ABSTRACT:

This dataset accompanies the study “Collective transfer of microparticle clouds across the air–water interface”. The experiments investigate the transfer of simultaneously released hydrophilic glass microparticles across a quiescent or weakly turbulent air–water interface, with particular emphasis on collective effects associated with particle size, morphology, and injected mass. Spherical (SPHP) and non-spherical (NSPHP) particles were investigated over four size ranges and several injected masses. The dataset contains the processed experimental data underlying the quantitative results and figures presented in the associated study, including particle size distributions, particle transfer efficiencies, particle-cloud impact characteristics, interfacial spreading velocities derived from PIV measurements, impact and rebound velocities, and quantities used in the energetic analysis of collision-mediated transfer. Measurements of particle-cloud impact footprints obtained from complementary adhesive-substrate experiments are also provided. These data support the characterization of five collective particle-transfer mechanisms and the analysis of size- and morphology-dependent particle transport across the air–water interface.

ABSTRACT:

Predicting solid particle transport in the lowest parts of the atmosphere is a major issue for man-made obstacles in semi-arid regions.
Here, we investigate the effects on solid particle saltation, of square obstacles on the ground with different spacings.
The aerodynamic field is determined by large eddy simulations coupled with an immersed boundary method for the obstacles.
Solid particles are tracked by a Lagrangian approach.
Take-off and rebound models are introduced for the interaction of particles with the wall.
Without particles, fluid velocity profiles are first compared with experiments showing good agreement.
Special focus is put on the recirculation zone that plays an important role in solid particle entrapment.

Particle concentration fields are presented. Accumulation zones are studied regarding the different obstacle spacings as an extension of the aerodynamic scheme by One (1988) to solid particle transport. A deposition peak appears before the first obstacle. When the spacing between the two obstacles is large enough, some particles are trapped within the recirculation and a second deposition peak arises. The streamwise evolution of the horizontal saltation flux shows that the lowest flux downstream of the obstacles is obtained for the highest separation. The deposition rate or the streamwise saltation flux are estimated globally as a function of obstacle spacing. These results illustrate how the numerical tool developed here can be used for assessing air quality in terms of solid particle concentration.