Characterizing entrainment through diffusion methods on a turbulent water jet

Abstract:

Understanding particle entrainment and ejection during volcanic episodes is essential in quantifying the dispersion of debris and, in turn, contamination zones surrounding the event. A Lagrangian study of an axisymmetric jet was conducted to analyze the interactions of tracer particles at the turbulent/non-turbulent interface. Measurements acquired through particle tracking velocimetry facilitated the visualization of three dimensional, three component Lagrangian trajectories. This technique allows analysis of the evolution of the fluid entrainment and ejection, starting from the exit of the jet up to 50 diameters downstream. Implementation of a diffusion perspective provides a mathematical formalism that can describe how the jet expands downstream when only the jet contains particles and the ambient is unseeded, as is the case during a volcanic eruption.