The origin of particle streaks in high-Re turbulent boundary layers

Recent changes in climate have led to more extreme wind events, drier soils, and exposed lake beds. Across the Western United States, this has caused increasing amounts of dust in cities such as Phoenix and Salt Lake City. The majority of this dust is not transported in large-scale dust storms, but rather in continuous small-scale dust events. Dust transport in these events is driven by fluctuations rather than bulk transport. One fluctuating feature are the streak-like structures the dust forms above the ground. In order to better predict transport rates, in-depth understanding of the origins and dynamics of these streaks is necessary. Here we perform two-phase measurements of microscopic inertial particles in high-Re turbulent boundary layers. Particles are injected in the boundary layer in the one-way coupled regime. Flow field measurements (PIV) and tracking of inertial particles (PTV) are performed simultaneously. This enables comparison of particle streaks to underlying streaks in the flow. This shows how particle streaks are created and how the flow structures that they sample influence their dynamics.