Characterizing the lower log region of the atmospheric surface layer via large-scale particle tracking velocimetry

Near-surface snow particle dynamics from particle tracking velocimetry and turbulence measurements during alpine blowing snow storms

“…PTV measurements were calculated by DaVis 8 (LaVision) software and estimated individual snow particle velocities using tracking algorithms that match discrete particles in subsequent frames imaged by the high-speed camera. Particle velocimetry techniques are normally used for wind tunnel studies (e.g., Zhang et al, 2007;Creyssels et al, 2009;Ho et al, 2011Ho et al, , 2012Lü et al, 2012;Tominaga et al, 2012;Groot Zwaaftink et al, 2014;Paterna et al, 2016), with few applications, in any discipline, in an outdoor setting (e.g., Morris et al, 2007;Zhu et al, 2007;Rosi et al, 2014;Toloui et al, 2014). This is the first known application of PTV for boundary-layer blowing snow studies in a natural environment.…”

“…Of the multitude of blowing snow models that have been developed, many implement components of earlier aeolian saltation or initiation models, e.g., the work of Bagnold (1941), Owen (1964), Schmidt (1980), Pomeroy and Gray (1990), and Nishimura and Hunt (2000). In what follows, effort has been made to refer only to the original work containing the model component or measurement campaign under discussion, but comments generally apply to all derivatives.…”

“…The two most commonly modeled modes of saltation initiation are "aerodynamic lift", the direct drag-induced ejections of grains, and "splash", the ejection of grains by rebounding saltating particles (Doorschot and Lehning, 2002;McElwaine et al, 2004). However, there are substantial disagreements about these mechanisms; Schmidt (1980) calculated that direct aerodynamic lift was not possible under average flow conditions over a level snow surface due to strong snow particle bonding. Doorschot et al (2004) argued the fragile dendritic snow in their study resulted in aerodynamic lift dominance.…”

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

“…3D-PTV has great potential to unravel the complex physics of a variety of turbulent flows such as large-scale turbulent motions in the lower atmosphere 25 , indoor air distribution 26 , or pulsatile flows in aortic topology 28 among many others. However, an understanding of its advantages and limitations as well as experience is essential to maximize its potential.…”

On the Lagrangian features of circular and semicircular jets via 3D Particle Tracking Velocimetry

“…In addition, 3D-PTV has been compared with direct numerical simulation (DNS) of plane channel with abrupt expansions [22] and plane Couette flows [23]. Recently, Rosi [24] has used 3D-PTV to resolve flow structures in the lower atmosphere with a domain size of 4 m  2 m  2 m. Since 3D-PTV is not limited to stationary flows, there have been extensive studies on pulsatile flows such as those in micro silicon Y-channels flows [25] and arterial stiffness [26] as well as temporal dispersion in aortic flows [27].…”