FEIT Research Project Database

Turbulent plumes with particles in a stratified environment

Project Leader: Jimmy Philip
Primary Contact: Jimmy Philip (jimmyp@unimelb.edu.au)
Keywords: climate change ; fluid dynamics; multiphase flow; turbulence
Disciplines: Mechanical Engineering

In many phenomena that occur in nature, such as bushfires or volcanic eruptions, a hot mass of fluid rises from a relatively compact source up into the atmosphere. These rising hot plumes typically carry particles of varying sizes, from sub-millimeter particles in bushfire plumes to as large as meter-sized rocks in volcanos. The lighter particle-laden plume entrains fluid from the outside environment and becomes denser as it rises. Since the environmental density decreases with increasing altitude, ie, a stably stratified, the plume reaches a height where the plume density is no longer lower than the environmental density. At this height, after a small overshoot, the plume spreads laterally, where the particles can fall off the laterally spreading plume, and can sometimes be re-entrained into the rising plume.

The project will experimentally study the evolution of these particle-laden plumes in a laboratory setup using PIV and PLIF techniques for velocity and density measurements. An experimental image of density in a buoyant plume without particles, and velocity field of plumes with particles are given below.

We will also develop integral models of particle-laden plume evolution starting from the averaged Navier-Stokes equations.

Schematic of a particle-laden plume evolving in a stratified environment.
Left - Experimentally measured density field in plume using PLIF. Right - Particles and fluid velocity using PIV.