle deposition distribution revealed a consistent positive skewness, as opposed to an expected Gaussian form.

The data presented in this paper provide a starting point for understanding entrainment of Newtonian spherical particles in jets. The simple experimental rig geometry and results also provide an opportunity for computational fluid dynamics models to be validated, answering a call from the 2006 Annual Review of Fluid Mechanics.